Avian Reproduction Nests, Eggs, and Chicks With emphasis on differences in chick development
Dec 23, 2015
Avian Reproduction
Nests, Eggs, and Chicks
With emphasis on differences in chick development
Scrape nests are simple depressions in the ground (sometimes with a few stones added) or in the leaf litter. Such nests are used by some penguins, shorebirds, gulls, terns, nighthawks, vultures and other species.
Burrow nests are very effective at protecting eggs and young from predators & maintaining an appropriate microclimate for eggs & young. Some birds, like Bank Swallows and Belted Kingfishers (pictured below), usually construct their own burrows, while others, such as Burrowing Owls, may use burrows constructed by other species.
Cavity nests (e.g., in trees or cacti) are used by numerous passerines, woodpeckers, owls, parrots, and some waterfowl. Some birds, such as woodpeckers, construct their own cavity nests and are referred to as primary cavity nesters. Species that use natural cavities or cavities constructed by primary cavity nesters are called secondary cavity nesters.
Platform nests are relatively flat nests that may be located on the ground, in a tree, or on the tops of rooted vegetation or debris in shallow water like the Western Grebe nest below).
Cupped nests are, of course, cup-shaped. Such nests may be constructed of various materials and in a variety of locations. Pettingill (1985) categorized cup nests as follows:
statant cupped nests - nests located in the crotches and branches of trees and shrubs and supported mainly from below. Many passerines and hummingbirds build such nests.
suspended cupped nests - nests not supported from below but from the rims, sides, or both:
pensile - nests suspended from the rims and sides; rather stiff, e.g., those of kinglets and vireos (like the Black-capped Vireo pictured below)
pendulous - nests suspended from the rims and sides; rather flexible and deep, like those of orioles
adherent nests - cupped nests whose sides are attached by an adhesive substance (e.g., mud or saliva) to a vertical surface, like those of swifts and some swallows (see Barn Swallow nest below)
ground nests - cupped nests on the ground; sides are sometimes extended upward and arched over the top making a domed structure. Several passerines, particularly those that occupy open habitats like grasslands and tundra, build ground nests.
Veery Louisiana Waterthrush
Colonial nests of the Sociable Weaver – Protection from snakes (cobras) Thermoregulation Nesting associations with Pygmy Falcons
Lesser-masked weaver
white-browed sparrow weaver
Village Weaver, Ploceus cucullatus,Weaving a single strip of elephant grass.After Collias and Collias 1962.
Various knot types used by Weavers
Tailorbird
Tits weave fragrant nests. - Birds weave aromatic plants into their nests, apparently to keep their home clean and bug-free for raising chicks. Blue Tits on the fragrant Mediterranean island of Corsica can even smell when it's time to refresh fading fragments, ecologists have shown (Petit et al. 2002). Female blue tits gather lavender, yarrow, curry, mint and other scented plants for their nests shortly after laying eggs, and continue to do so until the chicks leave home. "They are real botanists and do a great job exploiting their environment to protect their chicks," says Marcel Lambrechts of the Centre for Functional Ecology and Evolution in Montpellier, France. The birds make a pot-pourri of 10 aromatic plants from the 250 species in their habitat. Many of the chemicals in these plants ward off bacteria, viruses, parasites, fungi and insects. Lambrechts's team removed the aromatic plants from 64 nests and then placed a hidden box containing lavender and yarrow underneath half of the nests. In the first 24 hours, only the birds with empty boxes replenished their herb supply. After 48 hours, the other half of the birds began to restock too, as the scent from the hidden herbs waned. "This field test directly shows that birds are attending to odour cues," says Larry Clark, who studies similar behaviour in European Starlings at the National Wildlife Research Center in Fort Collins, Colorado. The Blue Tits select for chemical diversity as well as high concentrations of chemicals, he points out, underlining the importance of olfaction in avian behavior.
Camouflage in the Pied Monarch
(a) Lined forest falcon(b) Hoatzin(c) Great Antshrike
(d) Martins(e) Woodpeckers(f) Tityras(g) Parakeets
(h) Sulphur-rumped Flycatcher
(i) Little hermit
(j) Blue-crowned motmot ((k) Olive-backed foliage- gleaner
(l) Bluish-fronted Jacamar
(m) Chestnut-capped Puffbird
(n) Starred wood-quail
Common Murre eggs Blue Tit
Regent Bowerbird
Azure Kingfisher
Pied Oystercatcher
Parental Care:
Incubation/broodingFeedingDefense
At hatching, some young birds are entirely dependent on their parents, while others are able to leave the nest and begin finding their own food within hours of hatching. Based on such differences, young birds are generally categorized as either altricial or precocial. Because of variation within these two broad categories, ornithologists more precisely classify young birds into six categories (Gill 1995):
superprecocial young are completely independent at hatching; no parental care
examples include young megapodes
Malleefowl
precocial young leave the nest soon after hatching and follow parents
young can feed themselves almost immediately examples include young waterfowl, shorebirds, and gallinaceous birds
Dunlin
subprecocial young leave the nest at hatching and follow parents
young are fed by parents (or at least shown where food is located by parents) examples include young rails, grebes, & loons
Eared Grebe
semiprecocial young are somewhat mobile at hatching but remain & are fed by their parents
examples include young gulls and terns
Common Tern
semialtricial young not mobile at hatching & are fed and brooded by parents
eyes of young open at hatching (semialtricial 1) or within a few days (semialtricial 2, e.g., owls )
examples include young herons, hawks, & owls
altricial young are naked, blind (eyes closed), & helpless at hatching
examples includes songbirds, woodpeckers, hummingbirds, and pigeons
Summary of characteristics of young birds at hatching (Nice 1962):
Type of Developmen
t
Down present
Eyes open
MobileFeed
ThemselvesParents present
Examples
Superprecocial Yes Yes Yes Yes No megapodes
Precocial Yes Yes YesYes (follow
parents & find own food)
Yeswaterfowl, shorebirds
Subprecocial Yes Yes YesYes (may be shown food by parents)
Yes
grebes, rails,
cranes, & loons
Semiprecocial Yes YesYes, but remain in
nestNo Yes
gulls & terns,
penguins
Semialtricial 1 Yes Yes No No Yeshawks,
herons & egrets
Semialtricial 2 Yes No No No Yes owls
Altricial No No No No Yes songbirds