Biology Reference
In-Depth Information
recordbuiltbysocialbirdswasanestmadebyAfricansocial-weavers.Thenesthad100
chambers. It was 27 feet (8.2 m) across and 6 feet (1.8 m) high.
NEST, SWEET NEST
When building a nest for the first time,
most birds seem to instinctively know what
materials to use and how to build it without having observed nest building before, per-
haps from having been raised in a particular kind of nest, but their skills improve with
age and experience. Some species, including turkeys, nighthawks, and Killdeer, make a
simple scrape in the ground, using their bellies to shape it. Others, such as orioles, con-
struct elaborately woven nests using hundreds of strands of grasses or fibers. There are
hundreds of ways in which birds construct their nests! Here are a few examples:
Peregrine Falcons
nest on ledges, cliffs, and inside special nest boxes with a gravel
bottom set out to attract them. The female doesn't bring any materials or make any ser-
ious efforts at construction; she merely lowers her belly and hollows out a little impres-
sion where she can lay her eggs, to keep them from rolling off.
Woodpeckers
build some of the most ecologically important nests, because they
provide roosting and nesting accommodations for many other animals after the wood-
peckers are done using them. A Pileated Woodpecker can hammer a hole about 2 inches
(5 cm) deep into hard wood with its bill. It can't hammer with any kind of power deeper
than that, because it can't align its body to have leverage, so Pileated Woodpeckers seek
out trees with healthy outer wood that are rotten on the inside. Male and female both
hammer a round hole wide enough to pass through, and then reach in to grab mouth-
fuls of the rotted woody matter and spit them out to excavate a nesting chamber inside.
During the nesting season, both parents incubate the eggs and then care for and feed the
young throughout the daytime; the male stays inside the nest with the eggs or chicks at
night.
Wood Ducks
alsodependoncavitiesbutcannotexcavatetheirown.WoodDucksoc-
casionallyuseoldPileatedWoodpeckerholes,butmoreoftenpreferholesformedwhena
rotten branch falls off a tree and heart rot creates a nest chamber. Wood Ducks don't col-
lect nesting materials, but the female does line the bottom with down feathers she pulls
from her breast and belly; they grow loose during the breeding season so this is easy for
her to do.
