Birding Glossary

Altitudinal migrant

A bird that migrates vertically, spending different seasons at different elevations, but in the same geographical location.

Anterior

Forward, toward the mouth end. Also can be used as a direction, e.g. the mouth is anterior to the heart.

Birds of Prey

Birds of prey, or raptors, include the buzzards, eagles, falcons, hawks, harriers, kites, and owls – birds that kill animals for food or seek out animals that are already dead. They are mostly large and solitary birds, equipped with acute eyesight and hearing, sharp, hooked beaks and talons, and impressive flying ability. Most hunt by day but owls typically hunt by night. Many birds of prey have declined due to habitat loss, pollution, and hunting, but these beautiful birds are now protected, and many populations are recovering.

One of the most useful features for identification of the birds of prey is their shape which, along with their style of flight, can be quite distinctive.

Bilateral Symmetry

First, vertebrates (animals with backbones, including birds and people) have “bilateral symmetry,” literally this means “two sides look alike.” This means that you can cut a vertebrate in half from only one angle and get two (mostly) equal parts. Circles don’t have bilateral symmetry, you can cut a circle in half many different ways and get two full half circles. Generally bilateral symmetry is easy to see on the outside of an animal (we have two eyes, one on each side of the head, and so forth), but sometimes this is difficult to see with internal organs, but it’s generally true nonetheless.

Boreal Forest

The boreal forest is the ancient forest of the northern hemisphere, a mixed forest including many of the evergreens (spruce, fir, pine, larch). These species are well adapted to the long cold winters of the north, and create a dense forest with scant light or vegetation on the forest floor. The boreal forest is home to a multitude of plant and animal species, and is the summer breeding destination for many migrating birds. Much of the Earth’s boreal forest has been lost due to logging.

Breeding grounds

The habitat where a species nests and raises young.

Carrion

Carrion is the dead and decaying remains of an animal. Carrion, though repugnant to humans, is an important source of food for various other animals and insects that feed on it and aid in the decomposition process. Scavengers like vultures and hyenas are attracted to animals that are already dead. The type of carrion with which the majority of us in Western culture are the most familiar is road kill – animals killed on roads by automobiles and left to decay in the open.

Circadian rhythm

An internal clock that governs a bird’s daily cycle.

Circannual rhythm

An internal clock that governs a bird’s yearly life cycle, triggering breeding etc.

Crossbill

Crossbills belong to the finches (family Carduelidae, Genus Loxia) and are distinguished by a beak that crosses over itself at the tip. This awkward looking beak allows the birds to expertly remove the seeds from evergreen cones, their primary source of food. Four species of crossbills are found in Europe and two in North America, each with its preferred species of evergreen cone. The North American species are found primarily in Canada and in the mountainous areas of the United States.

Crane

Cranes belong to the family Gruidae; they are large wading birds, some easily as tall as a human, that breed in shallow wetlands. They feed on small animals, fish, insects, and plants. Most migrate to warm southern wetlands or grasslands for the winter. There are 15 species of cranes, more than half of which are endangered due to habitat loss and hunting. North America has two species, the endangered Whooping Crane, and the Sandhill Crane.

Though cranes and herons look quite similar, their manner of flight easily differentiates the two: cranes fly with their necks outstretched, while herons fly with their heads held back and their necks curved in an S shape.

Crown

The topmost part of the head. This is the area where you might find a crest on a cardinal or cockatoo.

Diurnal migration

Migration during the hours of daylight.

Dynamic soaring

A fight pattern where a bird glides with the wind until it drops too low, then climbs into the wing, turns and glides again.

Dorsal

The back, in most animals, the topmost side. In vertebrates this is the side closest to the spine. Also can be used as a direction, e.g. the backbone is dorsal to the heart.

