Question: Who wrote 182 papers dealing with the hibernation of swallows?

Answer: Elliott Coues

Aristotle however suggested that swallows and other birds hibernated. <hl> This belief persisted as late as 1878, when Elliott Coues listed the titles of no less than 182 papers dealing with the hibernation of swallows. <hl> Even the "highly observant" Gilbert White, in his posthumously published 1789 The Natural History of Selborne, quoted a man's story about swallows being found in a chalk cliff collapse "while he was a schoolboy at Brighthelmstone", though the man denied being an eyewitness. However, he also writes that "as to swallows being found in a torpid state during the winter in the Isle of Wight or any part of this country, I never heard any such account worth attending to", and that if early swallows "happen to find frost and snow they immediately withdraw for a time—a circumstance this much more in favour of hiding than migration", since he doubts they would "return for a week or two to warmer latitudes".

Aristotle however suggested that swallows and other birds hibernated. This belief persisted as late as 1878, when <hl> Elliott Coues <hl> listed the titles of no less than 182 papers dealing with the hibernation of swallows. Even the "highly observant" Gilbert White, in his posthumously published 1789 The Natural History of Selborne, quoted a man's story about swallows being found in a chalk cliff collapse "while he was a schoolboy at Brighthelmstone", though the man denied being an eyewitness. However, he also writes that "as to swallows being found in a torpid state during the winter in the Isle of Wight or any part of this country, I never heard any such account worth attending to", and that if early swallows "happen to find frost and snow they immediately withdraw for a time—a circumstance this much more in favour of hiding than migration", since he doubts they would "return for a week or two to warmer latitudes".


Question: Who wrote "The Natural History of Selborne"?

Aristotle however suggested that swallows and other birds hibernated. This belief persisted as late as 1878, when Elliott Coues listed the titles of no less than 182 papers dealing with the hibernation of swallows. Even the "highly observant" Gilbert White, in his posthumously published 1789 The Natural History of Selborne, quoted a man's story about swallows being found in a chalk cliff collapse "while he was a schoolboy at Brighthelmstone", though the man denied being an eyewitness. However, he also writes that "as to swallows being found in a torpid state during the winter in the Isle of Wight or any part of this country, I never heard any such account worth attending to", and that if early swallows "happen to find frost and snow they immediately withdraw for a time—a circumstance this much more in favour of hiding than migration", since he doubts they would "return for a week or two to warmer latitudes".

Answer: Gilbert White

Aristotle however suggested that swallows and other birds hibernated. This belief persisted as late as 1878, when Elliott Coues listed the titles of no less than 182 papers dealing with the hibernation of swallows. <hl> Even the "highly observant" Gilbert White , in his posthumously published 1789 The Natural History of Selborne, quoted a man's story about swallows being found in a chalk cliff collapse "while he was a schoolboy at Brighthelmstone", though the man denied being an eyewitness. <hl> However, he also writes that "as to swallows being found in a torpid state during the winter in the Isle of Wight or any part of this country, I never heard any such account worth attending to", and that if early swallows "happen to find frost and snow they immediately withdraw for a time—a circumstance this much more in favour of hiding than migration", since he doubts they would "return for a week or two to warmer latitudes".

Aristotle however suggested that swallows and other birds hibernated. This belief persisted as late as 1878, when Elliott Coues listed the titles of no less than 182 papers dealing with the hibernation of swallows. Even the "highly observant" <hl> Gilbert White <hl>, in his posthumously published 1789 The Natural History of Selborne, quoted a man's story about swallows being found in a chalk cliff collapse "while he was a schoolboy at Brighthelmstone", though the man denied being an eyewitness. However, he also writes that "as to swallows being found in a torpid state during the winter in the Isle of Wight or any part of this country, I never heard any such account worth attending to", and that if early swallows "happen to find frost and snow they immediately withdraw for a time—a circumstance this much more in favour of hiding than migration", since he doubts they would "return for a week or two to warmer latitudes".

Even the "highly observant" <hl> Gilbert White <hl> , in his posthumously published 1789 The Natural History of Selborne, quoted a man's story about swallows being found in a chalk cliff collapse "while he was a schoolboy at Brighthelmstone", though the man denied being an eyewitness.


Question: When was migration finally accepted?

It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. Thomas Bewick's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward", and states the situation in Britain as follows:

Answer: the end of the eighteenth century

<hl> It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. <hl> Thomas Bewick's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward", and states the situation in Britain as follows:

It was not until <hl> the end of the eighteenth century <hl> that migration as an explanation for the winter disappearance of birds from northern climes was accepted. Thomas Bewick's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward", and states the situation in Britain as follows:


Question: Who wrote A History of British Birds?

Answer: Thomas Bewick

It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. <hl> Thomas Bewick 's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward", and states the situation in Britain as follows: <hl>

It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. <hl> Thomas Bewick <hl>'s A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward", and states the situation in Britain as follows:

<hl> Thomas Bewick <hl> 's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward", and states the situation in Britain as follows:


Question: What year was Thomas Bewick's book published?

Answer: 1797

It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. <hl> Thomas Bewick's A History of British Birds (Volume 1, 1797 ) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward", and states the situation in Britain as follows: <hl>

It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. Thomas Bewick's A History of British Birds (Volume 1, <hl> 1797 <hl>) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward", and states the situation in Britain as follows:

Thomas Bewick's A History of British Birds (Volume 1, <hl> 1797 <hl> ) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward", and states the situation in Britain as follows:


Question: Where were Swallows seen flying?

Answer: between the islands of Minorca and Majorca

It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. <hl> Thomas Bewick's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, " between the islands of Minorca and Majorca , saw great numbers of Swallows flying northward", and states the situation in Britain as follows: <hl>

It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. Thomas Bewick's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "<hl> between the islands of Minorca and Majorca <hl>, saw great numbers of Swallows flying northward", and states the situation in Britain as follows:

Thomas Bewick's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, " <hl> between the islands of Minorca and Majorca <hl> , saw great numbers of Swallows flying northward", and states the situation in Britain as follows:


Question: Which directions were the Swallows flying?

