bird nest

The large nest of the storks is also called the eyrie.

The bird nest , which birds create or renovate during the breeding season, is a species-typical construction that is supposed to ensure the survival of the offspring. The term eyrie has established itself for a large nest like the one built by white storks or hawks .

Nesting place

Floating nest of a white rail

Birds build a more or less complex nest out of various materials in order to hatch the eggs in a protected area and to care for their young. The constructions are very different from type to type, but not only the architectures differ, but also the location. High up in the treetops, for example, magpies , hawks and originally white storks lay their nests. On the ground, for example, lapwing and ringed plover breed in a shallow hollow with no real nest . Many small songbirds breed in the herbaceous layer above the ground and in the bushes.

Some bird species build their nests directly on the water by laying dry stalks and aquatic plants criss-cross on top of each other. Such floating nests as the great crested grebe and the Blässrallen . Other species create breeding tunnels in the more or less loamy steep bank, including the bee-eater and sand martin . Then there are species of birds such as the various species of woodpecker that breed in tree hollows.

Nest types

There are various attempts to categorize bird nests according to their shape or layout. The main nest types in the bird kingdom are easy to distinguish:

Platform: with loosely packed material on land or water; as with swans , pigeons, and herons ;
Nest hollow: with a dug out, which is padded with feathers or plant material; common in geese and duck species ;
Cup-shaped nest: made up of interwoven plant fibers; common with many songbirds;
Tree hole: mainly in old trees; known from woodpeckers, tits , nuthatches and owls ;
Earth cave: in the form of a tube in sand and clay pits; as with bee-eaters, kingfishers and sand martins;
Haufennest: built from muddy earth and with a hollow; typical of flamingos ;
Ball nest: with dome or complex woven; as with wren , tail and bag tits and weaver birds ;
Clay nest: made of earth and slime, it sticks to a rock or house wall; typical of swallows , nuthatches and common swifts .

Nest building techniques

Braided nest of a weaver bird

Clay nest with entrance tube of a cliff glue on the house wall (Armenia)

Ground brooder nest ( robin )

The founder of German ornithology, Johann Friedrich Naumann , had a special perspective on the bird's nest, and he emphasized the activity of birds. He differentiated the following groups according to their craftsmanship and skill:

Miniature birds that “dig holes with more or less horizontal passages on steep banks or sand and clay walls or widen crevices in the rock…” Examples: sand martin , kingfisher, bee eater

Erdnister who "usually only prepare a very artless nest directly on the ground, often only using a shallow recess [...]." Examples: skylark , lapwing, black-headed gull

Bricklayers who "build their nests out of clay and earth, which they put together when wet in the manner of building craftsmen ...". Examples: flour and barn swallow , Flamingo

Carpenters or Meissler that "with its beak in trees be worked out caves and Nistlöcher." Examples: woodpeckers and other woodpeckers, Wendehals

Platform builders who “create flat nests for themselves from brushwood and branches.” Examples: white stork, gray heron and some species of eagle

Basket makers or weavers who “very loosely weave their nests, which are usually clearly deepened, from thin or thicker, mostly dry stems.” Examples: thrushes and bunting , great crested grebes

Weavers who "carefully create a network of mostly very thin stalks, sheep's wool threads and other hair from horses, cows [...]." Examples: robins , goldhamers , redstart

Felt makers or felters who “use animal and plant wool to felt together other fine building materials into a dense mass.” Examples: chaffinch and goldfinch

Glue artists or putty makers who "glue small building materials together with a glue-like adhesive that they separate." Examples: Common swifts (lining the nest) and their distant relatives ( tribe of the Salangans )

Vault builders who "usually arch the nest upwards with leaves and moss ..." Examples: wren, tailed tit

Tailors , "who make their nest by sewing leaves together." Examples: the so-called tailor birds ( Orthotomus species that are not common in Central Europe)

Wallnisters or shovels who “embed the eggs in a large pile of decaying leaves or other parts of the plant [...].” Example: Australian thermometer chicken

Naumann knew that his classification was not clear and that some bird species can be assigned to one or the other group. He also added that some species share the nests of other species in the form of a breeding community - sparrows often nest in stork nests - and other species are veritable brood parasites . The best-known example is the cuckoo , which neither builds a nest nor hatches its own eggs and does not feed its young.

Artificial nests

Nesting aids for sparrows on a house facade (Belarus)

Since many people enjoy birds - also as messengers of spring or happiness - or value them as insect killers, they attach nesting pads, simple nesting aids or nesting boxes in gardens or on their houses. Some are simply constructed and self-built, others are fashionable.

Functions of the nest

The construction and properties of bird nests are subject to natural selection . To a certain extent, they ensure the survival of the offspring, i.e. the genetic material of the parents, by ensuring the safe and successful development of eggs and young birds and at the same time serving to protect the adult birds physically.

A location is usually chosen for the nest where the breeding site and the young birds are well camouflaged and as safe as possible from predators from the air and on the ground.

Wherever birds build a nest, food is usually not far away either: Ospreys breed in trees by bodies of water where they can fish, starlings often in gardens, where they can find and feed all kinds of berries in addition to insects.

The climatic conditions also have to be right. This is why nests are more likely to be found in a comparatively cool place in an arid environment , while for other species, such as the eider on the seashore, it is advantageous to use a sheltered place.

