Question: When do caged birds change their preferential direction?

Answer: the same time their wild conspecifics change course

The primary physiological cue for migration are the changes in the day length. These changes are also related to hormonal changes in the birds. In the period before migration, many birds display higher activity or Zugunruhe (German: migratory restlessness), first described by Johann Friedrich Naumann in 1795, as well as physiological changes such as increased fat deposition. The occurrence of Zugunruhe even in cage-raised birds with no environmental cues (e.g. shortening of day and falling temperature) has pointed to the role of circannual endogenous programs in controlling bird migrations. <hl> Caged birds display a preferential flight direction that corresponds with the migratory direction they would take in nature, changing their preferential direction at roughly the same time their wild conspecifics change course . <hl>

The primary physiological cue for migration are the changes in the day length. These changes are also related to hormonal changes in the birds. In the period before migration, many birds display higher activity or Zugunruhe (German: migratory restlessness), first described by Johann Friedrich Naumann in 1795, as well as physiological changes such as increased fat deposition. The occurrence of Zugunruhe even in cage-raised birds with no environmental cues (e.g. shortening of day and falling temperature) has pointed to the role of circannual endogenous programs in controlling bird migrations. Caged birds display a preferential flight direction that corresponds with the migratory direction they would take in nature, changing their preferential direction at roughly <hl> the same time their wild conspecifics change course <hl>.

Caged birds display a preferential flight direction that corresponds with the migratory direction they would take in nature, changing their preferential direction at roughly <hl> the same time their wild conspecifics change course <hl> .


Question: What is it called when males return earlier to the breeding sites than females?

In polygynous species with considerable sexual dimorphism, males tend to return earlier to the breeding sites than their females. This is termed protandry.

Answer: protandry

This is termed protandry .

In polygynous species with considerable sexual dimorphism, males tend to return earlier to the breeding sites than their females. <hl> This is termed protandry . <hl>

In polygynous species with considerable sexual dimorphism, males tend to return earlier to the breeding sites than their females. This is termed <hl> protandry <hl>.


Question: What happens in polygynous species with sexual dimophism?

Answer: males tend to return earlier to the breeding sites

<hl> In polygynous species with considerable sexual dimorphism, males tend to return earlier to the breeding sites than their females. <hl> This is termed protandry.

In polygynous species with considerable sexual dimorphism, <hl> males tend to return earlier to the breeding sites <hl> than their females. This is termed protandry.


Question: Why do males in polygynous species return before the females?

Answer: sexual dimorphism

<hl> In polygynous species with considerable sexual dimorphism , males tend to return earlier to the breeding sites than their females. <hl> This is termed protandry.

In polygynous species with considerable <hl> sexual dimorphism <hl>, males tend to return earlier to the breeding sites than their females. This is termed protandry.

In polygynous species with considerable <hl> sexual dimorphism <hl> , males tend to return earlier to the breeding sites than their females.


Question: What is navigation based on?

Navigation is based on a variety of senses. Many birds have been shown to use a sun compass. Using the sun for direction involves the need for making compensation based on the time. Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), use visual landmarks as well as olfactory cues.

Answer: a variety of senses

<hl> Navigation is based on a variety of senses . <hl> Many birds have been shown to use a sun compass. Using the sun for direction involves the need for making compensation based on the time. Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), use visual landmarks as well as olfactory cues.

Navigation is based on <hl> a variety of senses <hl>. Many birds have been shown to use a sun compass. Using the sun for direction involves the need for making compensation based on the time. Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), use visual landmarks as well as olfactory cues.

Navigation is based on <hl> a variety of senses <hl> .


Question: What do many birds use as a compass?

Answer: sun

Navigation is based on a variety of senses. <hl> Many birds have been shown to use a sun compass. <hl> Using the sun for direction involves the need for making compensation based on the time. Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), use visual landmarks as well as olfactory cues.

Navigation is based on a variety of senses. Many birds have been shown to use a <hl> sun <hl> compass. Using the sun for direction involves the need for making compensation based on the time. Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), use visual landmarks as well as olfactory cues.


Question: What does using the sun for direction involve?

Answer: the need for making compensation based on the time

Navigation is based on a variety of senses. Many birds have been shown to use a sun compass. <hl> Using the sun for direction involves the need for making compensation based on the time . <hl> Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), use visual landmarks as well as olfactory cues.

Navigation is based on a variety of senses. Many birds have been shown to use a sun compass. Using the sun for direction involves <hl> the need for making compensation based on the time <hl>. Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), use visual landmarks as well as olfactory cues.

Using the sun for direction involves <hl> the need for making compensation based on the time <hl> .


Question: What else is navigation based on?

Answer: use visual landmarks

Navigation is based on a variety of senses. Many birds have been shown to use a sun compass. Using the sun for direction involves the need for making compensation based on the time. <hl> Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), use visual landmarks as well as olfactory cues. <hl>

Navigation is based on a variety of senses. Many birds have been shown to use a sun compass. Using the sun for direction involves the need for making compensation based on the time. Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), <hl> use visual landmarks <hl> as well as olfactory cues.


Question: What is magnetoception?

Answer: the ability to detect magnetic fields

Navigation is based on a variety of senses. Many birds have been shown to use a sun compass. Using the sun for direction involves the need for making compensation based on the time. <hl> Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), use visual landmarks as well as olfactory cues. <hl>

Navigation is based on a variety of senses. Many birds have been shown to use a sun compass. Using the sun for direction involves the need for making compensation based on the time. Navigation has also been shown to be based on a combination of other abilities including <hl> the ability to detect magnetic fields <hl> (magnetoception), use visual landmarks as well as olfactory cues.


Question: When do long distance migrants disperse?

Long distance migrants are believed to disperse as young birds and form attachments to potential breeding sites and to favourite wintering sites. Once the site attachment is made they show high site-fidelity, visiting the same wintering sites year after year.

Answer: as young birds

<hl> Long distance migrants are believed to disperse as young birds and form attachments to potential breeding sites and to favourite wintering sites. <hl> Once the site attachment is made they show high site-fidelity, visiting the same wintering sites year after year.

Long distance migrants are believed to disperse <hl> as young birds <hl> and form attachments to potential breeding sites and to favourite wintering sites. Once the site attachment is made they show high site-fidelity, visiting the same wintering sites year after year.


Question: What do young birds form attachments to?

Answer: potential breeding sites

<hl> Long distance migrants are believed to disperse as young birds and form attachments to potential breeding sites and to favourite wintering sites. <hl> Once the site attachment is made they show high site-fidelity, visiting the same wintering sites year after year.