Answer: northward

It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. <hl> Thomas Bewick's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward ", and states the situation in Britain as follows: <hl>

It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. Thomas Bewick's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying <hl> northward <hl>", and states the situation in Britain as follows:

Thomas Bewick's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying <hl> northward <hl> ", and states the situation in Britain as follows:


Question: Who describes an experiment with swallows?

Bewick then describes an experiment which succeeded in keeping swallows alive in Britain for several years, where they remained warm and dry through the winters. He concludes:

Answer: Bewick

<hl> Bewick then describes an experiment which succeeded in keeping swallows alive in Britain for several years, where they remained warm and dry through the winters. <hl> He concludes:

<hl> Bewick <hl> then describes an experiment which succeeded in keeping swallows alive in Britain for several years, where they remained warm and dry through the winters. He concludes:


Question: Where did this experiment take place?

Answer: Britain

<hl> Bewick then describes an experiment which succeeded in keeping swallows alive in Britain for several years, where they remained warm and dry through the winters. <hl> He concludes:

Bewick then describes an experiment which succeeded in keeping swallows alive in <hl> Britain <hl> for several years, where they remained warm and dry through the winters. He concludes:


Question: How did the experiment succeed?

Answer: they remained warm and dry through the winters

<hl> Bewick then describes an experiment which succeeded in keeping swallows alive in Britain for several years, where they remained warm and dry through the winters . <hl> He concludes:

Bewick then describes an experiment which succeeded in keeping swallows alive in Britain for several years, where <hl> they remained warm and dry through the winters <hl>. He concludes:

Bewick then describes an experiment which succeeded in keeping swallows alive in Britain for several years, where <hl> they remained warm and dry through the winters <hl> .


Question: How long did the birds stay alive?

Answer: several years

<hl> Bewick then describes an experiment which succeeded in keeping swallows alive in Britain for several years , where they remained warm and dry through the winters. <hl> He concludes:

Bewick then describes an experiment which succeeded in keeping swallows alive in Britain for <hl> several years <hl>, where they remained warm and dry through the winters. He concludes:

Bewick then describes an experiment which succeeded in keeping swallows alive in Britain for <hl> several years <hl> , where they remained warm and dry through the winters.


Question: Why do birds migrate?

Migration is the regular seasonal movement, often north and south, undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat, or weather. Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. Non-migratory birds are said to be resident or sedentary. Approximately 1800 of the world's 10,000 bird species are long-distance migrants.

Answer: response to changes in food availability, habitat, or weather

Migration is the regular seasonal movement, often north and south, undertaken by many species of birds. <hl> Bird movements include those made in response to changes in food availability, habitat, or weather . <hl> Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. Non-migratory birds are said to be resident or sedentary. Approximately 1800 of the world's 10,000 bird species are long-distance migrants.

Migration is the regular seasonal movement, often north and south, undertaken by many species of birds. Bird movements include those made in <hl> response to changes in food availability, habitat, or weather <hl>. Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. Non-migratory birds are said to be resident or sedentary. Approximately 1800 of the world's 10,000 bird species are long-distance migrants.

Bird movements include those made in <hl> response to changes in food availability, habitat, or weather <hl> .


Question: What are non=migratory birds called?

Answer: resident or sedentary

Migration is the regular seasonal movement, often north and south, undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat, or weather. Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. <hl> Non-migratory birds are said to be resident or sedentary . <hl> Approximately 1800 of the world's 10,000 bird species are long-distance migrants.

Migration is the regular seasonal movement, often north and south, undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat, or weather. Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. Non-migratory birds are said to be <hl> resident or sedentary <hl>. Approximately 1800 of the world's 10,000 bird species are long-distance migrants.

Non-migratory birds are said to be <hl> resident or sedentary <hl> .


Question: How many species of birds are there?

Answer: 10,000

Migration is the regular seasonal movement, often north and south, undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat, or weather. Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. Non-migratory birds are said to be resident or sedentary. <hl> Approximately 1800 of the world's 10,000 bird species are long-distance migrants. <hl>

Migration is the regular seasonal movement, often north and south, undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat, or weather. Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. Non-migratory birds are said to be resident or sedentary. Approximately 1800 of the world's <hl> 10,000 <hl> bird species are long-distance migrants.


Question: How many bird species are long distance migrants?

Answer: 1800

Migration is the regular seasonal movement, often north and south, undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat, or weather. Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. Non-migratory birds are said to be resident or sedentary. <hl> Approximately 1800 of the world's 10,000 bird species are long-distance migrants. <hl>

Migration is the regular seasonal movement, often north and south, undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat, or weather. Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. Non-migratory birds are said to be resident or sedentary. Approximately <hl> 1800 <hl> of the world's 10,000 bird species are long-distance migrants.


Question: Which direction do birds primarily migrate?

Answer: north and south

<hl> Migration is the regular seasonal movement, often north and south , undertaken by many species of birds. <hl> Bird movements include those made in response to changes in food availability, habitat, or weather. Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. Non-migratory birds are said to be resident or sedentary. Approximately 1800 of the world's 10,000 bird species are long-distance migrants.

Migration is the regular seasonal movement, often <hl> north and south <hl>, undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat, or weather. Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Migration is marked by its annual seasonality. Non-migratory birds are said to be resident or sedentary. Approximately 1800 of the world's 10,000 bird species are long-distance migrants.

Migration is the regular seasonal movement, often <hl> north and south <hl> , undertaken by many species of birds.


Question: Along where do many birds migrate?

Many bird populations migrate long distances along a flyway. The most common pattern involves flying north in the spring to breed in the temperate or Arctic summer and returning in the autumn to wintering grounds in warmer regions to the south. Of course, in the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration.

Answer: a flyway

<hl> Many bird populations migrate long distances along a flyway . <hl> The most common pattern involves flying north in the spring to breed in the temperate or Arctic summer and returning in the autumn to wintering grounds in warmer regions to the south. Of course, in the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration.

Many bird populations migrate long distances along <hl> a flyway <hl>. The most common pattern involves flying north in the spring to breed in the temperate or Arctic summer and returning in the autumn to wintering grounds in warmer regions to the south. Of course, in the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration.

Many bird populations migrate long distances along <hl> a flyway <hl> .


Question: What is the most common directionof migration in autumn?

Answer: south

Many bird populations migrate long distances along a flyway. <hl> The most common pattern involves flying north in the spring to breed in the temperate or Arctic summer and returning in the autumn to wintering grounds in warmer regions to the south . <hl> Of course, in the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration.