Parasites easily spread in bird nests . Parents of birds ensure hygiene by transporting the ball of excrement out or by adding aromatic plant material with a biocidal or antimicrobial effect . In the case of the white stork, it is easy to observe that the young storks defecate over the edge of the nest.

However, there are also functions of nests that go beyond the purpose of safely raising young. Because sexual selection is not limited to the future partner being of a strong stature and e.g. singing persistently or effectively driving rivals to flight, but external attributes such as a stable woven nest can also convince a female weaver bird of a certain partner. Behind this is the idea of the " extended phenotype ".

Division of labor in nest building

House martins build together or take over an artificial nest

Whether and with how much effort the male or female birds take part in nest building is above all a question of species affiliation. Often the partners build together, then the male often brings in suitable nesting material, while the female is to a certain extent responsible for the arrangement and interior construction. In some bird species, the females build all alone, in others the males. Here are some examples from the local bird world:

The house swallow and the barn swallow build together . Even with carrion crows , magpies and jackdaws , building is done in partnership - with the division of labor in some cases: the males are primarily carriers of nesting material. Also mute swan and white storks build together. The house sparrow and the tree sparrow are extremely equal.

It is typical for some of the finch birds that only the females build : greenfinch , goldfinch, chaffinch, girlitz etc. However, they are accompanied by their partner, that is, he is present. Female blue tits and the great reed warbler and reed warbler are left to their own devices when building their nests .

With some bird species , the males start building nests on their own and then continue their activity when a female bird is interested in them and the system. So it is with the bag tit , where the couple then continue building together as soon as the nest and partner have been accepted by the female. Otherwise, the male will start a new nest elsewhere.

Nest building behavior and sexual selection

Studies have shown that female bag-titans prefer larger nests over smaller ones and that they make an increased investment in brood care . In the wren, the male builds one or more nests. Once a female has made up her mind, she pads the future brood nest with feathers. Both bird species are considered classic examples of the nest functioning as a signal for the male partner's fitness; in the sense of sexual selection and in line with the concept of the extended phenotype.

For a number of years there has been a discussion about the contradiction between natural and sexual selection for the optimization of nesting structures: In some species, voluminous nests are more attractive for females - and thus the builder. On the other hand, natural selection favors small nests, as they are, for example, less conspicuous for predators and can be constructed with less effort.

Individual evidence

^ Josef Helmut Reichholf: Ornis . 1st edition. CH Beck, Munich 2014, ISBN 978-3-406-66048-1 .
↑ Michael Wink: Ornithology for beginners . 1st edition. Springer Spectrum, Heidelberg 2014, ISBN 978-3-8274-2324-5 , p. 249 .
^ Elke Brüser: Distant builders. In: flapping wings and quiet step. June 15, 2018, accessed November 15, 2019 .
↑ Johann Friedrich Naumann: Natural history of the birds of Central Europe . Ed .: Carl R. Hennicke. 3. Edition. tape 1 . Gera-Untermhaus, 1897, ISBN 978-3-7434-5768-3 , p. 104 .
↑ Bernd Leisler, Messages from the Bird's Nest , Vogelwarte 54, 2016, 109–124
↑ ^a ^b ^c ^d Mark C. Mainwaring u. a .: The design and function of birds' nests . In: Ecology and Evolution . tape 20 , no. 4 , 2014, p. 3909-3928 , doi : 10.1002 / ece3.1054 .
↑ ^a ^b Wolfgang Makatsch: The bird and its nest . In: The New Brehm Library . tape 14 . Academic publishing company Geest & Portig K.-G. with A. Ziemsen Verlag, Leipzig / Wittenberg 1951, ISBN 978-3-89432-510-7 .
↑ Bernd Leisler: Bird nests are multifunctional buildings . In: The falcon . tape 63 , no. 6 , ISSN 0323-357X .

[1] Josef Helmut Reichholf: Ornis . 1st edition. CH Beck, Munich 2014, ISBN 978-3-406-66048-1 .

[2] Michael Wink: Ornithology for beginners . 1st edition. Springer Spectrum, Heidelberg 2014, ISBN 978-3-8274-2324-5 , p. 249 .

[3] Elke Brüser: Distant builders. In: flapping wings and quiet step. June 15, 2018, accessed November 15, 2019 .

[4] Johann Friedrich Naumann: Natural history of the birds of Central Europe . Ed .: Carl R. Hennicke. 3. Edition. tape 1 . Gera-Untermhaus, 1897, ISBN 978-3-7434-5768-3 , p. 104 .

[5] Bernd Leisler, Messages from the Bird's Nest , Vogelwarte 54, 2016, 109–124

[:0-6] Mark C. Mainwaring u. a .: The design and function of birds' nests . In: Ecology and Evolution . tape 20 , no. 4 , 2014, p. 3909-3928 , doi : 10.1002 / ece3.1054 .

[:1-7] Wolfgang Makatsch: The bird and its nest . In: The New Brehm Library . tape 14 . Academic publishing company Geest & Portig K.-G. with A. Ziemsen Verlag, Leipzig / Wittenberg 1951, ISBN 978-3-89432-510-7 .

[8] Bernd Leisler: Bird nests are multifunctional buildings . In: The falcon . tape 63 , no. 6 , ISSN 0323-357X .