Why birds return to their native lands. Do migratory birds return to their place of birth? Why do migratory birds come back?

20.02.2024

Migration is characteristic of many living beings. Many animals and fish migrate seasonally on long journeys. Some bird species migrate south due to the change of season. But why do they do this? With the same salmon, everything is relatively clear - the red fish leaves the rivers for the sea to feed, but returns to breed. There is not enough food in the river for large fish, and in the sea there are no conditions for spawning. But why do birds fly away? Why do some of them live sedentary in their own territory, while others travel vast distances?

This is mainly due to the food supply and climate. This issue is worthy of in-depth consideration, because the mechanisms of flights are not clear-cut.

Is it only the cold that stimulates flights?

Many ordinary people are sure that birds fly away because of the cold. Indeed, in the fall, temperatures drop rapidly, and people have to take warm clothes out of their closets. But do birds really freeze? This point is very doubtful, since the plumage of the vast majority of them is very warm. Even a domestic parrot is quite capable of enduring the winter cold. And large individuals, the same cranes that leave the northern latitudes in beautiful wedges, should not freeze at all. Under the feathers of each bird there is a layer of down, which provides reliable thermal insulation even at temperatures of -45 degrees. What drives them to fly?

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Interesting facts about birds

The situation becomes clearer if you take a closer look at the diet of migratory birds and their non-migratory counterparts. Wintering is easily tolerated by omnivorous birds, which easily find food for themselves in any season, especially near humans. Sparrows, crows, pigeons - they can all find enough food for themselves. If we consider storks and cranes, with the arrival of cold weather they lose access to food. The ponds freeze, they cannot hunt frogs and lizards. Insectivorous birds are also left without food - in winter, insects disappear, some of them die, others hibernate.

Why do birds come back?

In the southern regions, birds find adequate nutrition and can survive the winter. But what drives them back, because they could stay there forever? It turns out that this moment is associated with reproduction, as in fish. As the breeding season approaches, the birds' bodies begin to produce the corresponding hormones and other active substances, and with an increase in their volume in the blood, the birds return to the place where they themselves were once born. They fly to the north to give birth to a new generation, which by autumn will fly south with their parents, and then return home to the north.

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Mandarin duck - interesting facts

Where is the homeland of migratory birds?

Such an incredible craving for the Motherland is instinctively inherent in birds; they reproduce only where they themselves once hatched from an egg. They fly to the south temporarily, and the northern regions can be considered their homeland. Birds strongly and firmly remember everything that was seen and felt by them immediately after hatching. It is worth remembering that even ducklings consider their mother the one they saw first after birth, and can persistently follow not only their true mother duck, but also a dog or a human.

Sokolov Leonid Viktorovich

Why migratory birds return home

Our knowledge of the phenomenon of home fidelity in birds is obtained through the use of a simple but very effective method of individual marking. Without bird ringing and subsequent detection, our ideas about home fidelity, settlement, migrations of birds, etc. would be largely speculative. Banding has provided us with objective facts that constitute a golden fund of scientific data.

"The science"

Introduction

Most vertebrates, despite their excellent ability to move, prefer to live in permanent habitats. Occupying specific territories with which they establish strong ties at certain periods of their lives, they strive to retain them for as long as possible. Even among such mobile organisms as migratory fish, sea turtles, migratory birds, and some mammals (bats, pinnipeds, and cetaceans) that undertake long-distance seasonal migrations, there is a surprising constancy of habitats. Unlike sedentary animals, such animals not only need to have strong territorial ties with different habitats (breeding, wintering, molting, etc.), often thousands of kilometers apart, but also have perfect migration and navigation mechanisms that ensure their return to these areas. Migrating animals, covering vast distances, for the most part did not wander, constantly changing their habitats, but developed and improved the ability to return home (homing), an ability that all territorial animals possess to one degree or another.

The fidelity of animals to a permanent territory leads to the formation in the process of evolution of populations that are finely adapted to external environmental conditions. The nature of these populations, their size, isolation and constancy cannot be clarified without an objective assessment of the level of fidelity of animals to a certain territory, without a detailed analysis of the territorial connections themselves and the mechanism of their formation. The outstanding American evolutionist E. Mayr wrote in one of his books that territoriality and a sense of home in birds are important internal factors that reduce the exchange of genes between populations. A sense of home, combined with territoriality, sharply limits the dispersal of individuals and facilitates the process of speciation. If animals did not have the desire to live in a permanent territory, the picture of their existence on our planet would be different.