Long distance migrants are believed to disperse as young birds and form attachments to <hl> potential breeding sites <hl> and to favourite wintering sites. Once the site attachment is made they show high site-fidelity, visiting the same wintering sites year after year.


Question: What else do young birds form attachments to?

Answer: wintering sites

<hl> Long distance migrants are believed to disperse as young birds and form attachments to potential breeding sites and to favourite wintering sites . <hl> Once the site attachment is made they show high site-fidelity, visiting the same wintering sites year after year.

Long distance migrants are believed to disperse as young birds and form attachments to potential breeding sites and to favourite <hl> wintering sites <hl>. Once the site attachment is made they show high site-fidelity, visiting the same wintering sites year after year.

Long distance migrants are believed to disperse as young birds and form attachments to potential breeding sites and to favourite <hl> wintering sites <hl> .


Question: What happens when the site attachment is made?

Answer: they show high site-fidelity

Long distance migrants are believed to disperse as young birds and form attachments to potential breeding sites and to favourite wintering sites. <hl> Once the site attachment is made they show high site-fidelity , visiting the same wintering sites year after year. <hl>

Long distance migrants are believed to disperse as young birds and form attachments to potential breeding sites and to favourite wintering sites. Once the site attachment is made <hl> they show high site-fidelity <hl>, visiting the same wintering sites year after year.

Once the site attachment is made <hl> they show high site-fidelity <hl> , visiting the same wintering sites year after year.


Question: Where do migrating birds visit?

Answer: the same wintering sites year after year

Long distance migrants are believed to disperse as young birds and form attachments to potential breeding sites and to favourite wintering sites. <hl> Once the site attachment is made they show high site-fidelity, visiting the same wintering sites year after year . <hl>

Long distance migrants are believed to disperse as young birds and form attachments to potential breeding sites and to favourite wintering sites. Once the site attachment is made they show high site-fidelity, visiting <hl> the same wintering sites year after year <hl>.

Once the site attachment is made they show high site-fidelity, visiting <hl> the same wintering sites year after year <hl> .


Question: What are older migrating birds better at?

The ability of birds to navigate during migrations cannot be fully explained by endogenous programming, even with the help of responses to environmental cues. The ability to successfully perform long-distance migrations can probably only be fully explained with an accounting for the cognitive ability of the birds to recognize habitats and form mental maps. Satellite tracking of day migrating raptors such as ospreys and honey buzzards has shown that older individuals are better at making corrections for wind drift.

Answer: making corrections for wind drift

The ability of birds to navigate during migrations cannot be fully explained by endogenous programming, even with the help of responses to environmental cues. The ability to successfully perform long-distance migrations can probably only be fully explained with an accounting for the cognitive ability of the birds to recognize habitats and form mental maps. <hl> Satellite tracking of day migrating raptors such as ospreys and honey buzzards has shown that older individuals are better at making corrections for wind drift . <hl>

The ability of birds to navigate during migrations cannot be fully explained by endogenous programming, even with the help of responses to environmental cues. The ability to successfully perform long-distance migrations can probably only be fully explained with an accounting for the cognitive ability of the birds to recognize habitats and form mental maps. Satellite tracking of day migrating raptors such as ospreys and honey buzzards has shown that older individuals are better at <hl> making corrections for wind drift <hl>.

Satellite tracking of day migrating raptors such as ospreys and honey buzzards has shown that older individuals are better at <hl> making corrections for wind drift <hl> .


Question: How was the migrating of ospretys and honey buzzards tracked?

Answer: Satellite

The ability of birds to navigate during migrations cannot be fully explained by endogenous programming, even with the help of responses to environmental cues. The ability to successfully perform long-distance migrations can probably only be fully explained with an accounting for the cognitive ability of the birds to recognize habitats and form mental maps. <hl> Satellite tracking of day migrating raptors such as ospreys and honey buzzards has shown that older individuals are better at making corrections for wind drift. <hl>

The ability of birds to navigate during migrations cannot be fully explained by endogenous programming, even with the help of responses to environmental cues. The ability to successfully perform long-distance migrations can probably only be fully explained with an accounting for the cognitive ability of the birds to recognize habitats and form mental maps. <hl> Satellite <hl> tracking of day migrating raptors such as ospreys and honey buzzards has shown that older individuals are better at making corrections for wind drift.


Question: What do the birds do to successfully perform long distance migration?

Answer: recognize habitats and form mental maps

The ability of birds to navigate during migrations cannot be fully explained by endogenous programming, even with the help of responses to environmental cues. <hl> The ability to successfully perform long-distance migrations can probably only be fully explained with an accounting for the cognitive ability of the birds to recognize habitats and form mental maps . <hl> Satellite tracking of day migrating raptors such as ospreys and honey buzzards has shown that older individuals are better at making corrections for wind drift.

The ability of birds to navigate during migrations cannot be fully explained by endogenous programming, even with the help of responses to environmental cues. The ability to successfully perform long-distance migrations can probably only be fully explained with an accounting for the cognitive ability of the birds to <hl> recognize habitats and form mental maps <hl>. Satellite tracking of day migrating raptors such as ospreys and honey buzzards has shown that older individuals are better at making corrections for wind drift.

The ability to successfully perform long-distance migrations can probably only be fully explained with an accounting for the cognitive ability of the birds to <hl> recognize habitats and form mental maps <hl> .


Question: What are examples of day migrating raptors?

Answer: ospreys and honey buzzards

The ability of birds to navigate during migrations cannot be fully explained by endogenous programming, even with the help of responses to environmental cues. The ability to successfully perform long-distance migrations can probably only be fully explained with an accounting for the cognitive ability of the birds to recognize habitats and form mental maps. <hl> Satellite tracking of day migrating raptors such as ospreys and honey buzzards has shown that older individuals are better at making corrections for wind drift. <hl>

The ability of birds to navigate during migrations cannot be fully explained by endogenous programming, even with the help of responses to environmental cues. The ability to successfully perform long-distance migrations can probably only be fully explained with an accounting for the cognitive ability of the birds to recognize habitats and form mental maps. Satellite tracking of day migrating raptors such as <hl> ospreys and honey buzzards <hl> has shown that older individuals are better at making corrections for wind drift.


Question: What two electromagnetic tools do birds use to find their destinations?

Migratory birds may use two electromagnetic tools to find their destinations: one that is entirely innate and another that relies on experience. A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. At this stage the bird is in the position of a boy scout with a compass but no map, until it grows accustomed to the journey and can put its other capabilities to use. With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and let it know when it has reached its destination. There is a neural connection between the eye and "Cluster N", the part of the forebrain that is active during migrational orientation, suggesting that birds may actually be able to see the magnetic field of the earth.