Many bird populations migrate long distances along a flyway. The most common pattern involves flying north in the spring to breed in the temperate or Arctic summer and returning in the autumn to wintering grounds in warmer regions to the <hl> south <hl>. Of course, in the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration.

The most common pattern involves flying north in the spring to breed in the temperate or Arctic summer and returning in the autumn to wintering grounds in warmer regions to the <hl> south <hl> .


Question: What is the most common pattern of migration in the spring?

Answer: flying north

Many bird populations migrate long distances along a flyway. <hl> The most common pattern involves flying north in the spring to breed in the temperate or Arctic summer and returning in the autumn to wintering grounds in warmer regions to the south. <hl> Of course, in the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration.

Many bird populations migrate long distances along a flyway. The most common pattern involves <hl> flying north <hl> in the spring to breed in the temperate or Arctic summer and returning in the autumn to wintering grounds in warmer regions to the south. Of course, in the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration.


Question: Why do the birds fly north?

Answer: to breed

Many bird populations migrate long distances along a flyway. <hl> The most common pattern involves flying north in the spring to breed in the temperate or Arctic summer and returning in the autumn to wintering grounds in warmer regions to the south. <hl> Of course, in the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration.

Many bird populations migrate long distances along a flyway. The most common pattern involves flying north in the spring <hl> to breed <hl> in the temperate or Arctic summer and returning in the autumn to wintering grounds in warmer regions to the south. Of course, in the southern hemisphere the directions are reversed, but there is less land area in the far south to support long-distance migration.


Question: What is the primary motivation for migration?

The primary motivation for migration appears to be food; for example, some hummingbirds choose not to migrate if fed through the winter. Also, the longer days of the northern summer provide extended time for breeding birds to feed their young. This helps diurnal birds to produce larger clutches than related non-migratory species that remain in the tropics. As the days shorten in autumn, the birds return to warmer regions where the available food supply varies little with the season.

Answer: food

<hl> The primary motivation for migration appears to be food ; for example, some hummingbirds choose not to migrate if fed through the winter. <hl> Also, the longer days of the northern summer provide extended time for breeding birds to feed their young. This helps diurnal birds to produce larger clutches than related non-migratory species that remain in the tropics. As the days shorten in autumn, the birds return to warmer regions where the available food supply varies little with the season.

The primary motivation for migration appears to be <hl> food <hl>; for example, some hummingbirds choose not to migrate if fed through the winter. Also, the longer days of the northern summer provide extended time for breeding birds to feed their young. This helps diurnal birds to produce larger clutches than related non-migratory species that remain in the tropics. As the days shorten in autumn, the birds return to warmer regions where the available food supply varies little with the season.

The primary motivation for migration appears to be <hl> food <hl> ; for example, some hummingbirds choose not to migrate if fed through the winter.


Question: Which birds will not migrate if they are well fed through winter?

Answer: hummingbirds

<hl> The primary motivation for migration appears to be food; for example, some hummingbirds choose not to migrate if fed through the winter. <hl> Also, the longer days of the northern summer provide extended time for breeding birds to feed their young. This helps diurnal birds to produce larger clutches than related non-migratory species that remain in the tropics. As the days shorten in autumn, the birds return to warmer regions where the available food supply varies little with the season.

The primary motivation for migration appears to be food; for example, some <hl> hummingbirds <hl> choose not to migrate if fed through the winter. Also, the longer days of the northern summer provide extended time for breeding birds to feed their young. This helps diurnal birds to produce larger clutches than related non-migratory species that remain in the tropics. As the days shorten in autumn, the birds return to warmer regions where the available food supply varies little with the season.


Question: When do the birds return to warmer regions?

Answer: autumn

The primary motivation for migration appears to be food; for example, some hummingbirds choose not to migrate if fed through the winter. Also, the longer days of the northern summer provide extended time for breeding birds to feed their young. This helps diurnal birds to produce larger clutches than related non-migratory species that remain in the tropics. <hl> As the days shorten in autumn , the birds return to warmer regions where the available food supply varies little with the season. <hl>

The primary motivation for migration appears to be food; for example, some hummingbirds choose not to migrate if fed through the winter. Also, the longer days of the northern summer provide extended time for breeding birds to feed their young. This helps diurnal birds to produce larger clutches than related non-migratory species that remain in the tropics. As the days shorten in <hl> autumn <hl>, the birds return to warmer regions where the available food supply varies little with the season.

As the days shorten in <hl> autumn <hl> , the birds return to warmer regions where the available food supply varies little with the season.


Question: what do the longer days of summer provide the birds?

Answer: time for breeding birds to feed their young.

The primary motivation for migration appears to be food; for example, some hummingbirds choose not to migrate if fed through the winter. <hl> Also, the longer days of the northern summer provide extended time for breeding birds to feed their young. This helps diurnal birds to produce larger clutches than related non-migratory species that remain in the tropics. <hl> As the days shorten in autumn, the birds return to warmer regions where the available food supply varies little with the season.

The primary motivation for migration appears to be food; for example, some hummingbirds choose not to migrate if fed through the winter. Also, the longer days of the northern summer provide extended <hl> time for breeding birds to feed their young. <hl> This helps diurnal birds to produce larger clutches than related non-migratory species that remain in the tropics. As the days shorten in autumn, the birds return to warmer regions where the available food supply varies little with the season.


Question: What do diurnal birds produce as opposed to non migratory species?

Answer: larger clutches

The primary motivation for migration appears to be food; for example, some hummingbirds choose not to migrate if fed through the winter. Also, the longer days of the northern summer provide extended time for breeding birds to feed their young. <hl> This helps diurnal birds to produce larger clutches than related non-migratory species that remain in the tropics. <hl> As the days shorten in autumn, the birds return to warmer regions where the available food supply varies little with the season.

The primary motivation for migration appears to be food; for example, some hummingbirds choose not to migrate if fed through the winter. Also, the longer days of the northern summer provide extended time for breeding birds to feed their young. This helps diurnal birds to produce <hl> larger clutches <hl> than related non-migratory species that remain in the tropics. As the days shorten in autumn, the birds return to warmer regions where the available food supply varies little with the season.