The study of territorial connections in migratory birds is also very important for the development of a general theory of bird migration. The territorial connections formed by migratory birds in different parts of the planet largely determine the length and direction of their annual migrations. Territorial connections can play an important role in regulating readiness for migration - migratory state and behavior in birds. At the same time, studying the mechanism by which birds form a connection with the territory contributes to our understanding of the complex mechanisms of orientation and navigation of animals in space, which many scientists - ornithologists, physiologists, biophysicists, physicists, mathematicians and engineers - are currently struggling to decipher.

The study of territorial connections in birds is not only of theoretical interest. There are two most significant ways of practical application of this knowledge. Firstly, relocation, acclimatization and re-acclimatization of animals. Without knowledge of the time and mechanism of formation of territorial connections in animals, in particular birds, their relocation and subsequent acclimatization cannot be successful. The practice of populating forest plantations with beneficial birds, which was intensively carried out in our country in the 50s, showed that without theoretical development of the problem of territorial connections, these measures are ineffective. Secondly, it is necessary to actively help in the reproduction of those species that are on the verge of extinction. Currently, many countries around the world have already created special services for the protection and reproduction of wildlife.

In this book, the author, who has been studying territorial connections among migratory birds for about 20 years, tried to present a modern view of one of the most interesting problems of ornithology - the problem of birds' fidelity to home and homeland. The book analyzes not only the original data obtained by the author and employees of the Biological Station of the Zoological Institute of the USSR Academy of Sciences, located on the Curonian Spit of the Baltic Sea, but also data from world literature (until 1990). The author is deeply grateful to everyone who participated in obtaining what is analyzed in this book material, and also helped him in preparing it for publication.

Loyalty of birds to their homeland (philopatry)

A sense of loyalty to home is a special property that is possessed by a wide variety of organisms, from insects (bees, wasps, ants, etc.) to primates. This feeling has an instinctive basis and manifests itself in the individual in the desire to return “home” - to a place familiar to it after a temporary absence. For birds, “home” can be a place of birth, breeding (nesting territory), wintering (wintering territory), molting, stopovers during migration, and other territories. In a word, any place that an individual constantly visits during its life can be conditionally called its home.

The return of birds home is usually called a special term - “homing” (from the English home - house). When referring to the return of birds to the nest, they usually speak of nest homing; when birds return to their wintering place, they speak of wintering homing. Sometimes the concepts of “near” and “far” homing are used when they want to note from what distances a bird returns.

American ornithologists, in particular L. Mewald, proposed calling the return of birds to their place of birth philopatry, which means, translated from Greek, “love of the fatherland, homeland.” The term "philopatry" is now applied to a wide range of similar, and perhaps identical, phenomena of fidelity to one's homeland found in a wide variety of animal groups. Often, philopatry refers to the fidelity of birds not only to the place or area of birth, but also to the place of their former nesting and wintering, which deprives the term of its unambiguity.

In Russian literature, the return of birds to the area of birth or previous nesting is often called “nesting conservatism.” From my point of view, this term is unfortunate, since it literally means loyalty to the nest, and not to the nesting territory. Most birds, with the exception of some species - storks, herons, raptors and other large birds, build a new nest every year. If we still talk about conservatism, then it is more correct to call it territorial, but it is better to use the terms used in world literature.

How "home fidelity" is studied in birds

The assumption that migratory birds return “home” in the spring arose among people a long time ago, probably in the process of observing the arrival of birds (storks, swallows, swifts, etc.) that nest near people. The most curious ones tied colored threads, laces or ribbons to the birds’ legs, thus carrying out individual marking. Having discovered a bird with its mark in the spring, a person for the first time received reliable evidence of the birds' fidelity to their home. However, tagging became a scientific method only after the Danish teacher H. Mortensen invented a zinc ring for individual marking of birds in 1898. A modern ring is a kind of bird passport, on which the series, number, sometimes country, ringing point and other information are stamped. Currently, for individual tagging of birds, ornithologists also use multi-colored plastic ring-collars for tagging large birds, such as swans, geese, cranes and herons, the numbers on which can be seen with binoculars or a telescope. Wing plate tags are also used to mark ducks, and “tie” tags are used to mark waders. To mark small passerine birds, various types of colored rings are used - plastic, celluloid, wire, etc. Thanks to the colored rings, which are put on the bird’s paw in a certain combination, you can observe it without catching it for a long time. Generally speaking, without individual identification it is impossible to successfully conduct studies on the territorial distribution and behavior of birds.