Answer: one that is entirely innate and another that relies on experience

<hl> Migratory birds may use two electromagnetic tools to find their destinations: one that is entirely innate and another that relies on experience . <hl> A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. At this stage the bird is in the position of a boy scout with a compass but no map, until it grows accustomed to the journey and can put its other capabilities to use. With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and let it know when it has reached its destination. There is a neural connection between the eye and "Cluster N", the part of the forebrain that is active during migrational orientation, suggesting that birds may actually be able to see the magnetic field of the earth.

Migratory birds may use two electromagnetic tools to find their destinations: <hl> one that is entirely innate and another that relies on experience <hl>. A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. At this stage the bird is in the position of a boy scout with a compass but no map, until it grows accustomed to the journey and can put its other capabilities to use. With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and let it know when it has reached its destination. There is a neural connection between the eye and "Cluster N", the part of the forebrain that is active during migrational orientation, suggesting that birds may actually be able to see the magnetic field of the earth.

Migratory birds may use two electromagnetic tools to find their destinations: <hl> one that is entirely innate and another that relies on experience <hl> .


Question: Where is the neural connection that is active during migration located?

Answer: between the eye and "Cluster N"

Migratory birds may use two electromagnetic tools to find their destinations: one that is entirely innate and another that relies on experience. A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. At this stage the bird is in the position of a boy scout with a compass but no map, until it grows accustomed to the journey and can put its other capabilities to use. With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and let it know when it has reached its destination. <hl> There is a neural connection between the eye and "Cluster N" , the part of the forebrain that is active during migrational orientation, suggesting that birds may actually be able to see the magnetic field of the earth. <hl>

Migratory birds may use two electromagnetic tools to find their destinations: one that is entirely innate and another that relies on experience. A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. At this stage the bird is in the position of a boy scout with a compass but no map, until it grows accustomed to the journey and can put its other capabilities to use. With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and let it know when it has reached its destination. There is a neural connection <hl> between the eye and "Cluster N" <hl>, the part of the forebrain that is active during migrational orientation, suggesting that birds may actually be able to see the magnetic field of the earth.

There is a neural connection <hl> between the eye and "Cluster N" <hl> , the part of the forebrain that is active during migrational orientation, suggesting that birds may actually be able to see the magnetic field of the earth.


Question: What is Cluster N?

Answer: the part of the forebrain that is active during migrational orientation

Migratory birds may use two electromagnetic tools to find their destinations: one that is entirely innate and another that relies on experience. A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. At this stage the bird is in the position of a boy scout with a compass but no map, until it grows accustomed to the journey and can put its other capabilities to use. With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and let it know when it has reached its destination. <hl> There is a neural connection between the eye and "Cluster N", the part of the forebrain that is active during migrational orientation , suggesting that birds may actually be able to see the magnetic field of the earth. <hl>

Migratory birds may use two electromagnetic tools to find their destinations: one that is entirely innate and another that relies on experience. A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. At this stage the bird is in the position of a boy scout with a compass but no map, until it grows accustomed to the journey and can put its other capabilities to use. With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and let it know when it has reached its destination. There is a neural connection between the eye and "Cluster N", <hl> the part of the forebrain that is active during migrational orientation <hl>, suggesting that birds may actually be able to see the magnetic field of the earth.

There is a neural connection between the eye and "Cluster N", <hl> the part of the forebrain that is active during migrational orientation <hl> , suggesting that birds may actually be able to see the magnetic field of the earth.


Question: What is a young bird on it's first migration compared to?

Answer: a boy scout with a compass but no map

Migratory birds may use two electromagnetic tools to find their destinations: one that is entirely innate and another that relies on experience. A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. <hl> At this stage the bird is in the position of a boy scout with a compass but no map , until it grows accustomed to the journey and can put its other capabilities to use. <hl> With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and let it know when it has reached its destination. There is a neural connection between the eye and "Cluster N", the part of the forebrain that is active during migrational orientation, suggesting that birds may actually be able to see the magnetic field of the earth.

Migratory birds may use two electromagnetic tools to find their destinations: one that is entirely innate and another that relies on experience. A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. At this stage the bird is in the position of <hl> a boy scout with a compass but no map <hl>, until it grows accustomed to the journey and can put its other capabilities to use. With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and let it know when it has reached its destination. There is a neural connection between the eye and "Cluster N", the part of the forebrain that is active during migrational orientation, suggesting that birds may actually be able to see the magnetic field of the earth.

At this stage the bird is in the position of <hl> a boy scout with a compass but no map <hl> , until it grows accustomed to the journey and can put its other capabilities to use.


Question: How does the magnetic field help the bird at different latitudes?

Answer: let it know when it has reached its destination

Migratory birds may use two electromagnetic tools to find their destinations: one that is entirely innate and another that relies on experience. A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. At this stage the bird is in the position of a boy scout with a compass but no map, until it grows accustomed to the journey and can put its other capabilities to use. With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. <hl> Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and let it know when it has reached its destination . <hl> There is a neural connection between the eye and "Cluster N", the part of the forebrain that is active during migrational orientation, suggesting that birds may actually be able to see the magnetic field of the earth.

Migratory birds may use two electromagnetic tools to find their destinations: one that is entirely innate and another that relies on experience. A young bird on its first migration flies in the correct direction according to the Earth's magnetic field, but does not know how far the journey will be. It does this through a radical pair mechanism whereby chemical reactions in special photo pigments sensitive to long wavelengths are affected by the field. Although this only works during daylight hours, it does not use the position of the sun in any way. At this stage the bird is in the position of a boy scout with a compass but no map, until it grows accustomed to the journey and can put its other capabilities to use. With experience it learns various landmarks and this "mapping" is done by magnetites in the trigeminal system, which tell the bird how strong the field is. Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and <hl> let it know when it has reached its destination <hl>. There is a neural connection between the eye and "Cluster N", the part of the forebrain that is active during migrational orientation, suggesting that birds may actually be able to see the magnetic field of the earth.

Because birds migrate between northern and southern regions, the magnetic field strengths at different latitudes let it interpret the radical pair mechanism more accurately and <hl> let it know when it has reached its destination <hl> .


Question: How can migrating birds lose their way?

Migrating birds can lose their way and appear outside their normal ranges. This can be due to flying past their destinations as in the "spring overshoot" in which birds returning to their breeding areas overshoot and end up further north than intended. Certain areas, because of their location, have become famous as watchpoints for such birds. Examples are the Point Pelee National Park in Canada, and Spurn in England.