Eagle

Eagles belong to the birds of prey, or raptors (family Accipitridae). They are expert flyers with keen eyesight to spot live prey below them, but they’ll also feed on carrion, particularly dead fish. In North America, congregations of hundreds of Bald Eagles can be seen in areas where food is plentiful, such as salmon rivers where fish die in large numbers after spawning. The Bald Eagle was endangered in the 1970’s due to widespread use of DDT; however, the population has rebounded significantly since the chemical was banned. Eagles have also been blamed for killing livestock, and their eggs and feathers have been coveted by collectors, contributing to the decline of many species.

Emu

The emu, family Dromaiideae, is a large flightless bird found only in Australia. Though it cannot fly, it moves quickly on sturdy legs. It is the only bird in its family – two species have been extinct since the early 1800’s, but today’s Emus are in no danger. Emus range across most of Australia eating mostly plants and migrating to new areas where food is abundant. They move in huge flocks and can demolish food crops very quickly, prompting the installation of many miles of fencing around agricultural lands.

Falcon

Falcons belong to the birds of prey, or raptors (family Falconidae). They are found everywhere on earth, except in the African rain forests and Antarctica. Falcons feed on insects and small animals, including birds smaller than themselves. They are recognizable in flight by their long tails, pointed wing tips and the habit of suddenly dropping into a dive when they spot prey below them. Most do not build nests but lay eggs in an abandoned nest, hollow tree, or a hollow in a cliff. Falcons have been trained for hunting (falconry) for hundreds of years.

Fall

When weather forces large numbers of migratory birds off course and they come down to rest somewhere that they do not normally occur.

Flyway

A route that many migrating birds of various species use while migrating. A flyway may be defined by a seacoast, a mountain range, a river system, an ocean current, or some other significant geographical feature that channels birds in flight.

Great Circle routes

Flight paths that represent the shortest distance between two points on the globe.

Gular Region

The area directly ventral to the bill. In pelicans this area is quite large and bare of feathers and forms a pouch. If a bird gets too hot, it may flutter the skin in the gular region to help cool itself, much like a dog pants.

Head

Anteriormost part of a bird, contains the bill (or beak), the eyes and the ears.

Irruption

When large numbers of one or more species of birds move together to new territory in search of food. is not true migration.

Lateral

To either side, left or right. Also can be used as a direction, e.g. the hand is lateral to the heart.

Leading lines

Physical features of the earth such as mountain passes, islands, and narrow necks of land that large numbers of birds must pass through or stop at.

Magnetic compass

The mechanism that allows a bird to navigate by locating magnetic north.

Migrant

A migrating bird.

Molt migration

A migration to a specific place where the birds molt.

Nonstop migrant

A bird that completes its entire migration without stopping along the way. Some nonstop migrations cover thousands of kilometers and span days.

Nocturnal migration

Migration during the hours of darkness.

Partial migration

When part of a population of birds in a specific area migrate while the rest remain resident year round. Sometimes, it is the juvenile birds that migrate.

Pineal gland

A gland in the brain that controls the circadian rhythm of bird species.

Posterior

Rearward, toward the tail. Also can be used as a direction, e.g. the tail is posterior to the heart.

Roost

A large number of birds, usually the same species, sleeping together in the same place.

Staging post

Stopovers where large numbers of migratory birds traditionally pause to feed before moving on. The best known staging posts are those used by large birds such as cranes.

Star compass

The mechanism that allows a bird to find its way by the location of the stars.

Stopover

A place where migrating birds stop to rest, shelter and feed. These are typically places with abundant food supplies.

Sun compass

The mechanism that allows a bird to find its way by the location of the sun.

Thermal current

Warm air rising into the atmosphere from the ground. Thermals are usually strongest in the morning.

Thermal soaring

When a bird uses the rising air of a thermal to lift it high in the air. The bird can then glide down to the bottom of the next thermal and rise again.

Ventral

The area opposite the dorsal, the belly region. In vertebrates, the side farthest from the spine. Also can be used as a direction, e.g. the heart is ventral to the backbone.

Wintering grounds

The territory where a bird species spends the winter months.

Zugunruhe

A restlessness observed in birds as approaches.