ADVANCED LEC 17ORNITHOLOGY

University of Rio GrandeDonald P. Althoff, Ph.D.

ReproductionPart II

Reference Chapters 12 - 17

Which comes first…the egg or the nest?

• Thus far, have covered what the “laid” egg consists of…

• …but now how we got the egg being ready to be laid

• For those species that actually prepare a “nest”, they typically do so as the breeding/courtship process. This includes two phases: a) _________________= where b) _________________= what

Nest Site Selection• Many species are very selective. They spend days

finding the “spot”. For many species we’ve been able to quantity the apparent factors that result in placement. These include:

a) _________________—both at the macro and micro levels (including species &

density) b) _________________c) ___________________________d) _________________e) __________—if above groundf) __________ (edge, interior,

“scale-dependent”) g) _____________________________ e) etc.

Nest Site Selection…con’t• Some species take little time to

select a nest site. For example, some species of waterfowl may do what is referred to as “________ _________”. They simply use someone else’s nest. Ex. Wood ducks, redhead ducks, canvasbacks, ruddy ducks

• Many cavity nesters (i.e., _____________________ ) spend “no” time in nest preparation once cavity is identified…that is “excavating the hole”

↑ Wood duck “nest” in woodduck box…with over 25 eggs

Nest Building• Sex that chooses site: may be the Male, may be the

Female…may be both. ___________, though, it is the Female.

• Some species, like the marsh wren, it is the male that establishes the territory and builds several nests

vs.• Some species, like the red-winged blackbird that only

establishes the territory and therefore is dictating the general location of nests but not the specific site of the nest.

Nest Building…con’t• Some species: both sexes help

build (ex. _________ –the lightning bird) or use old nests (ospreys, hawks)

• ____________: male gets the sticks, the female weaves them in.

• ____________: female gathers nest material, them male builds the nest

Nest Types

• Buried underground

• Substrate

• Cavity (both primary and secondary)

• Elevated red-eyed vireo

prothonotary warbler

ovenbird burrowing owl

Nests: Buried Underground• Megapods (primitive family of

gallinaneous birds) bury their eggs either by covering them in sand or covering them with vegetation

• ___________: Nest first lined with “rotting” compost. Then covered with sand. ____ keeps nest temp at 330C (91.40F). Puts head into vegetation, sticks tongue out, and takes temp!

--long incubation period--young are

precoccial

sand

decaying veg

soil

Substrate Nests: ___ nesting material

• Nighthawks, whip-poor-wills (on rock, on “random” leaves)

• Tropical birds—lay eggs on ground

• Skimmers

• Numerous shorebirds

Substrate Nests: Nest material present

• “Dry”—ducks gather nesting material by ____________ from eventual nest site—do not gather and/or carry material…and line with feathers

(example: pintail)

• Some galliforms and swans also do this

Substrate Nests: Nest material present…con’t

• ____________—meadowlarks, grasshopper sparrows

• Often well-hidden…adult flies close to nest…then ‘walks’ the last few feet to it

Substrate Nests: Nest material present…con’t

• Floating nests—grebes, canvasbacks & redheads, ruddy ducks, some terns and loons (semi-floating)

common loon

western grebe

Cavity Nests• _______ cavities: rough-winged swallows,

kingfishers

• _______ cavities:a) _________—tree nesting ducks (wood ducks,

mergansers, buffleheads) b) _________ = excavated—woodpeckersc) __________ = already excavated—

chickadees, nuthatches, wrens, martins, owls

Cavity Nests: Red-cockaded Woodpecker• A species that is a

_______________• Construct their

own cavities… usually taking ____ _______________.

• Have ___________• Key design feature:

_________ around cavity causing tree to _______…which discourages snakes

Cavity Nests: Red-cockaded Woodpecker• __________________…so much attention has

been given to protecting habitat (80+ year pine stands—mostly longleaf pine)

• Have figured out “construction” details…so making some artificial cavities

http://www.talltimbers.org/ve-artificial-cavities.html -- video 33+ minutes

Elevated Nests

• ___ nesting materiala) fairy tern:

depression in tree branch b) palm swift: glues eggs to leaves,

usually palm leaves (uses saliva)

African palm swift

Elevated Nests…con’t

• Nesting material a) __________: mourning doves, herons,

cuckoos b) __________: opening at top; globular

4 types:

_____________—supported from below_____________—supported from the side_____________—supported from side and rim_____________—supported from top

Elevated Nest: STATANT

American robin

Elevated Nest: ADHERENTBarn swallows

Elevated Nest: PENSILECliff swallows

Elevated Nest: PENDULOUS

Baltimore oriole

Weaver finch

Elevated Nests… weaver finches

• Can tie ______________—and instinctive behavior pattern (see Gill Fig 15-9, p444)

• Pendulous nest has these advantages a) “___________” adaptation b) may be “_________” adaptation

Weaver finches: step-by-step construction

Ring Roof Egg chamber

Antechamber Entrance

Other Nest Types/Forms

• Colonial nests: social weaver from African savannah. 5-10 ft wide nests. Each bird with its own nest opening (like an apartment complex)

• Community nests: all females lay eggs in same nest. Example: ostriches

Cape cobra at a social weaver nest complex !

HornbillsNest in tree cavities. After clutch is laid, ________ goes inside. Male then fills in opening with mud, leaving vertical slit opening just wide enough for his/her bill to fit through. She stays insides during _____________________________…he feeds everyone through the slit