Answer: flying past their destinations

Migrating birds can lose their way and appear outside their normal ranges. <hl> This can be due to flying past their destinations as in the "spring overshoot" in which birds returning to their breeding areas overshoot and end up further north than intended. <hl> Certain areas, because of their location, have become famous as watchpoints for such birds. Examples are the Point Pelee National Park in Canada, and Spurn in England.

Migrating birds can lose their way and appear outside their normal ranges. This can be due to <hl> flying past their destinations <hl> as in the "spring overshoot" in which birds returning to their breeding areas overshoot and end up further north than intended. Certain areas, because of their location, have become famous as watchpoints for such birds. Examples are the Point Pelee National Park in Canada, and Spurn in England.


Question: What is flying past their destinations called?

Answer: spring overshoot

Migrating birds can lose their way and appear outside their normal ranges. <hl> This can be due to flying past their destinations as in the " spring overshoot " in which birds returning to their breeding areas overshoot and end up further north than intended. <hl> Certain areas, because of their location, have become famous as watchpoints for such birds. Examples are the Point Pelee National Park in Canada, and Spurn in England.

Migrating birds can lose their way and appear outside their normal ranges. This can be due to flying past their destinations as in the "<hl> spring overshoot <hl>" in which birds returning to their breeding areas overshoot and end up further north than intended. Certain areas, because of their location, have become famous as watchpoints for such birds. Examples are the Point Pelee National Park in Canada, and Spurn in England.

This can be due to flying past their destinations as in the " <hl> spring overshoot <hl> " in which birds returning to their breeding areas overshoot and end up further north than intended.


Question: What location has become famous for bird overshooters?

Answer: Point Pelee National Park

Migrating birds can lose their way and appear outside their normal ranges. This can be due to flying past their destinations as in the "spring overshoot" in which birds returning to their breeding areas overshoot and end up further north than intended. Certain areas, because of their location, have become famous as watchpoints for such birds. <hl> Examples are the Point Pelee National Park in Canada, and Spurn in England. <hl>

Migrating birds can lose their way and appear outside their normal ranges. This can be due to flying past their destinations as in the "spring overshoot" in which birds returning to their breeding areas overshoot and end up further north than intended. Certain areas, because of their location, have become famous as watchpoints for such birds. Examples are the <hl> Point Pelee National Park <hl> in Canada, and Spurn in England.


Question: What other location is famous for spring overshoot?

Answer: Spurn in England

Migrating birds can lose their way and appear outside their normal ranges. This can be due to flying past their destinations as in the "spring overshoot" in which birds returning to their breeding areas overshoot and end up further north than intended. Certain areas, because of their location, have become famous as watchpoints for such birds. <hl> Examples are the Point Pelee National Park in Canada, and Spurn in England . <hl>

Migrating birds can lose their way and appear outside their normal ranges. This can be due to flying past their destinations as in the "spring overshoot" in which birds returning to their breeding areas overshoot and end up further north than intended. Certain areas, because of their location, have become famous as watchpoints for such birds. Examples are the Point Pelee National Park in Canada, and <hl> Spurn in England <hl>.

Examples are the Point Pelee National Park in Canada, and <hl> Spurn in England <hl> .


Question: Where do bird overshooters end up?

Answer: further north than intended

Migrating birds can lose their way and appear outside their normal ranges. <hl> This can be due to flying past their destinations as in the "spring overshoot" in which birds returning to their breeding areas overshoot and end up further north than intended . <hl> Certain areas, because of their location, have become famous as watchpoints for such birds. Examples are the Point Pelee National Park in Canada, and Spurn in England.

Migrating birds can lose their way and appear outside their normal ranges. This can be due to flying past their destinations as in the "spring overshoot" in which birds returning to their breeding areas overshoot and end up <hl> further north than intended <hl>. Certain areas, because of their location, have become famous as watchpoints for such birds. Examples are the Point Pelee National Park in Canada, and Spurn in England.

This can be due to flying past their destinations as in the "spring overshoot" in which birds returning to their breeding areas overshoot and end up <hl> further north than intended <hl> .


Question: What is it called when the genetic programing of young birds fail?

Reverse migration, where the genetic programming of young birds fails to work properly, can lead to rarities turning up as vagrants thousands of kilometres out of range.

Answer: Reverse migration

<hl> Reverse migration , where the genetic programming of young birds fails to work properly, can lead to rarities turning up as vagrants thousands of kilometres out of range. <hl>

<hl> Reverse migration <hl>, where the genetic programming of young birds fails to work properly, can lead to rarities turning up as vagrants thousands of kilometres out of range.

<hl> Reverse migration <hl> , where the genetic programming of young birds fails to work properly, can lead to rarities turning up as vagrants thousands of kilometres out of range.


Question: What is reverse migration?

Answer: where the genetic programming of young birds fails to work properly

<hl> Reverse migration, where the genetic programming of young birds fails to work properly , can lead to rarities turning up as vagrants thousands of kilometres out of range. <hl>

Reverse migration, <hl> where the genetic programming of young birds fails to work properly <hl>, can lead to rarities turning up as vagrants thousands of kilometres out of range.

Reverse migration, <hl> where the genetic programming of young birds fails to work properly <hl> , can lead to rarities turning up as vagrants thousands of kilometres out of range.


Question: What does reverse migration lead to?

Answer: rarities turning up as vagrants thousands of kilometres out of range

<hl> Reverse migration, where the genetic programming of young birds fails to work properly, can lead to rarities turning up as vagrants thousands of kilometres out of range . <hl>

Reverse migration, where the genetic programming of young birds fails to work properly, can lead to <hl> rarities turning up as vagrants thousands of kilometres out of range <hl>.

Reverse migration, where the genetic programming of young birds fails to work properly, can lead to <hl> rarities turning up as vagrants thousands of kilometres out of range <hl> .


Question: How far out of range can rarities get?

Answer: thousands of kilometres

<hl> Reverse migration, where the genetic programming of young birds fails to work properly, can lead to rarities turning up as vagrants thousands of kilometres out of range. <hl>

Reverse migration, where the genetic programming of young birds fails to work properly, can lead to rarities turning up as vagrants <hl> thousands of kilometres <hl> out of range.


Question: What is it called when birds from one region join birds from a different region?

A related phenomenon called "abmigration" involves birds from one region joining similar birds from a different breeding region in the common winter grounds and then migrating back along with the new population. This is especially common in some waterfowl, which shift from one flyway to another.

Answer: abmigration

<hl> A related phenomenon called " abmigration " involves birds from one region joining similar birds from a different breeding region in the common winter grounds and then migrating back along with the new population. <hl> This is especially common in some waterfowl, which shift from one flyway to another.

A related phenomenon called "<hl> abmigration <hl>" involves birds from one region joining similar birds from a different breeding region in the common winter grounds and then migrating back along with the new population. This is especially common in some waterfowl, which shift from one flyway to another.

