Bird_migration

qas: question: Where does migration mainly occur?
answers: text: the northern hemisphere

question: Why do birds primarily migrate?
answers: text: availability of food

question: Which birds migrate?
answers: text: Many species

question: What is bird migration?
answers: text: the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds

question: What is a cause of death to birds during migration?
answers: text: humans
context: Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting by humans, and is driven primarily by availability of food. It occurs mainly in the northern hemisphere, where birds are funnelled on to specific routes by natural barriers such as the Mediterranean Sea or the Caribbean Sea.

qas: question: When was migration first recorded?
answers: text: 3,000 years ago

question: Who recorded the earliest records of migration?
answers: text: Homer and Aristotle, and in the Book of Job

question: Where was Johannes Leche from?
answers: text: Finland

question: Which species of birds were recorded 3,000 years ago?
answers: text: storks, turtle doves, and swallows

question: What is a major threat to migratory birds?
answers: text: habitat destruction
context: Historically, migration has been recorded as much as 3,000 years ago by Ancient Greek authors including Homer and Aristotle, and in the Book of Job, for species such as storks, turtle doves, and swallows. More recently, Johannes Leche began recording dates of arrivals of spring migrants in Finland in 1749, and scientific studies have used techniques including bird ringing and satellite tracking. Threats to migratory birds have grown with habitat destruction especially of stopover and wintering sites, as well as structures such as power lines and wind farms.

qas: question: Which birds migrate the furthest?
answers: text: The Arctic tern

question: Where does the Arctic tern migrate each year?
answers: text: between Arctic breeding grounds and the Antarctic

question: which bird migrates by circling the earth?
answers: text: albatrosses

question: Where do Manx shearwaters migrate?
answers: text: between their northern breeding grounds and the southern ocean

question: What is an example of a shorter migration?
answers: text: altitudinal migrations on mountains such as the Andes and Himalayas
context: The Arctic tern holds the long-distance migration record for birds, travelling between Arctic breeding grounds and the Antarctic each year. Some species of tubenoses (Procellariiformes) such as albatrosses circle the earth, flying over the southern oceans, while others such as Manx shearwaters migrate 14,000 km (8,700 mi) between their northern breeding grounds and the southern ocean. Shorter migrations are common, including altitudinal migrations on mountains such as the Andes and Himalayas.

qas: question: What causes the timing of migration?
answers: text: changes in day length

question: How do migrating birds navigate?
answers: text: celestial cues from the sun and stars

question: How else to migrating birds navigate?
answers: text: the earth's magnetic field

question: What might help migrating birds navigate?
answers: text: mental maps
context: The timing of migration seems to be controlled primarily by changes in day length. Migrating birds navigate using celestial cues from the sun and stars, the earth's magnetic field, and probably also mental maps.

qas: question: Who recorded early records of migration?
answers: text: Ancient Greek writers

question: Where in the bible does it mention migration?
answers: text: the Book of Job (39:26)

question: What bird is mentioned in the book of Job?
answers: text: hawk
context: Records of bird migration were made as much as 3,000 years ago by the Ancient Greek writers Hesiod, Homer, Herodotus and Aristotle. The Bible also notes migrations, as in the Book of Job (39:26), where the inquiry is made: "Is it by your insight that the hawk hovers, spreads its wings southward?" The author of Jeremiah (8:7) wrote: "Even the stork in the heavens knows its seasons, and the turtle dove, the swift and the crane keep the time of their arrival."

qas: question: Who noted that cranes traveled from Scythia to the Nile?
answers: text: Aristotle

question: Who repeats Aristotle's observations?
answers: text: Pliny the Elder

question: Where did Pliny the Elder repeat Aristotle's observations?
answers: text: in his Historia Naturalis

question: What kind of bird did Aristotle and Pliny the Elder write about?
answers: text: cranes
context: Aristotle noted that cranes traveled from the steppes of Scythia to marshes at the headwaters of the Nile. Pliny the Elder, in his Historia Naturalis, repeats Aristotle's observations.

qas: question: Which bird did Aristotle believe hibernated?
answers: text: swallows

question: Until what year did the belief of hibernating birds persist?
answers: text: 1878

question: Who wrote 182 papers dealing with the hibernation of swallows?
answers: text: Elliott Coues

question: Who wrote "The Natural History of Selborne"?
answers: text: Gilbert White
context: 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".

