Insights into Nesting Behavior in Birds

Nests and Nesting behavior in birds By, G.Mallanagoud, Asst. Prof. Dept. of Zoology Veerashaiva College, Ballari, Karnataka.

NESTS & NESTING BEHAVIOR IN BIRDS Introduction: o Need of shelter for offspring among birds is more important because birds have to face maximum struggle with the environment and predators as they are warm blooded, oviparous and without defensive organs. o The parents of a family must find a shelter where the female can give birth to their offspring and get protection. Birds keep their species preserved by protecting their offspring (eggs and young ones) in many ways. o One of the most interesting methods to protect their offspring's is the nest building method. Nest provides protection and eggs are incubated and young nesting are reared. o Heat is essential for the incubation of eggs because the birds are warm blooded. The birds have instinct behavior i.e elaborate and skillfully built nest.

o Nests provide safety from predators and shelter from bad weather. o Nest is constructed by male or female or both. o There are many way to build the nest by using many materials. o Most of the birds construct different type of nest to hold the eggs during incubation and rearing of young ones. o During breeding season most of the parent birds and young ones faces danger from predators. o The eggs are sought by lizards, snakes, rats, squirrels, monkeys and man himself. o Even other birds are not to be trusted Crows and Gulls are notorious robbers.

Kinds of nests: Birds build crude nests depending on their needs. Birds usually construct a new nest annually where eggs are laid, incubated and young nesting are reared. Different kinds of nests are as follows. 1. Open-topped nests: Open typed nests are deep and cup-shaped structure helps to prevent the eggs or young ones from falling out. The birds are using different soft materials to construct the nest. Such as fibers, hair, wool and even fluffy feathers. Ex: Crow, Stork, Dove. They live in colonies or pairs and can defend them. Fig: open topped nests with eggs and bird

2. Covered nests: This type of nests is completely covered over by a domed roof. These nests have only a small opening on one side. The chamber is lined with small feathers or hairs. Fig: covered nests with eggs and young ones

3. Ground nest: • Pheasants, arboreal birds but they lay their eggs on lonely places of ground. • Cormorants, herons and ducks are aquatic birds but they make their nests in bushes near the water reservoir. • The shallow and bee-eater birds make horizontal tunnel in the ground and lay her eggs there. • Indian stone curlew lay their eggs on earth by removing some soil and making a ditch. • Singer sparrow and Towhee make two nests in two places in one season. First they make nest on ground and then in bushes. They can use only one nest for egg laying. • Lapwing usually make their nest in the bank of calm water reservoir, grazing ground and big gardens. Sometimes they also make nest on top of the building. • Female penguin makes hole in ice and lay her egg there. • Herring gulls built the nest on ground by using grasses and twigs. Partridges and curlews are Fig: Ground nests

4. Tunnel nest: Some Kingfishers, petrels, marmots etc., dig tunnel- like nest on the bank of the river and sea. They make chambers in those tunnels like nest. Fig: Tunnel nests in Kingfishers Fig: Tunnel nests Marmot

5. Birds excavated hollow holes in trees and other places: o Some species of kingfishers, and martins, bee eaters and few wood peckers make hollow nest in the trunk of the trees and use and use it as nest. o Eagle makes their nest in crevices of rock High Mountain. Other birds namely myna, parakeets, kingfishers and wood peckers built the nest in natural holes or cavities in the trees. Hole nests of Kingfisher Hole nest of wood pecker Hole nests of Martins Hole nests of Bee eater

6. Suspended nest (Pendent nest): o Baya weaver birds, tailor birds, sun birds and flower peck build pendant nest of compactly woven fibers. Oriole construct an intricate basket like nest using twig, thread etc., . o A tailor bird neatly stitches the edges of folded one or more large plant leaves with the threads of wool or cotton by means of its pointed beak. It is lined by soft fibers, cotton, wool and vegetables so that the nest becomes comfortable. o Male Baya make basket like nest having a long thin passage and a wide chamber. Half woven nest is like inverted basket. Female Baya selects male baya during half woven nest. After courtship male baya completes the nest. Old nest is abandoned by baya and make new nest every year. Fig: Nests of Baya, Tailor bird & Oriole

7.Floating nest: Jacana is an aquatic bird, make their nest on floating leaf. Mallard, grebes, moor hens and coots also make floating nests. Fig: Floating nest in Jacana

8.Walled nest: House martins and common swallow secrete cement like substance by salivary gland. They put this secretion on their feathers and make walled nest using cemented feathers. Fig: Walled nest of Martin & Common swallow

9. Birds do not make nest, incubate eggs on their body: o Few birds do not make nest but they incubate their eggs keeping them on the body. King penguins incubate their eggs keeping them on their legs. o The emperor penguin pushes single eggs below the fold of its belly. This fulfills the function of a nest. It is a method of incubating eggs in an unfavorable condition where there is only ice. Fig: Incubation of eggs by Penguins