A related phenomenon called " <hl> abmigration <hl> " involves birds from one region joining similar birds from a different breeding region in the common winter grounds and then migrating back along with the new population.


Question: What kind of bird is most likely to abmigrate?

Answer: waterfowl

A related phenomenon called "abmigration" involves birds from one region joining similar birds from a different breeding region in the common winter grounds and then migrating back along with the new population. <hl> This is especially common in some waterfowl , which shift from one flyway to another. <hl>

A related phenomenon called "abmigration" involves birds from one region joining similar birds from a different breeding region in the common winter grounds and then migrating back along with the new population. This is especially common in some <hl> waterfowl <hl>, which shift from one flyway to another.

This is especially common in some <hl> waterfowl <hl> , which shift from one flyway to another.


Question: Who do abmigrating birds return with?

Answer: the new population

<hl> A related phenomenon called "abmigration" involves birds from one region joining similar birds from a different breeding region in the common winter grounds and then migrating back along with the new population . <hl> This is especially common in some waterfowl, which shift from one flyway to another.

A related phenomenon called "abmigration" involves birds from one region joining similar birds from a different breeding region in the common winter grounds and then migrating back along with <hl> the new population <hl>. This is especially common in some waterfowl, which shift from one flyway to another.

A related phenomenon called "abmigration" involves birds from one region joining similar birds from a different breeding region in the common winter grounds and then migrating back along with <hl> the new population <hl> .


Question: What is a re-introduction scheme?

It has been possible to teach a migration route to a flock of birds, for example in re-introduction schemes. After a trial with Canada geese Branta canadensis, microlight aircraft were used in the US to teach safe migration routes to reintroduced whooping cranes Grus americana.

Answer: to teach a migration route to a flock of birds

<hl> It has been possible to teach a migration route to a flock of birds , for example in re-introduction schemes. <hl> After a trial with Canada geese Branta canadensis, microlight aircraft were used in the US to teach safe migration routes to reintroduced whooping cranes Grus americana.

It has been possible <hl> to teach a migration route to a flock of birds <hl>, for example in re-introduction schemes. After a trial with Canada geese Branta canadensis, microlight aircraft were used in the US to teach safe migration routes to reintroduced whooping cranes Grus americana.

It has been possible <hl> to teach a migration route to a flock of birds <hl> , for example in re-introduction schemes.


Question: What did they use to teach birds a migration route?

Answer: microlight aircraft

It has been possible to teach a migration route to a flock of birds, for example in re-introduction schemes. <hl> After a trial with Canada geese Branta canadensis, microlight aircraft were used in the US to teach safe migration routes to reintroduced whooping cranes Grus americana. <hl>

It has been possible to teach a migration route to a flock of birds, for example in re-introduction schemes. After a trial with Canada geese Branta canadensis, <hl> microlight aircraft <hl> were used in the US to teach safe migration routes to reintroduced whooping cranes Grus americana.


Question: Which birds did they reintroduce to the US?

Answer: whooping cranes

It has been possible to teach a migration route to a flock of birds, for example in re-introduction schemes. <hl> After a trial with Canada geese Branta canadensis, microlight aircraft were used in the US to teach safe migration routes to reintroduced whooping cranes Grus americana. <hl>

It has been possible to teach a migration route to a flock of birds, for example in re-introduction schemes. After a trial with Canada geese Branta canadensis, microlight aircraft were used in the US to teach safe migration routes to reintroduced <hl> whooping cranes <hl> Grus americana.


Question: Which birds did they use as a trial run?

Answer: Canada geese

It has been possible to teach a migration route to a flock of birds, for example in re-introduction schemes. <hl> After a trial with Canada geese Branta canadensis, microlight aircraft were used in the US to teach safe migration routes to reintroduced whooping cranes Grus americana. <hl>

It has been possible to teach a migration route to a flock of birds, for example in re-introduction schemes. After a trial with <hl> Canada geese <hl> Branta canadensis, microlight aircraft were used in the US to teach safe migration routes to reintroduced whooping cranes Grus americana.


Question: What do birds need to change to meet the demands of migration?

Birds need to alter their metabolism in order to meet the demands of migration. The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. The timing of this molt - usually once a year but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.

Answer: their metabolism

<hl> Birds need to alter their metabolism in order to meet the demands of migration. <hl> The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. The timing of this molt - usually once a year but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.

Birds need to alter <hl> their metabolism <hl> in order to meet the demands of migration. The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. The timing of this molt - usually once a year but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.


Question: How often do birds molt?

Answer: usually once a year

Birds need to alter their metabolism in order to meet the demands of migration. The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. <hl> The timing of this molt - usually once a year but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. <hl> Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.

Birds need to alter their metabolism in order to meet the demands of migration. The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. The timing of this molt - <hl> usually once a year <hl> but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.


Question: How do birds store energy?

Answer: through the accumulation of fat and the control of sleep

Birds need to alter their metabolism in order to meet the demands of migration. <hl> The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. <hl> In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. The timing of this molt - usually once a year but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.

Birds need to alter their metabolism in order to meet the demands of migration. The storage of energy <hl> through the accumulation of fat and the control of sleep <hl> in nocturnal migrants require special physiological adaptations. In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. The timing of this molt - usually once a year but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.


Question: Why do birds need to molt?

Answer: feathers of a bird suffer from wear-and-tear

Birds need to alter their metabolism in order to meet the demands of migration. The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. <hl> In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. <hl> The timing of this molt - usually once a year but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.

Birds need to alter their metabolism in order to meet the demands of migration. The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. In addition, the <hl> feathers of a bird suffer from wear-and-tear <hl> and require to be molted. The timing of this molt - usually once a year but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.


Question: When do birds molt?

Answer: varies with some species

Birds need to alter their metabolism in order to meet the demands of migration. The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. <hl> The timing of this molt - usually once a year but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. <hl> Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.

Birds need to alter their metabolism in order to meet the demands of migration. The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. The timing of this molt - usually once a year but sometimes twice - <hl> varies with some species <hl> molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.


Question: How was migration developed?

Migration in birds is highly labile and is believed to have developed independently in many avian lineages. While it is agreed that the behavioral and physiological adaptations necessary for migration are under genetic control, some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the genetic framework for migratory behavior exists in nearly all avian lineages. This explains the rapid appearance of migratory behavior after the most recent glacial maximum.

Answer: independently

<hl> Migration in birds is highly labile and is believed to have developed independently in many avian lineages. <hl> While it is agreed that the behavioral and physiological adaptations necessary for migration are under genetic control, some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the genetic framework for migratory behavior exists in nearly all avian lineages. This explains the rapid appearance of migratory behavior after the most recent glacial maximum.

