Glossary

albumen. Egg white

allopreening. Mutual preening

altricial. Describes chicks that hatch with sparse or no feathers, closed eyes, and no ability to leave the nest for at least a week or two

billing. Gently touching and grasping a mate’s bill

brancher. An owlet that leaves the nest and clambers along a branch before it is able to fly

brood patch, incubation patch. A bare patch of skin on a nesting parent’s belly that allows transfer of body heat to eggs or chicks

broody. Describes a parent bird’s instinct to incubate eggs

cache. To store food

call. A vocalization used year-round to maintain contact with the flock, give an alarm, or communicate within the nest, as distinct from the seasonal song, used for courtship and establishing territory

cloaca. The external opening of the oviduct

clutch. The total number of eggs laid in one nesting stint

cryptic. Colored for camouflage

determinate layer. A female that will produce a certain number of eggs and stop, even if one egg is removed

display. A behavior, characteristic of a species, used particularly by male birds in courtship or defense

egg tooth. A sharp point that develops on a chick’s beak while it is still inside the egg, used to break through (pip) the shell from the inside

feather tract. Row of follicles from which feathers will grow

fecal sac. The feces of a hatchling, enclosed in a tiny bundle easy for the parent to remove

fledging. The act of leaving the nest. Usually refers to altricial nestlings, when their eyes are open and they can hop or flit about. Also used to describe the time at which the young bird has finished acquiring its first full set of flight feathers, even though it may not yet be able to fly.

gape. The brightly colored interior of a songbird chick’s mouth

gular pouch. A throat sac that may be used for storing food while flying

heronry. A communal nesting area for herons

imprint. A hatchling’s instinctive memorization of its parent’s features

incubation patch. See brood patch

indeterminate layer. A female that continues laying, replacing any eggs removed from her nest

irruptive. Unpredictable in migratory behavior

mobbing. Grouping together to attack a predator

molt. To shed and replace feathers, usually seasonally

neotropical migrants. Birds that winter in American tropics and breed in North America

nuptial plumes. Specialized feathers displayed during courtship

obligate brood parasite. A bird that lays her eggs in another bird’s nest rather than building her own

oviduct. The passageway the egg follows from the ovary to the outside of the body

pinfeathers. Newly emerged feathers that are still enclosed in sheaths

pip. To break a small hole in the shell of the egg, from the inside out

polygynous. Describes a male simultaneously paired to more than one female

precocial. Describes chicks that hatch covered with down, with eyes open, able to follow their parents away from the nest

semi-precocial. Describes chicks that hatch covered with down and with open eyes, but not as mobile and independent as precocial chicks

shaft. A feather’s thick central stem

sky dance. An aerial courtship display

song. A vocalization used seasonally, primarily by male birds, for courtship and establishing territory, as distinct from the year-round call

squab. A baby pigeon or dove

talons. A raptor’s feet, used for grasping

Bird Anatomy