Words About Birds

Aquatic 
Living or growing in water.

Asynchronous hatching
Hatching that does not occur at the same time but that may take place over two to three calendar days.

Bill-sweeping
A display in which a pair of birds sweep their bills back and forth over the bark near their nest hole. Often the birds have crushed insects in their bills. Typical behavior of species such as White-breasted Nuthatch.

Breeding cycle
The time period beginning at courtship/mating through egg laying, and raising young to the point of independence.

Breeding season
The period of time during each year when a species reproduces (mates and has young).

Competitor species
Any species, either avian or non-avian, that uses or attempts to use a nest site intended for a native nesting bird.

Brood (n)
Young birds that are hatched or cared for at one time.

Brood (v)
To sit on and keep young birds warm.

Caching
The storage of berries, seeds, and other food items in the crevices of bark, under leaves, in cavities, and the like. Retrieval of cached food items is not accidental, as in scatterhoarding.

Carnivorous
Subsisting or feeding on animal tissues.

Cavity
A hole or opening in a tree trunk, limb, or other substrate.

Cloaca
Posterior-most chamber of the digestive tract in birds.

Clutch
The total number of eggs laid by a female bird in one nest attempt.

Contact call
A sound produced by a bird that appears to tell a nearby bird of the caller's location. For example, a mated male and female may make contact calls as they forage relatively close to one another.

Crepuscular
Active at twilight, dawn, and dusk.

Dimorphism
Existing in two forms, two color forms, two sexes, and the like.

Dispersal
The movement of a young bird from the site where it hatches to the site where it breeds (juvenile dispersal); the year-to-year movement of an adult bird from one nest site to another (breeding dispersal).

Diurnal
Of, relating to, occurring, or active in the day.

Ectoparasite
A parasite that lives on the exterior of its host.

Egg dumping
Occurs when a female lays her egg(s) in the nest of another bird, sometimes creating very large clutches, as is often the case for Wood Ducks.

Fecal sac
A clean, tough mucous membrane containing the excrement of nestling birds.

Fledge (fledging)
The act of leaving the nest or nest cavity after reaching a certain stage of maturity, even though flight may not yet be well developed.

Fledgling
A young bird that has recently left its nest and often is unable to survive on its own.

Foraging
The act of searching for food.

Generalist
In ornithology, a bird that uses many types of a resource. For example, it eats many different types of foods.

Granivorous
Feeding on seeds or grain.

Habitat
The place or environment where a plant or animal naturally or normally lives and grows.

Hatch
To emerge from an egg, pupa, or chrysalis

Hatching
The moment an organism emerges from an egg, pupa, or chrysalis.

Hatchling
A newly hatched bird or animal.

Helpers at the Nest
A form of cooperative breeding where juvenile or adult birds assist other breeding pairs (usually their own parents) to rear other offspring rather than dispersing from the nest or breeding themselves.

Hibernation
Winter dormancy in animals characterized by a great decrease in metabolism.

Incubation
The process by which birds keep eggs at the proper temperature to ensure normal embryonic development until hatching. In most cases, birds sit on eggs and transfer their body heat through a patch of skin known as the brood patch. In many species, only the female incubates; in other species, both males and females incubate. Less common, only the male incubates.

Incubation Period
The period of time during which adults (usually the breeder female) remain on the nest, using their bodies to keep the eggs warm and protected.

Insectivorous
Feeding on insects.

Mammal
Warm-blooded, higher vertebrates that nourish their young with milk secreted by mammary glands and have the skin usually more or less covered with hair; includes humans.

Migration
Regular, extensive, seasonal movements of animal populations between their breeding and wintering areas.

Monogamy
A common type of mating system found in birds. Socially monogamous birds have one mate that helps raise young, but they may actually have mated with more than one individual. Sexual monogamy implies mating of an animal with only one member of the opposite sex during the breeding season.

Monomorphic
Having a single form.

Natural cavity
A cavity created by natural means such as excavation by woodpeckers or formed by rot or insects and that is often used as a nest site by cavity-nesting birds.

Nest box
A box, typically made of wood, in which cavity-nesting birds can nest; also called a birdhouse.

Nestling
A young bird after hatching and before leaving the nest.

Nocturnal
Of, relating to, occurring, or active in the night.

Open-nesting
The tendency to nest in areas with little or no enclosure, such as in trees, shrubs, herbaceous cover, on the bare ground, or on a platform.

Pair bond
The association between two birds who have come together for reproduction; depending on the species, it can be short-term (lasting only through egg-laying or the rearing of young) or lifelong.

Penultimate
Next to the last, as in the next to last or penultimate egg laid.

Philopatry
Faithfulness to a region or an area.

Pip (v)
To break through the shell of the egg until hatched.

Polyandry
A less common form of polygamy where one female mates with several males.

Polygamy
A type of mating system found in birds where social bonds exist between more than one member of the opposite sex.

Polygyny
A common form of polygamy where one male mates with several females.

Precocial
Young that are capable of a high degree of independent activity immediately after hatching. Precocial young typically can move about, have their eyes open and will be covered in down at hatching. They are generally able to walk away from the nest as soon as they have dried off.

Predation
The act of preying or feeding on another living organism.

Preening
A type of avian grooming behavior where feathers are pulled or nibbled on in order to remove ectoparasites, and keep feathers healthy and waterproof. Many birds use oil from an oil gland above their tails, to spread on the feathers while they preen.

Premature Fledging
Nestlings abandon their nest before reaching the stage of maturity at which they normally fledge. Premature fledging may be caused by heat, parasites or disturbance by a predator or nest monitor.

Replacement Clutch
The eggs laid to replace a clutch in which none of the eggs hatched.

Residents
Individuals that live year round in a particular area.

Roost (n)
A support on which birds rest; also a group of birds resting together.

Roost (v)
To settle down for rest or sleep.

Scatterhoarding
Behavior in which birds hide food items in bark crevices and under leaves, moss, or lichen. Retrieval of food items is accidental, not memory-based.

Snag
A standing dead tree important for its soft wood that woodpeckers and secondary cavity-nesters can excavate for a nesting site.

Species
Related organisms or populations having common attributes and potentially capable of interbreeding.

Synchronous Hatching
Hatching that occurs at the same time or nearly the same time, usually within one calendar day.

Synchronous Nesting
Nesting by a local population in which breeding pairs initiate egg laying within a relatively short period of time (a few days to a few weeks).

Terrestrial
Living or growing on land.

Thermoregulate(ion)
The act of maintaining a constant body temperature.

Unbiased
Refers to estimates that are not always slanted in the same direction.