qas: question: When was migration finally accepted?
answers: text: the end of the eighteenth century

question: Who wrote A History of British Birds?
answers: text: Thomas Bewick

question: What year was Thomas Bewick's book published?
answers: text: 1797

question: Where were Swallows seen flying?
answers: text: between the islands of Minorca and Majorca

question: Which directions were the Swallows flying?
answers: text: northward
context: 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:

qas: question: Who describes an experiment with swallows?
answers: text: Bewick

question: Where did this experiment take place?
answers: text: Britain

question: How did the experiment succeed?
answers: text: they remained warm and dry through the winters

question: How long did the birds stay alive?
answers: text: several years
context: 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:

qas: question: Why do birds migrate?
answers: text: response to changes in food availability, habitat, or weather

question: What are non=migratory birds called?
answers: text: resident or sedentary

question: How many species of birds are there?
answers: text: 10,000

question: How many bird species are long distance migrants?
answers: text: 1800

question: Which direction do birds primarily migrate?
answers: text: north and south
context: 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.

qas: question: Along where do many birds migrate?
answers: text: a flyway

question: What is the most common pattern of migration in the spring?
answers: text: flying north

question: What is the most common directionof migration in autumn?
answers: text: south

question: Why do the birds fly north?
answers: text: to breed
context: 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.

qas: question: What is the primary motivation for migration?
answers: text: food

question: Which birds will not migrate if they are well fed through winter?
answers: text: hummingbirds

question: When do the birds return to warmer regions?
answers: text: autumn

question: what do the longer days of summer provide the birds?
answers: text: time for breeding birds to feed their young.

question: What do diurnal birds produce as opposed to non migratory species?
answers: text: larger clutches
context: 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.

qas: question: What is hightened during migration?
answers: text: Predation

question: Where do Eleonora's falcon breed?
answers: text: Mediterranean islands

question: What do Eleonora's falcon feed their young?
answers: text: southbound passerine migrants

question: What preys on nocturnal passerine migrants?
answers: text: the greater noctule bat

question: What makes birds prone to parasites and pathogens?
answers: text: higher concentrations of migrating birds
context: 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.

qas: question: What is partial migration?
answers: text: not all populations may be migratory

question: Where is partial migration most common?
answers: text: the southern continents

question: In Australia, what percent of non-passerine birds are partially migratory?
answers: text: 44%

question: In Australia, what percent of passerine species are partially migratory?
answers: text: 32%

question: What is leap frog migration?
answers: text: birds that nest at higher latitudes spend the winter at lower latitudes
context: 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.

qas: question: Which sex of the chaffinches Fringilla coelebs migrate earlier?
answers: text: Female

question: Where are chaffinches Fringilla coelebs from?
answers: text: Eastern Fennoscandia

question: When do the chaffinches Fringilla coelebs migrate?
answers: text: autumn
context: 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.

qas: question: How do most migrations begin?
answers: text: the birds starting off in a broad front

question: What to the migrating birds usually follow?
answers: text: mountain ranges or coastlines

question: What obsticals will migrating birds avoid?
answers: text: large stretches of open water

question: What is a common pattern in North America migration?
answers: text: clockwise

question: What are the preferred routes for migration called?
answers: text: flyways
context: 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.

qas: question: How do most birds migrate?
answers: text: in flocks

question: How much energy do geese conserve flying in a flock?
answers: text: 12–20%

question: How much faster do Red knots and dunlins fly in a flock?
answers: text: 3.1 mph

question: How do birds conserve energy?
answers: text: a V-formation

question: What does flying in flocks reduce?
answers: text: energy cost
context: 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.

qas: question: What part of birds was found on an expedition to Mt. Everest?
answers: text: skeletons

question: Which birds have the highest rates of climb to altitude?
answers: text: Bar-headed geese Anser indicus

question: What kind of birds fly low over water?
answers: text: Seabirds

question: What altitude range is most migration recorded?
answers: text: 150 to 600 m

question: Where do most in air collisions occur?
answers: text: below 600 m
context: 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).

