NESTS, NEST CONSTRUCTION, VARIATION IN NESTS BASED ON SPECIES Sort of an extension from Chapter 15, will want to know this information for Final. After this we’ll look at some nests (exercise here) and do statistics for project.

 Nests are used primarily for the raising of young  Incubation of eggs  Brooding of nestlings (altricial species)  There are a few species that build ‘dormatory’ nests for non-nesting purposes – we won’t worry about them  Monk Parakeets (Myiopsitta monachus) in New Orleans do this  There are a few species where males build display nests that aren’t used – we won’t worry about them  Carolina Wrens (Thryothorus ludovicianus) will do this  Focusing here on nests that are used during offspring production NESTS

 Birds lay eggs, eggs must be protected and incubated  Nest structure and location important  Guarding against nest predators  Guarding against nest parasites  Consistent incubation, may assist in temperature regulation NESTS Nest cup helps facilitate contact between female and eggs, nest content helps retain warmth

 Nest location and placement can vary strongly  From tree tops and rocky cliffs to underground or sitting on the water  Nest content can vary  Sticks/twigs, grass, mud, feathers, hair, bark  All this impacts nest microclimate  Strong evolutionary impact NESTS The Wrinkled Hornbill (Aceros corrugatus) is a cavity nester

NESTS – NOT REALLY A NEST? The Australian Brush Turkey (Alectura lathami) doesn’t build a classic nest, instead it’s a mound of rotting vegetation Development and nesting behavior of this species considered to be very primitive

NESTS – WATER BASED Pacific Loon (Gavia pacifica) nest above and Pied-billed Grebe (Podilymbus podiceps) nest at right Both cases nests are built of rotting materials (warmth?) and barely above the water (safety). Most loons and grebes build nests like this.

NESTS – GROUND NESTS Many species nest directly on the ground in nests that may be made of grass or twigs, sometimes just a scrape in the ground. Snowy Owl (Bubo scandiacus) nest at left and a Brown Pelican (Pelecanus occidentalis) below NOTE: big size differences in offspring

NESTS – GROUND NESTS Northern Harrier (Circus cyaneus) nest at above left, King Eider (Somateria spectabilis) nest lower left, Laughing Gull (Leucophaeus atricilla) nest below.

 Note that species that nest on the ground are often:  Large species  Colony nesters  Found in inaccessible areas  Cryptic in nature  Dangerous predators in their own right NESTS – GROUND NESTS Arctic Tern (Sterna paradisaea) Royal Tern (Thalasseus maximus)

Burrowing Owl (Athene cunicularia) Belted Kingfisher (Megaceryle alcyon) NESTS – BURROW NESTS Many cases the burrow was constructed by someone else, like a Gopher Tortoise

NESTS – CAVITY NESTS Many species use cavities, some are primary cavity excavators (like the Red-headed Woodpecker, Melanerpes erythrocephalus) while others are secondary cavity dwellers (like the Scarlet Macaw, Ara macao)

NESTS – CAVITY NESTS Great Horned Owl (Bubo virginianus) Eastern Bluebird (Sialia sialis) Prothonotary Warbler (Protonotaria citrea)

NESTS

NESTS - ARTIFICIAL Some species will readily accept man-made cavitities

NESTS - ARTIFICIAL Peregrine Falcons (Falco peregrinus) nest on open cliff faces, hunt in open areas. This has allowed them to adapt to human habitation and human supplied ‘cliff’ faces

NESTS Classic nest found in tree or shrub

 Materials used in nests can vary widely as well  Nothing (or next to it), just a ground scrape or a few sticks  Grass  Twigs, sticks, and bark  Mud  Construction can vary as well  Classic round nest shape  Hanging baskets  More exotic NESTS – MATERIALS Mourning Doves (Zenaida macroura) build surprisingly scanty nests for such a substantial bird

NESTS - SPECIALTIES Tailorbirds (Orthotomus sutorius) use a variety of grasses and plant fibers for the nest, and then have a unique construction

NESTS – SPECIALTIES Barn Swallow (Hirundo rustica) nests, above, are made of mud and feathers, Monk Parakeets (Myiopsitta monachus), right, use grass to build large nest colonies A swift nest made from saliva, will be used in bird’s nest soup

NESTS – SPECIALTIES Chestnut-headed Oropendola (Psarocolius wagleri) nests are finely woven structures Orchard Orioles (Icterus spurius) build a hanging basket type nest as well

NESTS  Most nests that one could see are going to be the stereotypical ‘nest’  Made of a collection of materials (grass, twigs, bark, hair, feathers  An outer heavier layer  An inner soft layer that provides insulation and cushioning  Habitat used by the adult often dictates what type of nest you will see Northern Cardinal (Cardinalis cardinalis) Eastern Meadowlark (Sturnella magna)

NESTS A precocial waterbird species like the Mallard (Anus patyrhynchos) can have a ground nest that is well camouflaged until hatching, then the hatchlings leave

 Nest success varies with latitude, nest location, and species size and offspring hardines s  Predation, starvation, adverse weather – big causes of nesting failure  Nest success also varies with type of nest  Cavity nesting species typically do better than open cup nesters, or ground nesters NESTS Song Sparrow (Melospiza melodia) nestlings