Biology Reference
In-Depth Information
Glossary
anting behavior.
The rubbing of ant bodies against the feathers or sitting on an anthill al-
lowing ants to crawl through the feathers. Ant bodies are covered with a bitter chemical
called formic acid, which may affordsome protection from mites and lice. People have re-
ported birds anting with items such as mothballs, cigarette butts, and onions.
aspect ratio.
How long a wing is compared to how wide it is. This determines how a bird
soars. High aspect ratios (long, narrow wings) allow flight at high speeds at low altitudes,
while being extremely maneuverable. Low aspect ratios (broader wings) are adapted to
slow speed, high altitude, effortless flight. Bird wings with aspect ratios at either extreme
make taking off from the ground without a stiff headwind difficult.
austral migrants.
BirdsthatbreedintheSouthernHemisphereandmigratenorthfortheir
winter.
brood parasites.
Birds that do not build a nest or care for their young directly, instead
searching out host nests in which to lay their eggs.
brood patch.
A bare spot on the belly or chest where a bird's body heat warms the eggs.
cloaca.
The opening chamber to the intestines, ureters, and sex organs.
contour feathers.
The outer feathers that keep moisture and wind out and streamline a
bird.
countersinging.
When neighboring birds sing in response to each other.
distraction display.
Feigning an injury with loud calls and drooping wings to draw pred-
ators away from the nest.
diurnal migrants.
Birds that migrate during the day.
down feathers.
The inner feathers that trap air, providing insulation to hold body heat in-
side.
generalists.
Bird species that can obtain everything they need from a variety of habitats.
gizzard.
A muscular chamber of the stomach that mashes the food.
glottis.
A fairly large opening on the bottom of the bird's mouth where the trachea begins.
guano.
The fecal and urinary waste of birds, especially seabirds, which contains a lot of
uric acid and is collected for nitrogen- and phosphorus-rich fertilizers.
innate behavior (also instinctive behavior).
A behavior that birds do in a particular situ-
ation without learning or trying that behavior beforehand.
indeterminate layer.
A bird that will continue laying more eggs for a long time if its eggs
are removed one by one.