qas: question: How do penguins migrate?
answers: text: by swimming

question: How far do penguins travel when they migrate?
answers: text: over 1,000 km

question: How do Dusky grouse migrate?
answers: text: mostly by walking

question: How do Emus migrate long distances during droughts?
answers: text: on foot

question: Where are Emus from?
answers: text: Australia
context: 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.

qas: question: Where do the pink-footed goose migrate?
answers: text: from Iceland to Britain

question: Where do the dark-eyed junco migrate?
answers: text: arctic climates to the contiguous United States

question: Where do the European pied flycatcher breed?
answers: text: Asia and Europe

question: Where does the European pied flycatcher spend the winter?
answers: text: Africa

question: How do young learn migratory routes?
answers: text: during their first migration with their parents
context: 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.

qas: question: What route does a migrating bird usually follow?
answers: text: an hooked or arched line

question: What geographical barriers to land birds try to avoid?
answers: text: large water bodies or high mountain ranges

question: Why do migrating land birds avoid large water bodies or mountain ranges?
answers: text: the lack of stopover or feeding sites

question: Why do broad winged birds avoid geographical barriers?
answers: text: lack of thermal columns
context: 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.

qas: question: What do water birds avoid while migrating?
answers: text: a large area of land without bodies of water

question: Where do brent geese migrate from?
answers: text: the Taymyr Peninsula

question: Where do brent geese migrate to?
answers: text: the Wadden Sea

question: How do brent geese migrate?
answers: text: via the White Sea coast and the Baltic Sea
context: 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.

qas: question: What are waders called in North America?
answers: text: shorebirds

question: Where do dunlin Calidris alpina migrate to?
answers: text: warmer locations in the same hemisphere

question: Where do semiplamated sandpiper C. pusilla migrate to?
answers: text: the tropics in the Southern Hemisphere

question: Where do western sandpiper Calidris migrate from?
answers: text: Arctic breeding grounds
context: A similar situation occurs with waders (called shorebirds in North America). Many species, such as dunlin Calidris alpina and western sandpiper Calidris mauri, undertake long movements from their Arctic breeding grounds to warmer locations in the same hemisphere, but others such as semipalmated sandpiper C. pusilla travel longer distances to the tropics in the Southern Hemisphere.

qas: question: What does successful migration depend on for some waders?
answers: text: the availability of certain key food resources

question: Where do migrants refuel?
answers: text: stopover points along the migration route

question: Where is an important stopover location?
answers: text: the Bay of Fundy

question: What is another stopover location?
answers: text: Delaware Bay
context: For some species of waders, migration success depends on the availability of certain key food resources at stopover points along the migration route. This gives the migrants an opportunity to refuel for the next leg of the voyage. Some examples of important stopover locations are the Bay of Fundy and Delaware Bay.

qas: question: Which bird has the longest migration?
answers: text: bar-tailed godwits

question: How far do bar-tailed godwits travel to migrate?
answers: text: 11,000 km

question: Where do bar-tailed godwits migrate from
answers: text: Alaska

question: Where do bar-tailed godwits migrate to?
answers: text: New Zealand

question: How much of the bar-tailed godwits bodyweight is stored as fat before migration?
answers: text: 55 percent
context: Some bar-tailed godwits Limosa lapponica have the longest known non-stop flight of any migrant, flying 11,000 km from Alaska to their New Zealand non-breeding areas. Prior to migration, 55 percent of their bodyweight is stored as fat to fuel this uninterrupted journey.

qas: question: Which seabird has the longest-distance migration?
answers: text: The Arctic tern

question: Which bird sees more daylight than any other during migration?
answers: text: The Arctic tern

question: How long did one Arctic tern take to migrate?
answers: text: three months

question: How far did the Arctic tern chick travel?
answers: text: 22,000 km

question: Where do tubenosed birds breed?
answers: text: the southern hemisphere
context: Seabird migration is similar in pattern to those of the waders and waterfowl. Some, such as the black guillemot Cepphus grylle and some gulls, are quite sedentary; others, such as most terns and auks breeding in the temperate northern hemisphere, move varying distances south in the northern winter. The Arctic tern Sterna paradisaea has the longest-distance migration of any bird, and sees more daylight than any other, moving from its Arctic breeding grounds to the Antarctic non-breeding areas. One Arctic tern, ringed (banded) as a chick on the Farne Islands off the British east coast, reached Melbourne, Australia in just three months from fledging, a sea journey of over 22,000 km (14,000 mi). Many tubenosed birds breed in the southern hemisphere and migrate north in the southern winter.

