Definitions of commonly used Bird Words
Antagonistic – Used to describe behaviors which are in opposition or conflict, especially between individuals.
Allofeeding – Behavioral event where one adult bird feeds another adult of the same species.
Allopreening – Behavioral event where one bird grooms another bird of the same species. Also known as allogrooming.
Altricial – A developmental classification of birds at hatching where young are relatively immobile, lack feathers or down, have closed eyes and are completely dependent on their parents for survival. Altricial birds include herons, hawks, woodpeckers, owls, and most passerine songbirds.
Anthropomorphism – Assigning human attributes or behaviors to non-human animals.
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.
Behavior – What an animal does, how it cares for itself and how it reacts to other organisms and the environment in which it lives.
Bill-sweeping – 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.
Bottomland – Low-lying land along a stream, river, or brook.
Breeding cycle – The time period beginning at nest building through egg laying and raising young to the point of independence.
Breeding range – The geographic area or spatial distribution in which a species is normally found breeding.
Breeding season – The period of time during each year when a species reproduces (mates and has young).
Brood (n) – The young of a bird that are hatched or cared for at one time.
Brood (v) – To sit on and keep warm (chicks).
Brooding – To sit on and keep young birds warm that cannot maintain their own body temperatures.
Brood parasitism – The act of laying eggs in the nests of other birds. The eggs are left under the parental care of the host parents which can be of the same or different species. Brown-headed Cowbirds are common brood parasites.
Brood patch – An area that develops on the lower abdomen of birds in which the feathers drop off and the skin thickens and becomes densely populated with blood vessels. Used in incubation to keep eggs and young warm. Also known as incubation patch.
Brood reduction – A reproductive strategy where the female lays more eggs than can be cared for and raised. The smallest and weakest of the brood typically starve or are killed by siblings.
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 or limb.
Cloaca – Posterior-most chamber of the digestive tract in birds and the point of contact during copulation.
Clutch – Total number of eggs laid by a female bird in one nest attempt.
Colony – A spatially discrete cluster of breeding territories, usually tightly packed together.
Competitor species – Any species, either avian or non-avian, that uses or attempts to use a nest site intended for a native nesting bird.
Coniferous – Consisting of evergreen trees such as pines, firs, and the like.
Conspecific – Of the same species.
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.
Contour feather – Predominate feather type found on the body, wings, and tail of the bird (as opposed to other feather types: down, bristles, semiplumes, etc.).
Cooperative breeding – Breeding system where non-parental adult birds assist other breeding pairs (usually their own parents) to rear offspring, instead of dispersing from the nest or breeding themselves.
Crèche – A flock of unrelated young brought together for protection, often guarded by a single parent bird, while other adult birds feed or rest.
Crepuscular – Active at twilight, dawn, and dusk.
Deciduous – Vegetation type where leaves fall off or shed either seasonally or at a certain stage of development in the life cycle.
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.
Dummy nest – One of several nests built to attract females, serve as shelter for juveniles, act as decoys for predators or serve as a back-up nest if the first nest is disturbed or destroyed.
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.
Ethology – The study of the behavior of animals in their natural environment.
Extra-pair copulation – Behavior in which a socially monogamous individual mates with an individual other than the one with which it has an established pair bond.
Fecal sac – A clean, tough mucous membrane containing the excrement of nestling birds.
Feeding – The act of providing food and nourishment to oneself or offspring.
Fledge (Fledging) – The act of leaving the nest or nest cavity after reaching a certain stage of maturity.
Fledgling – A young bird that left its nest.
Foraging – The act of searching for food.
Gape – The opening created when the mouth is opened wide; it is noticeably large in species that forage on aerial insects. In nestlings, often used to refer to the brightly colored areas in the corners of the open mouth. Brightly colored gapes may be retained by young birds after they leave the nest and thus can be used to determine the age of immature birds.
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.
Hibernation – Winter dormancy in animals characterized by a great decrease in metabolism.
Host – The bird/species whose nest receives eggs from a brood parasite such as the Brown-headed Cowbird. The host typically cares for the egg and unrelated young, even at the expense of its own offspring.
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.
Invertebrate – Members of the animal kingdom lacking a spinal column.
Irruption– A sudden large movement of individuals into an area where they are generally uncommon, often on an unpredictable basis; usually occurring because food supplies are low in the normal range.
Juvenile – A young bird, typically one that is recently fledged and has not attained its full adult plumage.
Larvae – The immature, wingless, and often worm-like stage of a metamorphic insect that hatches from the egg, alters chiefly in size while passing through several molts, and is finally transformed into a pupa or chrysalis from which the adult emerges.
Latitude – South to north measurement of location.
Lekking – Occurs in polygynous species, when males collect in a group to engage in courtship displays; females visit a lek for the sole purpose of mating.
Longitude – East to west measurement of location.
Migration – Regular, extensive, seasonal movements of birds between their breeding regions and their wintering regions.
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 can be 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 – Relating to, occurring, or active at night.
Open cup nesting – The tendency to nest in areas with little or no permanent enclosure, such as on trees, shrubs, herbaceous cover, 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.
Parasite – An organism that lives in or on an organism of another species (host) and derives its nutriment there from; usually a parasite causes some degree of damage to the host.
Parasite load – The amount or quantity of parasites possessed by an individual that may affect the individual’s capacity for survival.
Pellet – A mass of undigested materials such as fur, bones, and feathers regurgitated by predatory birds such as owls and hawks.
Penultimate – Next to the last, as in the penultimate egg.
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 general 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 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 leave the 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.
Riparian – Along banks of rivers and streams.
Roost (n) – A support on which birds rest; a place where birds customarily rest; also a group of birds resting together.
Roost (v) – To settle down for rest or sleep: perch.
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.
Siblicide – The death of a young bird usually as a result of fighting with siblings over food, common in years when food is in short supply.
Snag – A standing dead tree, and often a vital source of nesting sites for cavity-nesting birds.
Species – One of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring.
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).
Taxonomy – Scientific naming of organisms and their classification with reference to their precise position in the animal or plant kingdom.
Terrestrial – Living or growing on land.
Territory – A defended area of any shape or size that contains nest site and/or food resources; its boundaries may shift during the breeding season.
Thermoregulation – The act of maintaining a constant body temperature.