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Blackbird, thrush, finch and starling ...

... who stays there? This is how birds survive the cold winter

Most birds leave us in autumn to winter in the south. But there are birds that stay here. But which birds are they, how do they manage to withstand the harsh winter conditions and why do they actually stay here?

  • Golden Chickens are the smallest native birds. In winter they often cuddle up on spruce branches. - Photo: Oscar Klose

  • Woodpeckers are resident birds. The green woodpecker wanders far and wide in cold winters and likes to come to gardens, where he can find more food in compost heaps and under fruit trees - Photo: Frank Derer

  • The blackbird hibernated in southern Europe and North Africa until 100 years ago. Now she stays with us all year round - because she finds enough to do in parks and gardens - Photo: Frank Derer

  • The common buzzard eats mice that it can also find in winter. From the north it is now joined by its relative, the Greater Buzzard. - Photo: Frank Derer

  • Rooks breed only in small numbers in Germany. The large accumulations in winter come mainly from Eastern Europe - Photo: Ingo Ludwichowski

  • Tufted duck in winter. Like many others, this species benefits from additional feeding and the warmer temperatures in the city - Photo: Frank Derer

  • Goldammers are partial drawers. This means that birds migrate from one population while those of another do not - Photo: Frank Derer

  • The crested tit lives all year round in pine and mixed forests, where it also finds seeds from cones in winter. - Photo: Frank Derer

  • The bearded tit is a reed inhabitant and is not a migratory bird. In severe winters, it sometimes suffers significant population losses - Photo: Frank Derer

  • The jay buries acorns in the ground and between roots to store food for the winter. However, it does not always find them all and thus contributes to the budding of young oaks - Photo: Frank Derer

  • As a companion to humans, the house sparrow finds enough to eat even in winter. The loss of nesting opportunities causes him much more problems. - Photo: Ingo Ludwichowski

  • The bird of the year 2009, the kingfisher, only gets into trouble in winter when streams and rivers freeze over and it can no longer catch fish - Photo: Frank Derer

  • The field thrush breeds with us, but the troops that roam the fields are mostly birds that rest or hibernate here - Photo: I. Ludwichowski

  • The nuthatch can still find a larva or spider between the tree and bark, but also takes beechnuts and nuts, which it pounds open - Photo: Frank Derer

It gets quiet when it gets colder. Where there used to be lively birdsong, it is now quiet. Because swifts, nightingales and chiffchaffes have moved to the warm south as well as our storks. But they do exist, the birds that defy the cold and stay with us. They also do not hibernate like some mammals, but are awake and mobile. But which birds are they? How do they manage to withstand the harsh conditions such as lack of food and freezing temperatures and why do they stay here at all?

Different adaptation strategies

Robin - Photo: Bernd Birkhahn

As animals of the same temperature as humans, birds must try to maintain their body temperature, which is between 38 and 42 degrees Celsius. In addition, they have the ability to fluff their plumage so much that they look like a feather ball. This shape is no coincidence, because the sphere has the smallest surface area in relation to the body volume, which means that the least amount of heat is lost. The plumage looks like a down jacket with a warm air cushion.

A special heat exchange system prevents the birds from losing heat through their mostly bare legs. In this way, the downward running blood gives off its warmth to the blood flowing back into the body in good time and cools the legs to almost zero degrees. This is the only way to ensure that ducks, for example, do not freeze on the ice of a body of water and their feet still do not die off.

Birds can also “soak up the sun”. They do this primarily with their dark plumage, which does not even reflect 20 percent of the sun's rays and thus actually warm the bird. On particularly cold nights, birds can also artificially lower their body temperature. You then fall into a kind of rigidity that significantly reduces your metabolism and thus energy consumption.

Save energy and recharge your batteries

Greenfinch in the snow - Photo: Frank Derer

In order to maintain body heat, however, it is primarily necessary to supply energy through food. Many birds that are actually insectivores, such as titmice or nuthatch, now also selectively include seeds, nuts and grains in their diet, because these are high-fat and therefore high-energy food. Berries and legumes are also ripe on trees and bushes in autumn are now available to the hungry bird world for a long time.

Small spiders and insects, as well as their eggs and larvae, can also be captured under tree bark, between roots or in compost heaps. As the days are shorter and the nights longer in winter, the birds have less time to search for food. For this reason, many types of reservoirs build: jays bury acorns in the ground, marsh, fir and crested tits hide seeds and kernels in crevices of bark.

Stay here or move away - there's something in between

Ducks also move to more distant ice-free waters when the cold snaps - Photo: Frank Derer

However, not all of the birds we observe now are in their breeding home all year round. The house sparrow or the woodpecker belong to these so-called "resident birds", but ducks, tits and finches, for example, are considered to be "barnacles" that only avoid unfavorable weather zones in small areas. Blackbirds and robins, for example, are considered “partial migrants”. Some individuals or populations migrate because of their hereditary predisposition, others stay.

Different populations can hibernate together in the winter quarters, or the northern conspecifics fly over those at home from southern populations. However, birds also come from the north and east and overwinter with us. They include waxwing, rook and mountain finch.

While severe winters represent a period of rest for nature on the one hand, they also act as a selection mechanism. Weak animals in a population that cannot survive winter give way to birds from elsewhere, which are more resilient and can reproduce successfully. Sometimes there is such a sharp drop in populations in severe winters, such as the kingfisher or the bearded tit, that the populations need years to recover.

Migratory birds become resident birds

Yet despite these ruthless effects, it cannot be said that migratory birds are better off. On the one hand, the flight, often over thousands of kilometers, costs a lot of time and a lot of energy and, on the other hand, it harbors many dangers: Habitat changes in winter areas, bad weather on the train and illegal bird trapping in southern Europe and North Africa sometimes make these species difficult to create .

Star photo: NABU / Günter Stoller

The increasing global warming and the settlement of cities have led to more and more migratory birds moving shorter distances or even becoming resident birds. Many cranes overwinter in France instead of southern Spain. The flight route has been shortened by a third compared to before. Other species sometimes stop moving at all or avoid the cold for a short time. This tendency can be observed in starlings, song thrushes, red kites, lapwing, skylark and blackcap.

For the actual long-distance migrants, who are genetically much more closely linked to their annual cycle, this can become a problem: Before they arrive in the breeding areas from Africa, the best nesting sites are often already occupied by the competition that has stayed at home.

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