qas: question: Which species are great wanderers?
answers: text: pelagic

question: Which bird broke a record in how far it flew over it's life?
answers: text: Manx shearwater

question: How far did a Manx shearwater fly over it's lifespan?
answers: text: 8 million km

question: How long did the Manx shearwater live?
answers: text: 50 year

question: How far will Puffinus griseus migrate each year?
answers: text: 14,000 km
context: The most pelagic species, mainly in the 'tubenose' order Procellariiformes, are great wanderers, and the albatrosses of the southern oceans may circle the globe as they ride the "roaring forties" outside the breeding season. The tubenoses spread widely over large areas of open ocean, but congregate when food becomes available. Many are also among the longest-distance migrants; sooty shearwaters Puffinus griseus nesting on the Falkland Islands migrate 14,000 km (8,700 mi) between the breeding colony and the North Atlantic Ocean off Norway. Some Manx shearwaters Puffinus puffinus do this same journey in reverse. As they are long-lived birds, they may cover enormous distances during their lives; one record-breaking Manx shearwater is calculated to have flown 8 million km (5 million miles) during its over-50 year lifespan.

qas: question: What do some large broad-winged birds rely on to help them soar?
answers: text: thermal columns of rising hot air

question: When do large birds of pray migrate?
answers: text: daytime

question: What is one of the heaviest migratory funnels?
answers: text: Batumi bottleneck

question: How much of their body weight do honey buzzards lose during migration?
answers: text: 10 to 20%

question: How many birds funnel through Batumi, Georgia each year?
answers: text: hundreds of thousands
context: Some large broad-winged birds rely on thermal columns of rising hot air to enable them to soar. These include many birds of prey such as vultures, eagles, and buzzards, but also storks. These birds migrate in the daytime. Migratory species in these groups have great difficulty crossing large bodies of water, since thermals only form over land, and these birds cannot maintain active flight for long distances. Mediterranean and other seas present a major obstacle to soaring birds, which must cross at the narrowest points. Massive numbers of large raptors and storks pass through areas such as the Strait of Messina, Gibraltar, Falsterbo, and the Bosphorus at migration times. More common species, such as the European honey buzzard Pernis apivorus, can be counted in hundreds of thousands in autumn. Other barriers, such as mountain ranges, can also cause funnelling, particularly of large diurnal migrants. This is a notable factor in the Central American migratory bottleneck. Batumi bottleneck in the Caucasus is one of the heaviest migratory funnels on earth. Avoiding flying over the Black Sea surface and across high mountains, hundreds of thousands of soaring birds funnel through an area around the city of Batumi, Georgia. Birds of prey such as honey buzzards which migrate using thermals lose only 10 to 20% of their weight during migration, which may explain why they forage less during migration than do smaller birds of prey with more active flight such as falcons, hawks and harriers.

qas: question: When do many insectivorous birds migrate?
answers: text: usually at night

question: Which kinds of birds land for a few days before resuming migration?
answers: text: smaller insectivorous birds

question: What are smaller insectivorous birds referred to?
answers: text: passage migrants

question: How long do passage migrants stop and feed before resuming migration?
answers: text: a few days
context: Many of the smaller insectivorous birds including the warblers, hummingbirds and flycatchers migrate large distances, usually at night. They land in the morning and may feed for a few days before resuming their migration. The birds are referred to as passage migrants in the regions where they occur for short durations between the origin and destination.

qas: question: What is a benefit of nocturnal migration?
answers: text: minimize predation

question: What is a cost of nocturnal migration?
answers: text: loss of sleep

question: How do nocturnal migrants compensate for loss of sleep?
answers: text: Migrants may be able to alter their quality of sleep

question: What is another benefit of nocturnal migration?
answers: text: avoid overheating
context: Nocturnal migrants minimize predation, avoid overheating, and can feed during the day. One cost of nocturnal migration is the loss of sleep. Migrants may be able to alter their quality of sleep to compensate for the loss.