Migration in birds is highly labile and is believed to have developed <hl> independently <hl> in many avian lineages. While it is agreed that the behavioral and physiological adaptations necessary for migration are under genetic control, some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the genetic framework for migratory behavior exists in nearly all avian lineages. This explains the rapid appearance of migratory behavior after the most recent glacial maximum.


Question: What is highly labile?

Answer: Migration in birds

<hl> Migration in birds is highly labile and is believed to have developed independently in many avian lineages. <hl> While it is agreed that the behavioral and physiological adaptations necessary for migration are under genetic control, some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the genetic framework for migratory behavior exists in nearly all avian lineages. This explains the rapid appearance of migratory behavior after the most recent glacial maximum.

<hl> Migration in birds <hl> is highly labile and is believed to have developed independently in many avian lineages. While it is agreed that the behavioral and physiological adaptations necessary for migration are under genetic control, some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the genetic framework for migratory behavior exists in nearly all avian lineages. This explains the rapid appearance of migratory behavior after the most recent glacial maximum.


Question: What causes the behavioral adaptations necessary for migration?

Answer: genetic control

Migration in birds is highly labile and is believed to have developed independently in many avian lineages. <hl> While it is agreed that the behavioral and physiological adaptations necessary for migration are under genetic control , some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the genetic framework for migratory behavior exists in nearly all avian lineages. <hl> This explains the rapid appearance of migratory behavior after the most recent glacial maximum.

Migration in birds is highly labile and is believed to have developed independently in many avian lineages. While it is agreed that the behavioral and physiological adaptations necessary for migration are under <hl> genetic control <hl>, some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the genetic framework for migratory behavior exists in nearly all avian lineages. This explains the rapid appearance of migratory behavior after the most recent glacial maximum.

While it is agreed that the behavioral and physiological adaptations necessary for migration are under <hl> genetic control <hl> , some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the genetic framework for migratory behavior exists in nearly all avian lineages.


Question: What exists in nearly all avian lineages?

Answer: genetic framework for migratory behavior

Migration in birds is highly labile and is believed to have developed independently in many avian lineages. <hl> While it is agreed that the behavioral and physiological adaptations necessary for migration are under genetic control, some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the genetic framework for migratory behavior exists in nearly all avian lineages. <hl> This explains the rapid appearance of migratory behavior after the most recent glacial maximum.

Migration in birds is highly labile and is believed to have developed independently in many avian lineages. While it is agreed that the behavioral and physiological adaptations necessary for migration are under genetic control, some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the <hl> genetic framework for migratory behavior <hl> exists in nearly all avian lineages. This explains the rapid appearance of migratory behavior after the most recent glacial maximum.


Question: What percentage increase in flight distance will often be adaptive?

Theoretical analyses show that detours that increase flight distance by up to 20% will often be adaptive on aerodynamic grounds - a bird that loads itself with food to cross a long barrier flies less efficiently. However some species show circuitous migratory routes that reflect historical range expansions and are far from optimal in ecological terms. An example is the migration of continental populations of Swainson's thrush Catharus ustulatus, which fly far east across North America before turning south via Florida to reach northern South America; this route is believed to be the consequence of a range expansion that occurred about 10,000 years ago. Detours may also be caused by differential wind conditions, predation risk, or other factors.

Answer: 20%

<hl> Theoretical analyses show that detours that increase flight distance by up to 20% will often be adaptive on aerodynamic grounds - a bird that loads itself with food to cross a long barrier flies less efficiently. <hl> However some species show circuitous migratory routes that reflect historical range expansions and are far from optimal in ecological terms. An example is the migration of continental populations of Swainson's thrush Catharus ustulatus, which fly far east across North America before turning south via Florida to reach northern South America; this route is believed to be the consequence of a range expansion that occurred about 10,000 years ago. Detours may also be caused by differential wind conditions, predation risk, or other factors.

Theoretical analyses show that detours that increase flight distance by up to <hl> 20% <hl> will often be adaptive on aerodynamic grounds - a bird that loads itself with food to cross a long barrier flies less efficiently. However some species show circuitous migratory routes that reflect historical range expansions and are far from optimal in ecological terms. An example is the migration of continental populations of Swainson's thrush Catharus ustulatus, which fly far east across North America before turning south via Florida to reach northern South America; this route is believed to be the consequence of a range expansion that occurred about 10,000 years ago. Detours may also be caused by differential wind conditions, predation risk, or other factors.


Question: What kind of bird flies less efficiently?

Answer: a bird that loads itself with food

<hl> Theoretical analyses show that detours that increase flight distance by up to 20% will often be adaptive on aerodynamic grounds - a bird that loads itself with food to cross a long barrier flies less efficiently. <hl> However some species show circuitous migratory routes that reflect historical range expansions and are far from optimal in ecological terms. An example is the migration of continental populations of Swainson's thrush Catharus ustulatus, which fly far east across North America before turning south via Florida to reach northern South America; this route is believed to be the consequence of a range expansion that occurred about 10,000 years ago. Detours may also be caused by differential wind conditions, predation risk, or other factors.

Theoretical analyses show that detours that increase flight distance by up to 20% will often be adaptive on aerodynamic grounds - <hl> a bird that loads itself with food <hl> to cross a long barrier flies less efficiently. However some species show circuitous migratory routes that reflect historical range expansions and are far from optimal in ecological terms. An example is the migration of continental populations of Swainson's thrush Catharus ustulatus, which fly far east across North America before turning south via Florida to reach northern South America; this route is believed to be the consequence of a range expansion that occurred about 10,000 years ago. Detours may also be caused by differential wind conditions, predation risk, or other factors.


Question: What type of bird show circuitous migratory routes?

Answer: Swainson's thrush

Theoretical analyses show that detours that increase flight distance by up to 20% will often be adaptive on aerodynamic grounds - a bird that loads itself with food to cross a long barrier flies less efficiently. However some species show circuitous migratory routes that reflect historical range expansions and are far from optimal in ecological terms. <hl> An example is the migration of continental populations of Swainson's thrush Catharus ustulatus, which fly far east across North America before turning south via Florida to reach northern South America; this route is believed to be the consequence of a range expansion that occurred about 10,000 years ago. <hl> Detours may also be caused by differential wind conditions, predation risk, or other factors.