NESTING BEHAVIOR IN WASPS: o Among the Wasps, the simplest nests consist of one more than burrows in the soil. o However, the preparation, provisioning and final concealment of these burrows involves a behavioral sequence i.e. truly fascinating to observed. o More elaborate nests are fashioned from a variety of natural materials and often are quite characteristic of the constructing species. o Number of Wasps species use mud for nest construction making many trips to fetch enough to build a nest suitable for a single offspring. o The time and energy devoted to the construction of these elaborate nests might seem to be an excessive from of parental care, however the resulting improved survival of young has clearly reduced the number of progeny each female needs to produce to assure survival of the species and thus permits some species to specialize on less abundant food sources. Fig: Nests of Wasps

NESTING BEHAVIOR IN SUNBIRDS: o Sun birds are small and measures about 9-25 cm in length. o The beak and tongue are reminiscent of those of humming birds. o The beak is long, thin tube-shaped and narrow right from the base. It is always pointed and black. o The tongue is long and its tip is projected formed into two tubes and is used for sucking up nectar or for catching arthropods. o In their reproduction, the sun birds pairs form for the whole breeding season. Both sexes are involved to construct the nest, and feeding of the young ones and thus monogamous in nature. o Usually the nest appears a pouch-shape and suspended from a branch. It is carefully held together by spider webs. The clutch usually bears two eggs. o Young cuckoo is being fed by the sunbirds. Fig: Nest of Sun bird

NEST BUILDING BEHAVIOR IN TAILOR BIRDS: o A tailor bird neatly stitches the edges of folded one or more large plant leaves with the threads of wool or cotton or spider web threads with the help of its pointed beak. o This funnel-shaped nest is ultimately lined by soft fibers, cotton, wool and vegetables, so that the nest become comfortable. o Then the bird searches the area for twigs and grass, which will make the floor of the nest and this cushion it deposits its eggs. o Tailor birds get their name from the way their nests are constructed. Nests are built with leaves that are pierced and stitched together with spider’s web or plant fibre. o The leaves are pulled together and stitched to form sort of a cradle where grass or other materials are placed within to construct the actual nest. Fig: Nest building behavior in long-tailed Tailor bird

NEST BUILDING BEHAVIOR IN BAYA: • Male Baya make basket like nest having a long thin passage and a wide chamber. Half woven nest is like inverted basket. • Female Baya selects male Baya during half woven nest. • After courtship male Baya completes the nest. Old nest is abandoned by Baya and make new nest every year.

Fig: Tailor bird Fig: Common tailor bird nest Fig: Common tailor bird collecting spider’s silk for its nest

NEST BUILDING BEHAVIOR IN BULBILS: o Bulbils shaped nest. The root fibers and twigs are used to construct the nest. The nest is hanging in the branches of bushy plants or trees. o The female incubates for 2-13 days. The male is responsible to bring the food occasionally relieves her. o Both parents feed insects to the young and male helps in covering them for warmth because the birds are homoeothermic in nature. o By the end of the first week the young ones are well feathered and they can leave the nest when 16 days old. build their open cup- Fig: Nest of Bulbils

NEST BUILDING BEHAVIOR IN HORNBILLS AND PARAKEETS: o The Hornbills and parakeet select the crevices of trunk of tree to use it as nest. Female hornbill or parakeet enters into the crevice of the hollow trunk of the tree. o Female lays the eggs to incubate them without leaving the nest. Male bring the food and provides to the female through the hole of nest. o The female cleans nest and passes out own fecal matter in force through the hole. o They paint the trunk of trees around the nest with the help of the gum of tree. o This gum makes the passage slippery and predator of birds i.e snakes can’t reach near the nest. Fig: Nest of Hornbill Fig: Nest of Parakeet

NEST BUILDING BEHAVIOR IN PIGEONS AND SPARROWS: o Pigeons and sparrows build their nests under the roof of the building. These birds using straw, grass, leaves, pieces of cloth, cotton, threads etc. to built the nest. o It is usually lined by the softer material, grass, tow, feathers etc. such nests are built in trees or on buildings. o In spring and summer season the birds use the nest for raising young. o The nest can be located in any available place in buildings, trees. o The nest building is done almost year around. o The nest is spherical in shape, 8 to 10 inches in outside diameter and is made of coarse material on the outside such as, straw, twigs, paper, leaves, grasses, and any other available material. o The inside is lined with feathers or fine grasses. o The female begins laying eggs about a week after nest building begins. o Typically 4 eggs are laid but some nest can have up to 7 eggs. o Incubation of the eggs is done by the female. o Incubation last for about 12 days and the young leave the nest in 15 to 17 days after hatching. o Both the male and female feed the young. After the young birds have fledged, the male continues feeding the fledglings while the female begins the next brood.

Fig: Nest of Pigeon Fig: Nest of Sparrow

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Insights into Nesting Behavior in Birds