qas: question: What are many long distance migrants genetically programmed to do?
answers: text: respond to changing day length

question: How do species that move short distances know when to migrate?
answers: text: response to local weather conditions

question: Why do mountain and moorland breeders move only altitudinally?
answers: text: to escape the cold higher ground

question: Where do the merlin Falco columbarius migrate to?
answers: text: the coast or towards the south

question: How far do British chaffinch more in their lives?
answers: text: 5 km
context: Many long-distance migrants appear to be genetically programmed to respond to changing day length. Species that move short distances, however, may not need such a timing mechanism, instead moving in response to local weather conditions. Thus mountain and moorland breeders, such as wallcreeper Tichodroma muraria and white-throated dipper Cinclus cinclus, may move only altitudinally to escape the cold higher ground. Other species such as merlin Falco columbarius and Eurasian skylark Alauda arvensis move further, to the coast or towards the south. Species like the chaffinch are much less migratory in Britain than those of continental Europe, mostly not moving more than 5 km in their lives.

qas: question: How many evolutionary origins do short distance passerine migrants have?
answers: text: two

question: Which species have long-distance migrants in the same family?
answers: text: the common chiffchaff Phylloscopus collybita

question: Why have some specied progressively shortened their return migration?
answers: text: to stay in the northern hemisphere
context: Short-distance passerine migrants have two evolutionary origins. Those that have long-distance migrants in the same family, such as the common chiffchaff Phylloscopus collybita, are species of southern hemisphere origins that have progressively shortened their return migration to stay in the northern hemisphere.

qas: question: What species has no long-distance migratory relatives?
answers: text: the waxwings Bombycilla

question: What are the waxwings Bombycilla moving in response to?
answers: text: winter weather and the loss of their usual winter food

question: Why are the waxwing Bombycilla not migrating for?
answers: text: enhanced breeding opportunities
context: Species that have no long-distance migratory relatives, such as the waxwings Bombycilla, are effectively moving in response to winter weather and the loss of their usual winter food, rather than enhanced breeding opportunities.

qas: question: Where is there little variation in the length of day throughout the year?
answers: text: In the tropics

question: Why does altitudinal migration occur in some tropical birds?
answers: text: to obtain more of their preferred foods

question: What are tropical birds preferred foods?
answers: text: fruits

question: Where is it always warm enough for food supply?
answers: text: In the tropics
context: In the tropics there is little variation in the length of day throughout the year, and it is always warm enough for a food supply, but altitudinal migration occurs in some tropical birds. There is evidence that this enables the migrants to obtain more of their preferred foods such as fruits.

qas: question: For what reason would birds mor far beyond the normal range?
answers: text: a good breeding season followed by a food source failure

question: How many times did Bohemian waxwings come to Britain in the nineteeth century?
answers: text: five

question: How many times did Bohemian waxwings come to Britain between 1937 and 200?
answers: text: 18

question: What years did Red crossbills invade England?
answers: text: 1251, 1593, 1757, and 1791
context: Sometimes circumstances such as a good breeding season followed by a food source failure the following year lead to irruptions in which large numbers of a species move far beyond the normal range. Bohemian waxwings Bombycilla garrulus well show this unpredictable variation in annual numbers, with five major arrivals in Britain during the nineteenth century, but 18 between the years 1937 and 2000. Red crossbills Loxia curvirostra too are irruptive, with widespread invasions across England noted in 1251, 1593, 1757, and 1791.

qas: question: In which hemisphere does bird migration primarily happen?
answers: text: Northern

question: Where do birds from high northern latitutes migrate to?
answers: text: south

question: Why do birds migrate south in winter?
answers: text: food becomes scarce

question: Which species of seabirds are more likely to migrate?
answers: text: species of the Southern Hemisphere

question: Why are seabirds from the southern hemisphere more likely to migrate?
answers: text: there is a large area of ocean in the Southern Hemisphere
context: Bird migration is primarily, but not entirely, a Northern Hemisphere phenomenon. This is because land birds in high northern latitudes, where food becomes scarce in winter, leave for areas further south (including the Southern Hemisphere) to overwinter, and because the continental landmass is much larger in the Northern Hemisphere. In contrast, among (pelagic) seabirds, species of the Southern Hemisphere are more likely to migrate. This is because there is a large area of ocean in the Southern Hemisphere, and more islands suitable for seabirds to nest.

