1. Avian Reproduction Nests, Eggs, and Chicks
With emphasis on differences in chick development

2. 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.

3. 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.

4. 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.

5. 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).

6. 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.

7. 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)

8. pendulous - nests suspended from the rims and sides; rather flexible and deep,
like those of orioles

9. 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)

10. 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.
Louisiana Waterthrush
Veery

11. Colonial nests of the Sociable Weaver – Protection from snakes (cobras)
Thermoregulation
Nesting associations with Pygmy Falcons

12. Lesser-masked weaver
white-browed sparrow weaver

13. Village Weaver, Ploceus cucullatus,
Weaving a single strip of elephant grass.
After Collias and Collias 1962.

14. Various knot types used by
Weavers

16. Tailorbird

17. Tits weave fragrant nests
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.

19. Camouflage in the Pied Monarch

20. (a) Lined forest falcon
(b) Hoatzin
(c) Great Antshrike
(d) Martins
(e) Woodpeckers
(f) Tityras
(g) Parakeets
(h) Sulphur-rumped
Flycatcher
(i) Little hermit

21. (j) Blue-crowned motmot
(k) Olive-backed foliage-
gleaner
(l) Bluish-fronted Jacamar
(m) Chestnut-capped Puffbird
(n) Starred wood-quail

22. Common Murre eggs
Blue Tit

23. Azure Kingfisher
Regent Bowerbird
Pied Oystercatcher

24. Parental Care:
Incubation/brooding
Feeding
Defense
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):

25. young are completely independent at hatching; no parental care
superprecocial
young are completely independent at hatching; no parental care
examples include young megapodes
Malleefowl

26. young leave the nest soon after hatching and follow parents
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

27. young leave the nest at hatching and follow parents
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

28. examples include young gulls and terns
semiprecocial
young are somewhat mobile at hatching but remain & are fed by their parents
examples include young gulls and terns
Common Tern

29. young not mobile at hatching & are fed and brooded by parents
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

30. young are naked, blind (eyes closed), & helpless at hatching
altricial
young are naked, blind (eyes closed), & helpless at hatching
examples includes songbirds, woodpeckers, hummingbirds, and pigeons

31. Summary of characteristics of young birds at hatching (Nice 1962):
Type of  Development
Down  present
Eyes  open
Mobile
Feed Themselves
Parents present
Examples
Superprecocial
Yes No
megapodes
Precocial
Yes (follow parents & find own food)
waterfowl, shorebirds
Subprecocial
Yes (may be shown food by parents)
grebes, rails, cranes, & loons
Semiprecocial
Yes, but remain in nest
gulls & terns, penguins
Semialtricial 1
hawks, herons & egrets
Semialtricial 2
owls
Altricial
songbirds