Question: What is hightened during migration?

These advantages offset the high stress, physical exertion costs, and other risks of the migration. Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands, has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants, which it feeds to its young. A similar strategy is adopted by the greater noctule bat, which preys on nocturnal passerine migrants. The higher concentrations of migrating birds at stopover sites make them prone to parasites and pathogens, which require a heightened immune response.

Answer: Predation

These advantages offset the high stress, physical exertion costs, and other risks of the migration. <hl> Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands, has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants, which it feeds to its young. <hl> A similar strategy is adopted by the greater noctule bat, which preys on nocturnal passerine migrants. The higher concentrations of migrating birds at stopover sites make them prone to parasites and pathogens, which require a heightened immune response.

These advantages offset the high stress, physical exertion costs, and other risks of the migration. <hl> Predation <hl> can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands, has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants, which it feeds to its young. A similar strategy is adopted by the greater noctule bat, which preys on nocturnal passerine migrants. The higher concentrations of migrating birds at stopover sites make them prone to parasites and pathogens, which require a heightened immune response.


Question: Where do Eleonora's falcon breed?

Answer: Mediterranean islands

These advantages offset the high stress, physical exertion costs, and other risks of the migration. <hl> Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands , has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants, which it feeds to its young. <hl> A similar strategy is adopted by the greater noctule bat, which preys on nocturnal passerine migrants. The higher concentrations of migrating birds at stopover sites make them prone to parasites and pathogens, which require a heightened immune response.

These advantages offset the high stress, physical exertion costs, and other risks of the migration. Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on <hl> Mediterranean islands <hl>, has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants, which it feeds to its young. A similar strategy is adopted by the greater noctule bat, which preys on nocturnal passerine migrants. The higher concentrations of migrating birds at stopover sites make them prone to parasites and pathogens, which require a heightened immune response.

Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on <hl> Mediterranean islands <hl> , has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants, which it feeds to its young.


Question: What do Eleonora's falcon feed their young?

Answer: southbound passerine migrants

These advantages offset the high stress, physical exertion costs, and other risks of the migration. <hl> Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands, has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants , which it feeds to its young. <hl> A similar strategy is adopted by the greater noctule bat, which preys on nocturnal passerine migrants. The higher concentrations of migrating birds at stopover sites make them prone to parasites and pathogens, which require a heightened immune response.

These advantages offset the high stress, physical exertion costs, and other risks of the migration. Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands, has a very late breeding season, coordinated with the autumn passage of <hl> southbound passerine migrants <hl>, which it feeds to its young. A similar strategy is adopted by the greater noctule bat, which preys on nocturnal passerine migrants. The higher concentrations of migrating birds at stopover sites make them prone to parasites and pathogens, which require a heightened immune response.

Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands, has a very late breeding season, coordinated with the autumn passage of <hl> southbound passerine migrants <hl> , which it feeds to its young.


Question: What preys on nocturnal passerine migrants?

Answer: the greater noctule bat

These advantages offset the high stress, physical exertion costs, and other risks of the migration. Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands, has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants, which it feeds to its young. <hl> A similar strategy is adopted by the greater noctule bat , which preys on nocturnal passerine migrants. <hl> The higher concentrations of migrating birds at stopover sites make them prone to parasites and pathogens, which require a heightened immune response.

These advantages offset the high stress, physical exertion costs, and other risks of the migration. Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands, has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants, which it feeds to its young. A similar strategy is adopted by <hl> the greater noctule bat <hl>, which preys on nocturnal passerine migrants. The higher concentrations of migrating birds at stopover sites make them prone to parasites and pathogens, which require a heightened immune response.

A similar strategy is adopted by <hl> the greater noctule bat <hl> , which preys on nocturnal passerine migrants.


Question: What makes birds prone to parasites and pathogens?

Answer: higher concentrations of migrating birds

These advantages offset the high stress, physical exertion costs, and other risks of the migration. Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands, has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants, which it feeds to its young. A similar strategy is adopted by the greater noctule bat, which preys on nocturnal passerine migrants. <hl> The higher concentrations of migrating birds at stopover sites make them prone to parasites and pathogens, which require a heightened immune response. <hl>

These advantages offset the high stress, physical exertion costs, and other risks of the migration. Predation can be heightened during migration: Eleonora's falcon Falco eleonorae, which breeds on Mediterranean islands, has a very late breeding season, coordinated with the autumn passage of southbound passerine migrants, which it feeds to its young. A similar strategy is adopted by the greater noctule bat, which preys on nocturnal passerine migrants. The <hl> higher concentrations of migrating birds <hl> at stopover sites make them prone to parasites and pathogens, which require a heightened immune response.


Question: What is partial migration?

Within a species not all populations may be migratory; this is known as "partial migration". Partial migration is very common in the southern continents; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (birds that nest at higher latitudes spend the winter at lower latitudes), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.

Answer: not all populations may be migratory

<hl> Within a species not all populations may be migratory ; this is known as "partial migration". <hl> Partial migration is very common in the southern continents; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (birds that nest at higher latitudes spend the winter at lower latitudes), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.

Within a species <hl> not all populations may be migratory <hl>; this is known as "partial migration". Partial migration is very common in the southern continents; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (birds that nest at higher latitudes spend the winter at lower latitudes), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.

Within a species <hl> not all populations may be migratory <hl> ; this is known as "partial migration".


Question: Where is partial migration most common?

Answer: the southern continents

Within a species not all populations may be migratory; this is known as "partial migration". <hl> Partial migration is very common in the southern continents ; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. <hl> In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (birds that nest at higher latitudes spend the winter at lower latitudes), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.

Within a species not all populations may be migratory; this is known as "partial migration". Partial migration is very common in <hl> the southern continents <hl>; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (birds that nest at higher latitudes spend the winter at lower latitudes), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.

Partial migration is very common in <hl> the southern continents <hl> ; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory.


Question: In Australia, what percent of non-passerine birds are partially migratory?

Answer: 44%

Within a species not all populations may be migratory; this is known as "partial migration". <hl> Partial migration is very common in the southern continents; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. <hl> In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (birds that nest at higher latitudes spend the winter at lower latitudes), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.