qas: question: What controls a birds migration?
answers: text: a primitive trait

question: How do birds navigate and orient themselves during migration?
answers: text: endogenous programs as well as learning

question: What is a primitive trait present even in non migrating birds?
answers: text: migration

question: What is a complex phenomenon in regards to migration?
answers: text: The ability to navigate
context: The control of migration, its timing and response are genetically controlled and appear to be a primitive trait that is present even in non-migratory species of birds. The ability to navigate and orient themselves during migration is a much more complex phenomenon that may include both endogenous programs as well as learning.

qas: question: What is the primary cue for migration?
answers: text: changes in the day length

question: How do birds act in the period before migration?
answers: text: higher activity

question: What does Zugunruhe mean in English?
answers: text: migratory restlessness

question: What do caged birds display that corresponds with migratory direction in nature?
answers: text: preferential flight direction

question: When do caged birds change their preferential direction?
answers: text: the same time their wild conspecifics change course
context: 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 the same time their wild conspecifics change course.

qas: question: What is it called when males return earlier to the breeding sites than females?
answers: text: protandry

question: What happens in polygynous species with sexual dimophism?
answers: text: males tend to return earlier to the breeding sites

question: Why do males in polygynous species return before the females?
answers: text: sexual dimorphism
context: In polygynous species with considerable sexual dimorphism, males tend to return earlier to the breeding sites than their females. This is termed protandry.

qas: question: What is navigation based on?
answers: text: a variety of senses

question: What do many birds use as a compass?
answers: text: sun

question: What does using the sun for direction involve?
answers: text: the need for making compensation based on the time

question: What else is navigation based on?
answers: text: use visual landmarks

question: What is magnetoception?
answers: text: the ability to detect magnetic fields
context: 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.

qas: question: When do long distance migrants disperse?
answers: text: as young birds

question: What do young birds form attachments to?
answers: text: potential breeding sites

question: What else do young birds form attachments to?
answers: text: wintering sites

question: What happens when the site attachment is made?
answers: text: they show high site-fidelity

question: Where do migrating birds visit?
answers: text: the same wintering sites year after year
context: 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.

qas: question: What are older migrating birds better at?
answers: text: making corrections for wind drift

question: How was the migrating of ospretys and honey buzzards tracked?
answers: text: Satellite

question: What do the birds do to successfully perform long distance migration?
answers: text: recognize habitats and form mental maps

question: What are examples of day migrating raptors?
answers: text: ospreys and honey buzzards
context: 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.

qas: question: What two electromagnetic tools do birds use to find their destinations?
answers: text: one that is entirely innate and another that relies on experience

question: Where is the neural connection that is active during migration located?
answers: text: between the eye and "Cluster N"

question: What is Cluster N?
answers: text: the part of the forebrain that is active during migrational orientation

question: What is a young bird on it's first migration compared to?
answers: text: a boy scout with a compass but no map

question: How does the magnetic field help the bird at different latitudes?
answers: text: let it know when it has reached its destination
context: 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.

qas: question: How can migrating birds lose their way?
answers: text: flying past their destinations

question: What is flying past their destinations called?
answers: text: spring overshoot

question: What location has become famous for bird overshooters?
answers: text: Point Pelee National Park

question: What other location is famous for spring overshoot?
answers: text: Spurn in England

question: Where do bird overshooters end up?
answers: text: further north than intended
context: 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.

qas: question: What is it called when the genetic programing of young birds fail?
answers: text: Reverse migration

question: What is reverse migration?
answers: text: where the genetic programming of young birds fails to work properly

question: What does reverse migration lead to?
answers: text: rarities turning up as vagrants thousands of kilometres out of range

question: How far out of range can rarities get?
answers: text: thousands of kilometres
context: 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.

qas: question: What is it called when birds from one region join birds from a different region?
answers: text: abmigration

question: What kind of bird is most likely to abmigrate?
answers: text: waterfowl

question: Who do abmigrating birds return with?
answers: text: the new population
context: 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.