Since the invention of individual rings, thanks to the efforts of many ornithologists, both professional and amateur, a huge amount of material on ring returns has been accumulated in different countries of the world, which has confirmed that many migratory birds do indeed return to nest and winter in their former areas. As an indicator of the fidelity of birds to any territory, the so-called percentage of return is used, i.e. the proportion of birds that returned to this territory from among all those previously ringed in it. It is interesting that ichthyologists involved in the breeding of chain anadromous fish species (Pacific salmon, salmon, sturgeon), this indicator (the percentage of fish returning to the place where juveniles are released) is widely used to assess the effectiveness of these works. Unfortunately, it is quite difficult to determine the real value of the return of ringed birds, since control over returning individuals is rarely complete. Only in some species (for example, great tit, pied flycatcher, common starling, nesting in artificial nests and birdhouses), it is possible to carry out sufficiently effective control of breeding individuals, and then only when the number of natural hollows in the study area is small. For example, on the Curonian Spit of the Baltic Sea in the area where the field station of the Biological Station of the Zoological Institute of the USSR Academy of Sciences is located (Fig. 1), almost all (95%) nesting pied flycatchers are caught by us. The forest here is represented mainly by 20–30-year-old plantings of Scots pine and small birch forests, where there are very few natural hollows. At the same time, in other parts of the spit, where deciduous tree species predominate - black alder, birch - with a sufficient number of hollows, the effectiveness of pied flycatcher control is lower. If in the hospital area the return of pied flycatchers to the area of birth is about 9%, then in other parts it is half as low.

Why do migratory birds return in the spring? May 10th, 2018

Below we will briefly consider these three aspects.

How?

If migratory birds are kept in captivity, they experience disturbance during normal seasonal migrations. This state was called migratory. At this time, for example, you can observe atypical activity at night. This is due to the fact that small birds fly mainly at night. That is, they seem to be trying to realize their desire to migrate even if they (in captivity) are not allowed to do this.

Moreover, birds try to orient themselves in the direction where they should normally fly. This feature is widely used in studying bird orientation using so-called round cells, or Kramer cells, named after the German ornithologist Gustav Kramer. In such cages (round in shape) there are perches around the perimeter, and one perch is located in the center of the cage. When jumping, it is more convenient for the bird to jump from the central perch to one of the peripheral ones. Based on where the most frequently visited peripheral perch is oriented (to the cardinal points), it is determined in which direction the bird “wants” to migrate.

So, the desire to migrate south (in autumn) or return home (in spring) manifests itself in birds even when they are not allowed to do so. That is, the migratory state is, in fact, an instinctive phenomenon. It is triggered in our birds mainly by the relationship between dark and light time of day (the so-called photoperiod). A certain value of this parameter is a kind of migration trigger.
This has been shown, among other things, experimentally.

How birds find their way

When choosing a direction, birds can use several sources of information.

The solar disk by which they determine direction is important for migrating birds. The sun constantly changes its position in the sky during the day, so it can be used for orientation only by taking into account temporary compensation. In other words, birds must have their own “internal clock.” And, indeed, birds have this ability. Interestingly, birds can navigate by sunlight, even without seeing the sun itself (for example, in cloudy weather). To do this, they use polarized light, which occurs when light is scattered and reflected and is always present in the atmosphere.

Another important source of information is the starry sky. In this case, birds are guided by certain stars and their constellations.

Orientation to the sun and stars is not innate. Although the chick, of course, has the prerequisites for the formation of such skills from birth. But in order for the skill to fully develop, the bird must learn. How exactly she does this is still little clear. But the participation of other birds is not required here. This means that birds must have another navigation system, completely innate. Based on it, they could calibrate (“tune”) other orientation systems. This innate system, which is also the most ancient, is magnetoreception. Using the Earth's magnetic field, birds can choose the directions “poleward” and “equatorward” (meaning the magnetic pole and the equator). At the same time, the orientation by the magnetic field is rougher than by the sun and stars. For example, in this way it is impossible to distinguish the direction “south” from the direction “north”. Apparently, this is why birds have also learned to use celestial landmarks (sun, stars), which allows them to navigate more accurately.