Within a species not all populations may be migratory; this is known as "partial migration". Partial migration is very common in the southern continents; in Australia, <hl> 44% <hl> of non-passerine birds and 32% of passerine species are partially migratory. In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (birds that nest at higher latitudes spend the winter at lower latitudes), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.


Question: In Australia, what percent of passerine species are partially migratory?

Answer: 32%

Within a species not all populations may be migratory; this is known as "partial migration". <hl> Partial migration is very common in the southern continents; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. <hl> In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (birds that nest at higher latitudes spend the winter at lower latitudes), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.

Within a species not all populations may be migratory; this is known as "partial migration". Partial migration is very common in the southern continents; in Australia, 44% of non-passerine birds and <hl> 32% <hl> of passerine species are partially migratory. In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (birds that nest at higher latitudes spend the winter at lower latitudes), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.


Question: What is leap frog migration?

Answer: birds that nest at higher latitudes spend the winter at lower latitudes

Within a species not all populations may be migratory; this is known as "partial migration". Partial migration is very common in the southern continents; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. <hl> Many fully migratory species show leap-frog migration ( birds that nest at higher latitudes spend the winter at lower latitudes ), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order. <hl>

Within a species not all populations may be migratory; this is known as "partial migration". Partial migration is very common in the southern continents; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (<hl> birds that nest at higher latitudes spend the winter at lower latitudes <hl>), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.

Many fully migratory species show leap-frog migration ( <hl> birds that nest at higher latitudes spend the winter at lower latitudes <hl> ), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.


Question: Which sex of the chaffinches Fringilla coelebs migrate earlier?

Within a population, it is common for different ages and/or sexes to have different patterns of timing and distance. Female chaffinches Fringilla coelebs in Eastern Fennoscandia migrate earlier in the autumn than males do.

Answer: Female

Within a population, it is common for different ages and/or sexes to have different patterns of timing and distance. <hl> Female chaffinches Fringilla coelebs in Eastern Fennoscandia migrate earlier in the autumn than males do. <hl>

Within a population, it is common for different ages and/or sexes to have different patterns of timing and distance. <hl> Female <hl> chaffinches Fringilla coelebs in Eastern Fennoscandia migrate earlier in the autumn than males do.


Question: Where are chaffinches Fringilla coelebs from?

Answer: Eastern Fennoscandia

Within a population, it is common for different ages and/or sexes to have different patterns of timing and distance. <hl> Female chaffinches Fringilla coelebs in Eastern Fennoscandia migrate earlier in the autumn than males do. <hl>

Within a population, it is common for different ages and/or sexes to have different patterns of timing and distance. Female chaffinches Fringilla coelebs in <hl> Eastern Fennoscandia <hl> migrate earlier in the autumn than males do.


Question: When do the chaffinches Fringilla coelebs migrate?

Answer: autumn

Within a population, it is common for different ages and/or sexes to have different patterns of timing and distance. <hl> Female chaffinches Fringilla coelebs in Eastern Fennoscandia migrate earlier in the autumn than males do. <hl>

Within a population, it is common for different ages and/or sexes to have different patterns of timing and distance. Female chaffinches Fringilla coelebs in Eastern Fennoscandia migrate earlier in the <hl> autumn <hl> than males do.


Question: How do most migrations begin?

Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed flyways. These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.

Answer: the birds starting off in a broad front

<hl> Most migrations begin with the birds starting off in a broad front . <hl> Often, this front narrows into one or more preferred routes termed flyways. These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.

Most migrations begin with <hl> the birds starting off in a broad front <hl>. Often, this front narrows into one or more preferred routes termed flyways. These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.

Most migrations begin with <hl> the birds starting off in a broad front <hl> .


Question: What to the migrating birds usually follow?

Answer: mountain ranges or coastlines

Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed flyways. <hl> These routes typically follow mountain ranges or coastlines , sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. <hl> The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.

Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed flyways. These routes typically follow <hl> mountain ranges or coastlines <hl>, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.

These routes typically follow <hl> mountain ranges or coastlines <hl> , sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water.


Question: What obsticals will migrating birds avoid?

Answer: large stretches of open water

Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed flyways. <hl> These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water . <hl> The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.

Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed flyways. These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as <hl> large stretches of open water <hl>. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.

These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as <hl> large stretches of open water <hl> .


Question: What is a common pattern in North America migration?

Answer: clockwise

Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed flyways. These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. <hl> A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards. <hl>

Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed flyways. These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is <hl> clockwise <hl> migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.


Question: What are the preferred routes for migration called?

Answer: flyways

Most migrations begin with the birds starting off in a broad front. <hl> Often, this front narrows into one or more preferred routes termed flyways . <hl> These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.

Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed <hl> flyways <hl>. These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.

Often, this front narrows into one or more preferred routes termed <hl> flyways <hl> .


Question: How do most birds migrate?

Many, if not most, birds migrate in flocks. For larger birds, flying in flocks reduces the energy cost. Geese in a V-formation may conserve 12–20% of the energy they would need to fly alone. Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h (3.1 mph) faster in flocks than when they were flying alone.

Answer: in flocks

<hl> Many, if not most, birds migrate in flocks . <hl> For larger birds, flying in flocks reduces the energy cost. Geese in a V-formation may conserve 12–20% of the energy they would need to fly alone. Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h (3.1 mph) faster in flocks than when they were flying alone.

Many, if not most, birds migrate <hl> in flocks <hl>. For larger birds, flying in flocks reduces the energy cost. Geese in a V-formation may conserve 12–20% of the energy they would need to fly alone. Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h (3.1 mph) faster in flocks than when they were flying alone.

Many, if not most, birds migrate <hl> in flocks <hl> .


Question: How much energy do geese conserve flying in a flock?

Answer: 12–20%

Many, if not most, birds migrate in flocks. For larger birds, flying in flocks reduces the energy cost. <hl> Geese in a V-formation may conserve 12–20% of the energy they would need to fly alone. <hl> Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h (3.1 mph) faster in flocks than when they were flying alone.

Many, if not most, birds migrate in flocks. For larger birds, flying in flocks reduces the energy cost. Geese in a V-formation may conserve <hl> 12–20% <hl> of the energy they would need to fly alone. Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h (3.1 mph) faster in flocks than when they were flying alone.


Question: How much faster do Red knots and dunlins fly in a flock?