Theoretical analyses show that detours that increase flight distance by up to 20% will often be adaptive on aerodynamic grounds - a bird that loads itself with food to cross a long barrier flies less efficiently. However some species show circuitous migratory routes that reflect historical range expansions and are far from optimal in ecological terms. An example is the migration of continental populations of <hl> Swainson's thrush <hl> Catharus ustulatus, which fly far east across North America before turning south via Florida to reach northern South America; this route is believed to be the consequence of a range expansion that occurred about 10,000 years ago. Detours may also be caused by differential wind conditions, predation risk, or other factors.


Question: Where do Swainson's thrush fly from?

Answer: far east across North America

Theoretical analyses show that detours that increase flight distance by up to 20% will often be adaptive on aerodynamic grounds - a bird that loads itself with food to cross a long barrier flies less efficiently. However some species show circuitous migratory routes that reflect historical range expansions and are far from optimal in ecological terms. <hl> An example is the migration of continental populations of Swainson's thrush Catharus ustulatus, which fly far east across North America before turning south via Florida to reach northern South America; this route is believed to be the consequence of a range expansion that occurred about 10,000 years ago. <hl> Detours may also be caused by differential wind conditions, predation risk, or other factors.

Theoretical analyses show that detours that increase flight distance by up to 20% will often be adaptive on aerodynamic grounds - a bird that loads itself with food to cross a long barrier flies less efficiently. However some species show circuitous migratory routes that reflect historical range expansions and are far from optimal in ecological terms. An example is the migration of continental populations of Swainson's thrush Catharus ustulatus, which fly <hl> far east across North America <hl> before turning south via Florida to reach northern South America; this route is believed to be the consequence of a range expansion that occurred about 10,000 years ago. Detours may also be caused by differential wind conditions, predation risk, or other factors.


Question: What is expected to have an effect on migration timing?

Large scale climatic changes, as have been experienced in the past, are expected to have an effect on the timing of migration. Studies have shown a variety of effects including timing changes in migration, breeding as well as population variations.

Answer: climatic changes

<hl> Large scale climatic changes , as have been experienced in the past, are expected to have an effect on the timing of migration. <hl> Studies have shown a variety of effects including timing changes in migration, breeding as well as population variations.

Large scale <hl> climatic changes <hl>, as have been experienced in the past, are expected to have an effect on the timing of migration. Studies have shown a variety of effects including timing changes in migration, breeding as well as population variations.

Large scale <hl> climatic changes <hl> , as have been experienced in the past, are expected to have an effect on the timing of migration.


Question: What have studies shown regarding climate change?

Answer: timing changes in migration

Large scale climatic changes, as have been experienced in the past, are expected to have an effect on the timing of migration. <hl> Studies have shown a variety of effects including timing changes in migration , breeding as well as population variations. <hl>

Large scale climatic changes, as have been experienced in the past, are expected to have an effect on the timing of migration. Studies have shown a variety of effects including <hl> timing changes in migration <hl>, breeding as well as population variations.

Studies have shown a variety of effects including <hl> timing changes in migration <hl> , breeding as well as population variations.


Question: What else is climate change been shown to change?

Answer: breeding as well as population variations

Large scale climatic changes, as have been experienced in the past, are expected to have an effect on the timing of migration. <hl> Studies have shown a variety of effects including timing changes in migration, breeding as well as population variations . <hl>

Large scale climatic changes, as have been experienced in the past, are expected to have an effect on the timing of migration. Studies have shown a variety of effects including timing changes in migration, <hl> breeding as well as population variations <hl>.

Studies have shown a variety of effects including timing changes in migration, <hl> breeding as well as population variations <hl> .


Question: What other species does migration help?

The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice, which in turn may carry micro-organisms including those of concern to human health. Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. Birds may also have a role in the dispersal of propagules of plants and plankton.

Answer: ectoparasites such as ticks and lice

<hl> The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice , which in turn may carry micro-organisms including those of concern to human health. <hl> Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. Birds may also have a role in the dispersal of propagules of plants and plankton.

The migration of birds also aids the movement of other species, including those of <hl> ectoparasites such as ticks and lice <hl>, which in turn may carry micro-organisms including those of concern to human health. Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. Birds may also have a role in the dispersal of propagules of plants and plankton.

The migration of birds also aids the movement of other species, including those of <hl> ectoparasites such as ticks and lice <hl> , which in turn may carry micro-organisms including those of concern to human health.


Question: What is a greater threat of disease transmission?

Answer: import of pet and domestic birds

The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice, which in turn may carry micro-organisms including those of concern to human health. <hl> Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. <hl> Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. Birds may also have a role in the dispersal of propagules of plants and plankton.

The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice, which in turn may carry micro-organisms including those of concern to human health. Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; <hl> import of pet and domestic birds <hl> is a greater threat. Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. Birds may also have a role in the dispersal of propagules of plants and plankton.


Question: What has been studied as a mechanism of disease transmission?

Answer: bird migration

The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice, which in turn may carry micro-organisms including those of concern to human health. <hl> Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. <hl> Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. Birds may also have a role in the dispersal of propagules of plants and plankton.

The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice, which in turn may carry micro-organisms including those of concern to human health. Due to the global spread of avian influenza, <hl> bird migration <hl> has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. Birds may also have a role in the dispersal of propagules of plants and plankton.


Question: What has a role in the dispersal of propagules of plants and plankton?

Answer: Birds

The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice, which in turn may carry micro-organisms including those of concern to human health. Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. <hl> Birds may also have a role in the dispersal of propagules of plants and plankton. <hl>

The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice, which in turn may carry micro-organisms including those of concern to human health. Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. <hl> Birds <hl> may also have a role in the dispersal of propagules of plants and plankton.


Question: What virus is maintained in birds without lethal effects?

Answer: West Nile Virus

The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice, which in turn may carry micro-organisms including those of concern to human health. Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. <hl> Some viruses that are maintained in birds without lethal effects, such as the West Nile Virus may however be spread by migrating birds. <hl> Birds may also have a role in the dispersal of propagules of plants and plankton.

The migration of birds also aids the movement of other species, including those of ectoparasites such as ticks and lice, which in turn may carry micro-organisms including those of concern to human health. Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat. Some viruses that are maintained in birds without lethal effects, such as the <hl> West Nile Virus <hl> may however be spread by migrating birds. Birds may also have a role in the dispersal of propagules of plants and plankton.


Question: Who takes advantage of migrating birds?

Some predators take advantage of the concentration of birds during migration. Greater noctule bats feed on nocturnal migrating passerines. Some birds of prey specialize on migrating waders.

Answer: Greater noctule bats

Some predators take advantage of the concentration of birds during migration. <hl> Greater noctule bats feed on nocturnal migrating passerines. <hl> Some birds of prey specialize on migrating waders.