Finally, something should be said about “ordinary” landmarks. Of course, birds also use them, but the role of this is not entirely clear. There is no doubt that birds can use landmarks when they find themselves in familiar terrain. In addition, landmarks can play a role in choosing a specific migration route. For example, it has long been known that many water birds (ducks, geese) stick to sea coasts or the beds of large rivers when migrating.

For what?

Now let's see why birds need to return home. What is the meaning (function) of this? How does this help them survive? After all, in order for the instinct discussed in the previous subsection to be formed, it must have some kind of value - otherwise it simply would not have arisen.

Several periods can be distinguished in the life of birds. They repeat every year, so we usually talk about an annual cycle. In a typical case, the annual cycle looks like this: nesting, molting, autumn migration, wintering, spring migration, nesting again, and then “down the list.” All of these periods are important, but the nesting period is of particular importance. At this time, birds breed offspring; they require a lot of additional expenditure - both time and energy. Therefore, only those individuals reproduce successfully that do so in places favorable to them, to which they are best adapted.

Why don’t our birds usually nest, for example, in the tropics? There are two main reasons here. Firstly, they are not well adapted to the conditions there. That is, they can live there, get their own food, even sing, but they don’t have enough for more. It is difficult to find a suitable place for a nest, it is difficult to feed the chicks, etc. And secondly, in the tropics there are a lot of local sedentary species that “outplay” migrants in competition - both directly (for example, for nesting shelters) and indirect (for food).

But it also happens that our northern birds find suitable conditions somewhere far in the south and remain to nest there. In some cases, this may even lead to the emergence of new forms over time. A good example is the mallard duck (Anas platyrchynchus, Fig. 1), common in central Russia, including within Moscow. And besides this, it nests throughout North America and Eurasia, from the tundra to the subtropics. So this species is very flexible. Therefore, perhaps it is not surprising that some populations, having found their way to tropical islands during migrations, remained there and became sedentary.

Common mallard (female on the left, male on the right).

Now such forms are even considered separate (but related) species. These are the Hawaiian mallard Anas (platyrhynchus) wyvilliana and the Laysan teal Anas (platyrhynchus) laysanensis, both species from the Hawaiian Islands (Fig. 2).

Rice. 2. Hawaiian mallard (left) and Laysan teal. The males and females of these species do not differ and resemble the female mallard.

There are even more interesting exceptions. One of them is the black silky waxwing (Phainopepla nitens, Fig. 3), which lives in North America. This bird manages to nest twice a year. In the spring she breeds chicks in California. And by autumn it migrates to Colorado. Here she nests again. Such nesting in two different places is a unique case among birds. So, as is generally characteristic of zoology, there are only general tendencies or rules with many different exceptions.

Fig 3. Black silky waxwing (Phainopepla nitens). On the left is a male, on the right is a female.

Finally, we need to briefly tell you why birds generally fly to warmer climes in winter. The main reason is lack of food. Therefore, first of all, those bird species that feed on openly living insects fly away. In winter, such food, of course, cannot be found. So they migrate, one might say, forcedly. The same species that can find food in winter remain in our area. These are, for example, tits, which deftly look for sleeping insects in various crevices and diversify their diet with seeds. Or the Great Spotted Woodpecker (Dendrocopos major), which feeds on spruce and pine seeds in winter.

Why?
But why do birds that nest in northern latitudes and winter in tropical latitudes do this and not otherwise? Why don't they, for example, nest in the tropics in the winter and go to the north to rest in the summer? To answer this, it is also necessary to consider the evolutionary aspect. Namely, the history of species distribution.