Answer: 3.1 mph

Many, if not most, birds migrate in flocks. For larger birds, flying in flocks reduces the energy cost. Geese in a V-formation may conserve 12–20% of the energy they would need to fly alone. <hl> Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h ( 3.1 mph ) faster in flocks than when they were flying alone. <hl>

Many, if not most, birds migrate in flocks. For larger birds, flying in flocks reduces the energy cost. Geese in a V-formation may conserve 12–20% of the energy they would need to fly alone. Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h (<hl> 3.1 mph <hl>) faster in flocks than when they were flying alone.

Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h ( <hl> 3.1 mph <hl> ) faster in flocks than when they were flying alone.


Question: What does flying in flocks reduce?

Answer: energy cost

Many, if not most, birds migrate in flocks. <hl> For larger birds, flying in flocks reduces the energy cost . <hl> Geese in a V-formation may conserve 12–20% of the energy they would need to fly alone. Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h (3.1 mph) faster in flocks than when they were flying alone.

Many, if not most, birds migrate in flocks. For larger birds, flying in flocks reduces the <hl> energy cost <hl>. Geese in a V-formation may conserve 12–20% of the energy they would need to fly alone. Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h (3.1 mph) faster in flocks than when they were flying alone.

For larger birds, flying in flocks reduces the <hl> energy cost <hl> .


Question: How do birds conserve energy?

Answer: a V-formation

Many, if not most, birds migrate in flocks. For larger birds, flying in flocks reduces the energy cost. <hl> Geese in a V-formation may conserve 12–20% of the energy they would need to fly alone. <hl> Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h (3.1 mph) faster in flocks than when they were flying alone.

Many, if not most, birds migrate in flocks. For larger birds, flying in flocks reduces the energy cost. Geese in <hl> a V-formation <hl> may conserve 12–20% of the energy they would need to fly alone. Red knots Calidris canutus and dunlins Calidris alpina were found in radar studies to fly 5 km/h (3.1 mph) faster in flocks than when they were flying alone.


Question: What part of birds was found on an expedition to Mt. Everest?

Birds fly at varying altitudes during migration. An expedition to Mt. Everest found skeletons of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. Bar-headed geese Anser indicus have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of 150 to 600 m (490 to 1,970 ft). Bird strike aviation records from the United States show most collisions occur below 600 m (2,000 ft) and almost none above 1,800 m (5,900 ft).

Answer: skeletons

Birds fly at varying altitudes during migration. <hl> An expedition to Mt. Everest found skeletons of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. <hl> Bar-headed geese Anser indicus have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of 150 to 600 m (490 to 1,970 ft). Bird strike aviation records from the United States show most collisions occur below 600 m (2,000 ft) and almost none above 1,800 m (5,900 ft).

Birds fly at varying altitudes during migration. An expedition to Mt. Everest found <hl> skeletons <hl> of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. Bar-headed geese Anser indicus have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of 150 to 600 m (490 to 1,970 ft). Bird strike aviation records from the United States show most collisions occur below 600 m (2,000 ft) and almost none above 1,800 m (5,900 ft).


Question: Which birds have the highest rates of climb to altitude?

Answer: Bar-headed geese Anser indicus

Birds fly at varying altitudes during migration. An expedition to Mt. Everest found skeletons of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. <hl> Bar-headed geese Anser indicus have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. <hl> Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of 150 to 600 m (490 to 1,970 ft). Bird strike aviation records from the United States show most collisions occur below 600 m (2,000 ft) and almost none above 1,800 m (5,900 ft).

Birds fly at varying altitudes during migration. An expedition to Mt. Everest found skeletons of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. <hl> Bar-headed geese Anser indicus <hl> have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of 150 to 600 m (490 to 1,970 ft). Bird strike aviation records from the United States show most collisions occur below 600 m (2,000 ft) and almost none above 1,800 m (5,900 ft).


Question: What kind of birds fly low over water?

Answer: Seabirds

Birds fly at varying altitudes during migration. An expedition to Mt. Everest found skeletons of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. Bar-headed geese Anser indicus have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. <hl> Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. <hl> However most bird migration is in the range of 150 to 600 m (490 to 1,970 ft). Bird strike aviation records from the United States show most collisions occur below 600 m (2,000 ft) and almost none above 1,800 m (5,900 ft).

Birds fly at varying altitudes during migration. An expedition to Mt. Everest found skeletons of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. Bar-headed geese Anser indicus have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. <hl> Seabirds <hl> fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of 150 to 600 m (490 to 1,970 ft). Bird strike aviation records from the United States show most collisions occur below 600 m (2,000 ft) and almost none above 1,800 m (5,900 ft).


Question: What altitude range is most migration recorded?

Answer: 150 to 600 m

Birds fly at varying altitudes during migration. An expedition to Mt. Everest found skeletons of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. Bar-headed geese Anser indicus have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. <hl> However most bird migration is in the range of 150 to 600 m (490 to 1,970 ft). <hl> Bird strike aviation records from the United States show most collisions occur below 600 m (2,000 ft) and almost none above 1,800 m (5,900 ft).

Birds fly at varying altitudes during migration. An expedition to Mt. Everest found skeletons of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. Bar-headed geese Anser indicus have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of <hl> 150 to 600 m <hl> (490 to 1,970 ft). Bird strike aviation records from the United States show most collisions occur below 600 m (2,000 ft) and almost none above 1,800 m (5,900 ft).


Question: Where do most in air collisions occur?

Answer: below 600 m

Birds fly at varying altitudes during migration. An expedition to Mt. Everest found skeletons of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. Bar-headed geese Anser indicus have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of 150 to 600 m (490 to 1,970 ft). <hl> Bird strike aviation records from the United States show most collisions occur below 600 m (2,000 ft) and almost none above 1,800 m (5,900 ft). <hl>

Birds fly at varying altitudes during migration. An expedition to Mt. Everest found skeletons of northern pintail Anas acuta and black-tailed godwit Limosa limosa at 5,000 m (16,000 ft) on the Khumbu Glacier. Bar-headed geese Anser indicus have been recorded by GPS flying at up to 6,540 metres (21,460 ft) while crossing the Himalayas, at the same time engaging in the highest rates of climb to altitude for any bird. Anecdotal reports of them flying much higher have yet to be corroborated with any direct evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of 150 to 600 m (490 to 1,970 ft). Bird strike aviation records from the United States show most collisions occur <hl> below 600 m <hl> (2,000 ft) and almost none above 1,800 m (5,900 ft).


