Friday, May 18, 2012

Birds Mom Awards: The Good, the Bad, and the Just Plain Weird

Mother birds employ wildly different reproductive strategies, nearly all of them successful. From a human point of view, however, some moms seem “better” than others. Here are the National Audubon Society's first-ever “Mother Hen Awards” for distinctive parenting styles, just in time for Mother's Day.

1) Best Bird Mom: Osprey
Osprey mothers take parenting seriously. They do most of the incubation and care for the hatchlings for weeks after they appear. Ospreys are famous for aggressive defense of their nests. Researchers venturing too close to a nest report harrowing near misses from osprey talons. Mom and the chicks dine mostly on fresh fish, caught daily and delivered by dad.
Clutch size: 2-4

A least tern parent (males and females look the same)
feeding a fish to a small chick near St Augustine, Florida.
Photograph: Craig ONeal/CC-by-2.0
2) Coolest Bird Mom: Least Tern
Least Terns are beach breeders, generally nesting in a scrape of sand or pebbles just above the high tide line. On warm days Tern moms will stand over eggs and hatchlings to shade them from the sun. On hot days, mother terns will soak her belly feathers in the ocean and return to give her brood a cool sponge bath.
Clutch size: 1-3

3) Martha Stewart Award: Prothonotary Warbler
Although warbler dads select the nest site—typically a low cavity in trees typical of bottomland or swamp forests—mother warblers assume the heavy-duty homemaking, and they take their responsibility seriously. Warbler moms will spend as many as eight days constructing and outfitting the nest. They build layer upon layer of soft material using a variety of mosses, leaves, and even fishing line when they can find it.
Clutch size: 3-7 eggs

Female Wilson’s phalarope (males are duller in color).
Photograph: Dominic sherony/CC-by-2
4) Flightiest Mom: Wilson’s Phalarope
These aquatic sandpipers are well known for their avian role reversal: Dads provide all the parental care. After a female lays her first egg in a scrape, the male picks up where she left off, arranging vegetation in and around the scrape. Fathers also incubate and provide for the brood, their (temporary) mates having deserted the family upon finishing their egg-laying.
Clutch size: 3-4

Female cowbird.
Photograph: ibm4381/CC-by-20

5) Laziest Mom: Brown-headed Cowbird
Mother cowbirds outsource the job—by laying their eggs in the nests of other birds. More than 200 species, including red-winged blackbirds, yellow warblers, and red-eyed vireo, are unwitting surrogate moms for these chicks. Some species keen to the cowbird’s plan build over her eggs or boot them out of the nest, but most simply don’t know what’s happened until the cowbirds hatch. Surprise!
Clutch size: For brown-headed cowbirds, the idea of a “clutch size,” doesn’t really apply, according to bird expert Kenn Kaufman. A host's nest might have more than one cowbird egg in it—likely from multiple females. During the breeding season, a female brown-headed cowbird may lay up to 40 eggs (not all in one nest).

Barn swallows. Photograph: Ben Knoot

6) "Group Effort" Mom: Barn Swallow
Raising young Barn Swallows sometimes takes a village, with both extra adults and older siblings serving as mother’s helpers. Virtual “aunts” and “uncles” assist in nest-building, incubation and brooding—and defend the nest by mobbing predators. Big brothers, sisters, and older “cousins” help out by feeding insects to the baby chicks. Cup-shaped mud structures lined with grass and feathers, Barn Swallow nests are often built on man-made structures like eaves, rafters and cross beams in sheds and stables.
Clutch size: 4-5

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