The fact is that many of our bird species are of southern origin. All of them are from Africa or South Asia. Over the course of their evolutionary history, they gradually dispersed from these areas. New populations and species were formed, adapting to new, more northern conditions. Faced with unfavorable winter conditions in new conditions, these birds were forced to migrate south. And this path ran to the areas where these species originally originated. A kind of historical memory. Therefore, there is a well-known analogy that the migration path in general terms repeats the distribution path of the species. Of course, it is not necessary to accurately connect the wintering area and the area from which resettlement began. There is a correspondence here, but it is approximate. So, if a species winters in tropical Asia, we can talk about its Asian origin, but not necessarily tropical.

Wintering areas can remain conservative, even if this is not very convenient. This is, for example, the situation with the Dubrovnik bunting (Emberiza aureola), an Asian species that recently spread to Europe, right up to the Baltic states. Of course, it would be shorter for European birds to fly to Africa for the winter, nevertheless, they fly “in the old fashioned way” to Southeast Asia - just like birds from Siberia and the Far East (Fig. 4).

Rice. 4. Nesting (red) and wintering (green) habitats of the Dubrovnik Bunting. The diagram was compiled based on materials from the website xeno-canto.org, photo by A. S. Opaev

Dubrovnik has only recently begun to nest in Europe. But most other species, more ancient immigrants from Asia, changed their wintering places over time. European populations began to spend the winter in Africa - which, obviously, is both closer and more convenient.

Thus, the history of a species is also important for understanding how it behaves now. But none of the three aspects (mechanism, function, evolution), taken separately, can answer the question posed. And only together they paint a complete picture of why and why birds return in the spring.

Alexey Opaev

sources

This question can be answered correctly from at least three different positions. These answers will complement each other and are therefore equally important. First, what is the mechanism of this phenomenon? Secondly, why do birds do this - what is the meaning (function) of this behavior? And, finally, how did it happen that birds fly away somewhere and then return (that is, what is the origin and evolution of this phenomenon)?
How?
If migratory birds are kept in captivity, they experience disturbance during normal seasonal migrations. This state was called migratory. At this time, for example, you can observe atypical activity at night. This is due to the fact that small birds fly mainly at night. That is, they seem to be trying to realize their desire to migrate even if they (in captivity) are not allowed to do this.
Moreover, birds try to orient themselves in the direction where they should normally fly. This feature is widely used in studying bird orientation using so-called round cells, or Kramer cells, named after the German ornithologist Gustav Kramer. In such cages (round in shape) there are perches around the perimeter, and one perch is located in the center of the cage. When jumping, it is more convenient for the bird to jump from the central perch to one of the peripheral ones. Based on where the most frequently visited peripheral perch is oriented (to the cardinal points), it is determined in which direction the bird “wants” to migrate.
So, the desire to migrate south (in autumn) or return home (in spring) manifests itself in birds even when they are not allowed to do so. That is, the migratory state is, in fact, an instinctive phenomenon. It is triggered in our birds mainly by the relationship between dark and light time of day (the so-called photoperiod). A certain value of this parameter is a kind of migration trigger.
This has been shown, among other things, experimentally.
How birds find their way
When choosing a direction, birds can use several sources of information.
The solar disk by which they determine direction is important for migrating birds. The sun constantly changes its position in the sky during the day, so it can be used for orientation only by taking into account temporary compensation. In other words, birds must have their own “internal clock.” And, indeed, birds have this ability. Interestingly, birds can navigate by sunlight, even without seeing the sun itself (for example, in cloudy weather). To do this, they use polarized light, which occurs when light is scattered and reflected and is always present in the atmosphere.
Another important source of information is the starry sky. In this case, birds are guided by certain stars and their constellations.
Orientation to the sun and stars is not innate. Although the chick, of course, has the prerequisites for the formation of such skills from birth. But in order for the skill to fully develop, the bird must learn. How exactly she does this is still little clear. But the participation of other birds is not required here. This means that birds must have another navigation system, completely innate. Based on it, they could calibrate (“tune”) other orientation systems. This innate system, which is also the most ancient, is magnetoreception. Using the Earth's magnetic field, birds can choose the directions “poleward” and “equatorward” (meaning the magnetic pole and the equator). At the same time, the orientation by the magnetic field is rougher than by the sun and stars. For example, in this way it is impossible to distinguish the direction “south” from the direction “north”. Apparently, this is why birds have also learned to use celestial landmarks (sun, stars), which allows them to navigate more accurately.
Finally, something should be said about “ordinary” landmarks. Of course, birds also use them, but the role of this is not entirely clear. There is no doubt that birds can use landmarks when they find themselves in familiar terrain. In addition, landmarks can play a role in choosing a specific migration route. For example, it has long been known that many water birds (ducks, geese) stick to sea coasts or the beds of large rivers when migrating.
For what?
Now let's see why birds need to return home. What is the meaning (function) of this? How does this help them survive? After all, in order for the instinct discussed in the previous subsection to be formed, it must have some kind of value - otherwise it simply would not have arisen.
Several periods can be distinguished in the life of birds. They repeat every year, so we usually talk about an annual cycle. In a typical case, the annual cycle looks like this: nesting, molting, autumn migration, wintering, spring migration, nesting again, and then “down the list.” All of these periods are important, but the nesting period is of particular importance. At this time, birds breed offspring; they require a lot of additional expenditure - both time and energy. Therefore, only those individuals reproduce successfully that do so in places favorable to them, to which they are best adapted.
Why don’t our birds usually nest, for example, in the tropics? There are two main reasons here. Firstly, they are not well adapted to the conditions there. That is, they can live there, get their own food, even sing, but they don’t have enough for more. It is difficult to find a suitable place for a nest, it is difficult to feed the chicks, etc. And secondly, in the tropics there are a lot of local sedentary species that “outplay” migrants in competition - both directly (for example, for nesting shelters) and indirect (for food).
But it also happens that our northern birds find suitable conditions somewhere far in the south and remain to nest there. In some cases, this may even lead to the emergence of new forms over time. A good example is the mallard duck (Anas platyrchynchus, Fig. 1), common in central Russia, including within Moscow. And besides this, it nests throughout North America and Eurasia, from the tundra to the subtropics. So this species is very flexible. Therefore, perhaps it is not surprising that some populations, having found their way to tropical islands during migrations, remained there and became sedentary.