Question: How do penguins migrate?

Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. These routes can cover over 1,000 km (620 mi). Dusky grouse Dendragapus obscurus perform altitudinal migration mostly by walking. Emus Dromaius novaehollandiae in Australia have been observed to undertake long-distance movements on foot during droughts.

Answer: by swimming

Bird migration is not limited to birds that can fly. <hl> Most species of penguin (Spheniscidae) migrate by swimming . <hl> These routes can cover over 1,000 km (620 mi). Dusky grouse Dendragapus obscurus perform altitudinal migration mostly by walking. Emus Dromaius novaehollandiae in Australia have been observed to undertake long-distance movements on foot during droughts.

Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate <hl> by swimming <hl>. These routes can cover over 1,000 km (620 mi). Dusky grouse Dendragapus obscurus perform altitudinal migration mostly by walking. Emus Dromaius novaehollandiae in Australia have been observed to undertake long-distance movements on foot during droughts.

Most species of penguin (Spheniscidae) migrate <hl> by swimming <hl> .


Question: How far do penguins travel when they migrate?

Answer: over 1,000 km

Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. <hl> These routes can cover over 1,000 km (620 mi). <hl> Dusky grouse Dendragapus obscurus perform altitudinal migration mostly by walking. Emus Dromaius novaehollandiae in Australia have been observed to undertake long-distance movements on foot during droughts.

Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. These routes can cover <hl> over 1,000 km <hl> (620 mi). Dusky grouse Dendragapus obscurus perform altitudinal migration mostly by walking. Emus Dromaius novaehollandiae in Australia have been observed to undertake long-distance movements on foot during droughts.


Question: How do Dusky grouse migrate?

Answer: mostly by walking

Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. These routes can cover over 1,000 km (620 mi). <hl> Dusky grouse Dendragapus obscurus perform altitudinal migration mostly by walking . <hl> Emus Dromaius novaehollandiae in Australia have been observed to undertake long-distance movements on foot during droughts.

Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. These routes can cover over 1,000 km (620 mi). Dusky grouse Dendragapus obscurus perform altitudinal migration <hl> mostly by walking <hl>. Emus Dromaius novaehollandiae in Australia have been observed to undertake long-distance movements on foot during droughts.

Dusky grouse Dendragapus obscurus perform altitudinal migration <hl> mostly by walking <hl> .


Question: How do Emus migrate long distances during droughts?

Answer: on foot

Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. These routes can cover over 1,000 km (620 mi). Dusky grouse Dendragapus obscurus perform altitudinal migration mostly by walking. <hl> Emus Dromaius novaehollandiae in Australia have been observed to undertake long-distance movements on foot during droughts. <hl>

Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. These routes can cover over 1,000 km (620 mi). Dusky grouse Dendragapus obscurus perform altitudinal migration mostly by walking. Emus Dromaius novaehollandiae in Australia have been observed to undertake long-distance movements <hl> on foot <hl> during droughts.


Question: Where are Emus from?

Answer: Australia

Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. These routes can cover over 1,000 km (620 mi). Dusky grouse Dendragapus obscurus perform altitudinal migration mostly by walking. <hl> Emus Dromaius novaehollandiae in Australia have been observed to undertake long-distance movements on foot during droughts. <hl>

Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. These routes can cover over 1,000 km (620 mi). Dusky grouse Dendragapus obscurus perform altitudinal migration mostly by walking. Emus Dromaius novaehollandiae in <hl> Australia <hl> have been observed to undertake long-distance movements on foot during droughts.


Question: Where do the pink-footed goose migrate?

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in Africa.

Answer: from Iceland to Britain

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. <hl> For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. <hl> Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in Africa.

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. For example, the pink-footed goose Anser brachyrhynchus migrates <hl> from Iceland to Britain <hl> and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in Africa.


Question: Where do the dark-eyed junco migrate?

Answer: arctic climates to the contiguous United States

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. <hl> For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. <hl> Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in Africa.

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and <hl> arctic climates to the contiguous United States <hl> and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in Africa.


Question: Where do the European pied flycatcher breed?

Answer: Asia and Europe

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. <hl> The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in Africa. <hl>

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in <hl> Asia and Europe <hl> and wintering in Africa.


Question: Where does the European pied flycatcher spend the winter?

Answer: Africa

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. <hl> The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in Africa . <hl>

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in <hl> Africa <hl>.

The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in <hl> Africa <hl> .


Question: How do young learn migratory routes?

Answer: during their first migration with their parents

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. <hl> Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents . <hl> Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in Africa.

The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. Migratory routes and wintering grounds are traditional and learned by young <hl> during their first migration with their parents <hl>. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in Africa.

Migratory routes and wintering grounds are traditional and learned by young <hl> during their first migration with their parents <hl> .


Question: What route does a migrating bird usually follow?

Often, the migration route of a long-distance migrator bird doesn't follow a straight line between breeding and wintering grounds. Rather, it could follow an hooked or arched line, with detours around geographical barriers. For most land-birds, such barriers could consist in seas, large water bodies or high mountain ranges, because of the lack of stopover or feeding sites, or the lack of thermal columns for broad-winged birds.

Answer: an hooked or arched line

Often, the migration route of a long-distance migrator bird doesn't follow a straight line between breeding and wintering grounds. <hl> Rather, it could follow an hooked or arched line , with detours around geographical barriers. <hl> For most land-birds, such barriers could consist in seas, large water bodies or high mountain ranges, because of the lack of stopover or feeding sites, or the lack of thermal columns for broad-winged birds.

Often, the migration route of a long-distance migrator bird doesn't follow a straight line between breeding and wintering grounds. Rather, it could follow <hl> an hooked or arched line <hl>, with detours around geographical barriers. For most land-birds, such barriers could consist in seas, large water bodies or high mountain ranges, because of the lack of stopover or feeding sites, or the lack of thermal columns for broad-winged birds.

Rather, it could follow <hl> an hooked or arched line <hl> , with detours around geographical barriers.


Question: What geographical barriers to land birds try to avoid?

