IL Birds of Prey -- Nests & Eggs
Nests and Eggs
Birds of prey have
several types of nesting strategies. The peregrine falcon is an example of a
species that does not spend any energy making a nest, but simply lays its eggs
directly on a high bluff or window ledge of a tall building. Screech owls and
American kestrels lay their eggs in the cavities of trees. The barn owl is appropriately
names because it often seeks its nest site in barns. The males of many species
collect sticks, feathers, leaves and mosses that the female uses to construct
the nest. Bald eagles reuse the same nest each year, adding branches, roots
and cornstalks. One bald eagle nest eventually weighed one ton!
Eggs are amazing!
They are strong enough to support the weight of their parents, who sit on the
egg while the chick develops. Strong as they are, they must be thin enough for
the hatchling to break out of the egg and join the world. Each egg has its own
special coloring and markings (like a fingerprint for a bird). The eggs of birds
of prey have muted colors to help them blend in with their surroundings (camouflage).
The number of eggs
laid in the nest is called the clutch. Clutch size is determined by nature and
how many hatchings can be successfully supported by the environment. The number
can be increased or decreased by the presence or absence of food, shelter, space,
water and competition.
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