Common mallard (female on the left, male on the right).

Nature has designed the way of life of birds in such a way that many of them constantly migrate from one habitat to another, and this happens due to changing weather conditions. Since the temperature regime greatly affects the life activity and reproduction of birds, they usually leave their native lands when winter comes, and return back in the spring, in March-May.

Arrival of birds after wintering always means one thing: the cold has retreated and given way to warmth. And here many people become interested in finding out which birds arrive first in the spring.

Which birds arrive first?

Many people do not even suspect that all migratory birds follow a certain arrival schedule, and each species strictly follows it. It is also interesting that they all return to their previous place of residence and even to their previously built nests. If something happened to the nest during the absence of the feathered owners, then the latter settle down anew, after which they breed offspring in them.

So, In what order do spring birds arrive?

What other birds arrive in spring?

Speaking about spring feathered messengers, we should not forget about such like the nightingale and the swallow.

First, it’s worth talking about nightingales, because these are the ones that are recognizable by how wonderfully they can sing. And despite its very inconspicuous appearance (this bird is gray with a brownish tint), the nightingale has a charming voice that fascinates everyone without exception.

Another bright symbol of spring is swallows. These birds cannot sing like nightingales, but they love to settle closer to people, often setting up their nests in the entryways, under balconies and eaves of houses. They can also often be seen in gorges above rivers.

Arrival calendar of spring birds

For many, many years, people have been watching the arrival of birds from the warm regions of their native places, and ornithologists, thanks to scientific research, We were able to create a bird arrival calendar:

from March 18 to 20, rooks return;
March 25-April 6 - starlings arrive;
April 1-10 - during this period, finches, larks, swans and thrushes arrive;
April 11-20 - ducks and geese, cranes and seagulls return to their native lands;
end of April - redstarts, tree pipits, chiffchaffs;
first half of May - swallows and flycatchers arrive;
in mid-May, swifts and nightingales usually return;
the orioles return at the end of May.

In addition to certain periods of time during which birds return to their native lands, there are also certain routes along which they travel.

Interesting signs associated with the arrival of birds in spring

Arrival of spring birds - this is always a sign that winter has receded and spring and warm weather are ahead. And for a long time their certain behavior has been associated with certain signs, for example:

It is with the melting of snow and the cheerful whistling of birds marks the arrival of spring. Schoolchildren begin making birdhouses during craft lessons, and the first swallow's nests begin to appear under the roofs of houses.