Some predators take advantage of the concentration of birds during migration. <hl> Greater noctule bats <hl> feed on nocturnal migrating passerines. Some birds of prey specialize on migrating waders.


Question: What do greater noctule bats feed on?

Answer: nocturnal migrating passerines

Some predators take advantage of the concentration of birds during migration. <hl> Greater noctule bats feed on nocturnal migrating passerines . <hl> Some birds of prey specialize on migrating waders.

Some predators take advantage of the concentration of birds during migration. Greater noctule bats feed on <hl> nocturnal migrating passerines <hl>. Some birds of prey specialize on migrating waders.

Greater noctule bats feed on <hl> nocturnal migrating passerines <hl> .


Question: What do some birds of prey specialize on?

Answer: migrating waders

Some predators take advantage of the concentration of birds during migration. Greater noctule bats feed on nocturnal migrating passerines. <hl> Some birds of prey specialize on migrating waders . <hl>

Some predators take advantage of the concentration of birds during migration. Greater noctule bats feed on nocturnal migrating passerines. Some birds of prey specialize on <hl> migrating waders <hl>.

Some birds of prey specialize on <hl> migrating waders <hl> .


Question: What is the oldest way to study migration?

Bird migration routes have been studied by a variety of techniques including the oldest, marking. Swans have been marked with a nick on the beak since about 1560 in England. Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. Other techniques include radar and satellite tracking.

Answer: marking

<hl> Bird migration routes have been studied by a variety of techniques including the oldest, marking . <hl> Swans have been marked with a nick on the beak since about 1560 in England. Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. Other techniques include radar and satellite tracking.

Bird migration routes have been studied by a variety of techniques including the oldest, <hl> marking <hl>. Swans have been marked with a nick on the beak since about 1560 in England. Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. Other techniques include radar and satellite tracking.

Bird migration routes have been studied by a variety of techniques including the oldest, <hl> marking <hl> .


Question: How have swans been marked?

Answer: a nick on the beak

Bird migration routes have been studied by a variety of techniques including the oldest, marking. <hl> Swans have been marked with a nick on the beak since about 1560 in England. <hl> Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. Other techniques include radar and satellite tracking.

Bird migration routes have been studied by a variety of techniques including the oldest, marking. Swans have been marked with <hl> a nick on the beak <hl> since about 1560 in England. Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. Other techniques include radar and satellite tracking.


Question: Who was scientific ringing pioneered by?

Answer: Hans Christian Cornelius Mortensen

Bird migration routes have been studied by a variety of techniques including the oldest, marking. Swans have been marked with a nick on the beak since about 1560 in England. <hl> Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. <hl> Other techniques include radar and satellite tracking.

Bird migration routes have been studied by a variety of techniques including the oldest, marking. Swans have been marked with a nick on the beak since about 1560 in England. Scientific ringing was pioneered by <hl> Hans Christian Cornelius Mortensen <hl> in 1899. Other techniques include radar and satellite tracking.


Question: Since when have swans been marked?

Answer: 1560

Bird migration routes have been studied by a variety of techniques including the oldest, marking. <hl> Swans have been marked with a nick on the beak since about 1560 in England. <hl> Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. Other techniques include radar and satellite tracking.

Bird migration routes have been studied by a variety of techniques including the oldest, marking. Swans have been marked with a nick on the beak since about <hl> 1560 <hl> in England. Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. Other techniques include radar and satellite tracking.


Question: What are other forms of studying migration?

Answer: radar and satellite tracking

Bird migration routes have been studied by a variety of techniques including the oldest, marking. Swans have been marked with a nick on the beak since about 1560 in England. Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. <hl> Other techniques include radar and satellite tracking . <hl>

Bird migration routes have been studied by a variety of techniques including the oldest, marking. Swans have been marked with a nick on the beak since about 1560 in England. Scientific ringing was pioneered by Hans Christian Cornelius Mortensen in 1899. Other techniques include <hl> radar and satellite tracking <hl>.

Other techniques include <hl> radar and satellite tracking <hl> .


Question: How are orientation behavior studies traditionally carried out?

Orientation behaviour studies have been traditionally carried out using variants of a setup known as the Emlen funnel, which consists of a circular cage with the top covered by glass or wire-screen so that either the sky is visible or the setup is placed in a planetarium or with other controls on environmental cues. The orientation behaviour of the bird inside the cage is studied quantitatively using the distribution of marks that the bird leaves on the walls of the cage. Other approaches used in pigeon homing studies make use of the direction in which the bird vanishes on the horizon.

Answer: the Emlen funnel

<hl> Orientation behaviour studies have been traditionally carried out using variants of a setup known as the Emlen funnel , which consists of a circular cage with the top covered by glass or wire-screen so that either the sky is visible or the setup is placed in a planetarium or with other controls on environmental cues. <hl> The orientation behaviour of the bird inside the cage is studied quantitatively using the distribution of marks that the bird leaves on the walls of the cage. Other approaches used in pigeon homing studies make use of the direction in which the bird vanishes on the horizon.

Orientation behaviour studies have been traditionally carried out using variants of a setup known as <hl> the Emlen funnel <hl>, which consists of a circular cage with the top covered by glass or wire-screen so that either the sky is visible or the setup is placed in a planetarium or with other controls on environmental cues. The orientation behaviour of the bird inside the cage is studied quantitatively using the distribution of marks that the bird leaves on the walls of the cage. Other approaches used in pigeon homing studies make use of the direction in which the bird vanishes on the horizon.

Orientation behaviour studies have been traditionally carried out using variants of a setup known as <hl> the Emlen funnel <hl> , which consists of a circular cage with the top covered by glass or wire-screen so that either the sky is visible or the setup is placed in a planetarium or with other controls on environmental cues.


Question: What shape is the cage in the Emlen funnel?

Answer: circular

<hl> Orientation behaviour studies have been traditionally carried out using variants of a setup known as the Emlen funnel, which consists of a circular cage with the top covered by glass or wire-screen so that either the sky is visible or the setup is placed in a planetarium or with other controls on environmental cues. <hl> The orientation behaviour of the bird inside the cage is studied quantitatively using the distribution of marks that the bird leaves on the walls of the cage. Other approaches used in pigeon homing studies make use of the direction in which the bird vanishes on the horizon.

Orientation behaviour studies have been traditionally carried out using variants of a setup known as the Emlen funnel, which consists of a <hl> circular <hl> cage with the top covered by glass or wire-screen so that either the sky is visible or the setup is placed in a planetarium or with other controls on environmental cues. The orientation behaviour of the bird inside the cage is studied quantitatively using the distribution of marks that the bird leaves on the walls of the cage. Other approaches used in pigeon homing studies make use of the direction in which the bird vanishes on the horizon.