qas: question: What is a re-introduction scheme?
answers: text: to teach a migration route to a flock of birds

question: What did they use to teach birds a migration route?
answers: text: microlight aircraft

question: Which birds did they reintroduce to the US?
answers: text: whooping cranes

question: Which birds did they use as a trial run?
answers: text: Canada geese
context: 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.

qas: question: What do birds need to change to meet the demands of migration?
answers: text: their metabolism

question: How often do birds molt?
answers: text: usually once a year

question: How do birds store energy?
answers: text: through the accumulation of fat and the control of sleep

question: Why do birds need to molt?
answers: text: feathers of a bird suffer from wear-and-tear

question: When do birds molt?
answers: text: varies with some species
context: 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.

qas: question: How was migration developed?
answers: text: independently

question: What is highly labile?
answers: text: Migration in birds

question: What causes the behavioral adaptations necessary for migration?
answers: text: genetic control

question: What exists in nearly all avian lineages?
answers: text: genetic framework for migratory behavior
context: 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.

qas: question: What percentage increase in flight distance will often be adaptive?
answers: text: 20%

question: What kind of bird flies less efficiently?
answers: text: a bird that loads itself with food

question: What type of bird show circuitous migratory routes?
answers: text: Swainson's thrush

question: Where do Swainson's thrush fly from?
answers: text: far east across North America
context: 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.

qas: question: What is expected to have an effect on migration timing?
answers: text: climatic changes

question: What have studies shown regarding climate change?
answers: text: timing changes in migration

question: What else is climate change been shown to change?
answers: text: breeding as well as population variations
context: 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.

qas: question: What other species does migration help?
answers: text: ectoparasites such as ticks and lice

question: What is a greater threat of disease transmission?
answers: text: import of pet and domestic birds

question: What has been studied as a mechanism of disease transmission?
answers: text: bird migration

question: What has a role in the dispersal of propagules of plants and plankton?
answers: text: Birds

question: What virus is maintained in birds without lethal effects?
answers: text: West Nile Virus
context: 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.

qas: question: Who takes advantage of migrating birds?
answers: text: Greater noctule bats

question: What do greater noctule bats feed on?
answers: text: nocturnal migrating passerines

question: What do some birds of prey specialize on?
answers: text: migrating waders
context: 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.

qas: question: What is the oldest way to study migration?
answers: text: marking

question: How have swans been marked?
answers: text: a nick on the beak

question: Since when have swans been marked?
answers: text: 1560

question: Who was scientific ringing pioneered by?
answers: text: Hans Christian Cornelius Mortensen

question: What are other forms of studying migration?
answers: text: radar and satellite tracking
context: 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.

qas: question: How are orientation behavior studies traditionally carried out?
answers: text: the Emlen funnel

question: What shape is the cage in the Emlen funnel?
answers: text: circular

question: What is studied quantitatively inside the cage?
answers: text: The orientation behaviour

question: What does the bird leave on the walls of the cage?
answers: text: marks

question: Where does the homing pigeon vanish?
answers: text: on the horizon
context: 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.

qas: question: What threatens some bird species?
answers: text: Hunting along migration routes

question: What species declined due to hunting in Afghanistand and Asia?
answers: text: Siberian cranes

question: When were birds last seen in Keoladeo National Park?
answers: text: 2002

question: What can power lines, wind farms and oil rigs affect?
answers: text: migratory birds

question: What are other migration hazards?
answers: text: pollution, storms, wildfires, and habitat destruction
context: Hunting along migration routes threatens some bird species. The populations of Siberian cranes (Leucogeranus leucogeranus) that wintered in India declined due to hunting along the route, particularly in Afghanistan and Central Asia. Birds were last seen in their favourite wintering grounds in Keoladeo National Park in 2002. Structures such as power lines, wind farms and offshore oil-rigs have also been known to affect migratory birds. Other migration hazards include pollution, storms, wildfires, and habitat destruction along migration routes, denying migrants food at stopover points. For example, in the East Asian–Australasian Flyway, up to 65% of key intertidal habitat at the Yellow Sea migration bottleneck has been destroyed since the 1950s.