Biology Reference
In-Depth Information
incubates. Red-winged Blackbird males are brilliantly colored; in this species only the
crypticallycoloredfemaleincubates.Butboththedullycoloredfemaleandtheconspicu-
ous male Northern Cardinal and Rose-breasted Grosbeak incubate, and both sexes occa-
sionally even sing from the nest.
NOT AS EASY AS IT LOOKS
Incubating takes a tremendous amount of energy,
especially in cold environ-
ments. A female Snowy Owl, for example, begins incubating the moment she lays her
first egg, and if her mate is able to get enough food, she won't leave the nest at all for
manydaysatatime.Althoughtheylooklikethey'renotdoinganything,incubatingbirds
often lose weight during this period, especially if their mates are unable to bring them
sufficient food.
Q There is a Wood Duck house on the river near my cabin, low enough that I can
peek inside while I'm canoeing. Last year I watched the mother sitting on 12 eggs
for weeks — she always sat tight whenever I looked in. But then one day she was
gone and all the eggs were broken and looked like they'd been cleaned out. She nev-
er came back. What predator would have done this?
A
It sounds like your ducklings all hatched out! Ducklings call inside their eggs to syn-
chronize their hatching, and then when all the babies are dried off, they jump from the
nest and follow their mother to water, never to return unless one of them, as an adult,
choosesthatboxtonestin.Ifapredatorhadfoundthem,you'dhavefoundsignsofblood
and at least a few broken but unemptied eggs.