Answer: large water bodies or high mountain ranges

Often, the migration route of a long-distance migrator bird doesn't follow a straight line between breeding and wintering grounds. Rather, it could follow an hooked or arched line, with detours around geographical barriers. <hl> For most land-birds, such barriers could consist in seas, large water bodies or high mountain ranges , because of the lack of stopover or feeding sites, or the lack of thermal columns for broad-winged birds. <hl>

Often, the migration route of a long-distance migrator bird doesn't follow a straight line between breeding and wintering grounds. Rather, it could follow an hooked or arched line, with detours around geographical barriers. For most land-birds, such barriers could consist in seas, <hl> large water bodies or high mountain ranges <hl>, because of the lack of stopover or feeding sites, or the lack of thermal columns for broad-winged birds.

For most land-birds, such barriers could consist in seas, <hl> large water bodies or high mountain ranges <hl> , because of the lack of stopover or feeding sites, or the lack of thermal columns for broad-winged birds.


Question: Why do migrating land birds avoid large water bodies or mountain ranges?

Answer: the lack of stopover or feeding sites

Often, the migration route of a long-distance migrator bird doesn't follow a straight line between breeding and wintering grounds. Rather, it could follow an hooked or arched line, with detours around geographical barriers. <hl> For most land-birds, such barriers could consist in seas, large water bodies or high mountain ranges, because of the lack of stopover or feeding sites , or the lack of thermal columns for broad-winged birds. <hl>

Often, the migration route of a long-distance migrator bird doesn't follow a straight line between breeding and wintering grounds. Rather, it could follow an hooked or arched line, with detours around geographical barriers. For most land-birds, such barriers could consist in seas, large water bodies or high mountain ranges, because of <hl> the lack of stopover or feeding sites <hl>, or the lack of thermal columns for broad-winged birds.

For most land-birds, such barriers could consist in seas, large water bodies or high mountain ranges, because of <hl> the lack of stopover or feeding sites <hl> , or the lack of thermal columns for broad-winged birds.


Question: Why do broad winged birds avoid geographical barriers?

Answer: lack of thermal columns

Often, the migration route of a long-distance migrator bird doesn't follow a straight line between breeding and wintering grounds. Rather, it could follow an hooked or arched line, with detours around geographical barriers. <hl> For most land-birds, such barriers could consist in seas, large water bodies or high mountain ranges, because of the lack of stopover or feeding sites, or the lack of thermal columns for broad-winged birds. <hl>

Often, the migration route of a long-distance migrator bird doesn't follow a straight line between breeding and wintering grounds. Rather, it could follow an hooked or arched line, with detours around geographical barriers. For most land-birds, such barriers could consist in seas, large water bodies or high mountain ranges, because of the lack of stopover or feeding sites, or the <hl> lack of thermal columns <hl> for broad-winged birds.


Question: What do water birds avoid while migrating?

The same considerations about barriers and detours that apply to long-distance land-bird migration apply to water birds, but in reverse: a large area of land without bodies of water that offer feeding sites may also be a barrier to a bird that feeds in coastal waters. Detours avoiding such barriers are observed: for example, brent geese Branta bernicla migrating from the Taymyr Peninsula to the Wadden Sea travel via the White Sea coast and the Baltic Sea rather than directly across the Arctic Ocean and northern Scandinavia.

Answer: a large area of land without bodies of water

<hl> The same considerations about barriers and detours that apply to long-distance land-bird migration apply to water birds, but in reverse: a large area of land without bodies of water that offer feeding sites may also be a barrier to a bird that feeds in coastal waters. <hl> Detours avoiding such barriers are observed: for example, brent geese Branta bernicla migrating from the Taymyr Peninsula to the Wadden Sea travel via the White Sea coast and the Baltic Sea rather than directly across the Arctic Ocean and northern Scandinavia.

The same considerations about barriers and detours that apply to long-distance land-bird migration apply to water birds, but in reverse: <hl> a large area of land without bodies of water <hl> that offer feeding sites may also be a barrier to a bird that feeds in coastal waters. Detours avoiding such barriers are observed: for example, brent geese Branta bernicla migrating from the Taymyr Peninsula to the Wadden Sea travel via the White Sea coast and the Baltic Sea rather than directly across the Arctic Ocean and northern Scandinavia.


Question: Where do brent geese migrate from?

Answer: the Taymyr Peninsula

The same considerations about barriers and detours that apply to long-distance land-bird migration apply to water birds, but in reverse: a large area of land without bodies of water that offer feeding sites may also be a barrier to a bird that feeds in coastal waters. <hl> Detours avoiding such barriers are observed: for example, brent geese Branta bernicla migrating from the Taymyr Peninsula to the Wadden Sea travel via the White Sea coast and the Baltic Sea rather than directly across the Arctic Ocean and northern Scandinavia. <hl>

The same considerations about barriers and detours that apply to long-distance land-bird migration apply to water birds, but in reverse: a large area of land without bodies of water that offer feeding sites may also be a barrier to a bird that feeds in coastal waters. Detours avoiding such barriers are observed: for example, brent geese Branta bernicla migrating from <hl> the Taymyr Peninsula <hl> to the Wadden Sea travel via the White Sea coast and the Baltic Sea rather than directly across the Arctic Ocean and northern Scandinavia.


Question: Where do brent geese migrate to?

Answer: the Wadden Sea

The same considerations about barriers and detours that apply to long-distance land-bird migration apply to water birds, but in reverse: a large area of land without bodies of water that offer feeding sites may also be a barrier to a bird that feeds in coastal waters. <hl> Detours avoiding such barriers are observed: for example, brent geese Branta bernicla migrating from the Taymyr Peninsula to the Wadden Sea travel via the White Sea coast and the Baltic Sea rather than directly across the Arctic Ocean and northern Scandinavia. <hl>

The same considerations about barriers and detours that apply to long-distance land-bird migration apply to water birds, but in reverse: a large area of land without bodies of water that offer feeding sites may also be a barrier to a bird that feeds in coastal waters. Detours avoiding such barriers are observed: for example, brent geese Branta bernicla migrating from the Taymyr Peninsula to <hl> the Wadden Sea <hl> travel via the White Sea coast and the Baltic Sea rather than directly across the Arctic Ocean and northern Scandinavia.