Glossary Archive - The Ornithology

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Albinism: A complete lack of melanin, producing white plumage and pink or red eyes.
Altitudinal migration: Seasonal movement up and down mountains rather than north and south.
Anting: Rubbing ants on the feathers, or lying on an ant nest, probably to control parasites.

Big Day: An attempt to record as many species as possible within one calendar day.
Bottleneck: A place where migrating birds are funnelled together, such as a strait, isthmus or mountain pass.
Brood parasite: A bird that lays its eggs in the nests of other species, which then raise its young.

Casque: A helmet-like growth on top of the bill or head.
Cere: The bare, often coloured skin at the base of the upper bill in raptors, parrots and pigeons.
Citizen science: Research in which volunteers collect data, such as eBird checklists or national bird atlases.
Coverts: Small feathers that overlap the bases of the flight and tail feathers, on both upper and under surfaces.
Culmen: The upper ridge of the bill from its tip to where the feathers begin.

Digiscoping: Taking photographs or video through a spotting scope with a camera or phone.
Dip: To miss a bird you went looking for.

Eclipse plumage: A dull, female-like plumage worn by male ducks for a few weeks after breeding.
Endemic: A species found naturally in only one area, such as a single country, island or mountain range.
Exit pupil: The width of the beam of light leaving binoculars: objective size divided by magnification.
Eye-ring: A ring of contrasting feathers or bare skin around the eye.

Fallout: Large numbers of migrants landing at once, usually when bad weather meets a migration.
Field of view: The width of the scene seen through binoculars, given in metres at 1,000 m or in degrees.
Flyway: The whole area used by a migratory bird population, from breeding to non-breeding grounds.

Geolocator: A tiny light-level logger that records day length to estimate a bird's location during migration.

Immature: Any plumage before a bird reaches full adult plumage.
Important Bird Area IBA: A site identified by BirdLife International as globally important for birds, using standard criteria.
Irruption: An irregular mass movement of birds beyond their usual range, often when food runs short.
IUCN Red List: The global assessment of extinction risk, with categories from Least Concern to Extinct.

Jizz GISS: The overall impression of a bird from its shape, size, movement and behaviour.
Juvenile: A young bird wearing its first set of true feathers, before its first moult.

LBJ: Short for "little brown job": a small brown bird that is hard to identify.
Lek: A display ground where males gather and perform to attract females.
Leucism: A partial loss of pigment that produces white or pale patches while the eyes stay normally coloured.
Life list: A running list of every species a birder has seen.
Lifer: A species you see for the first time in your life.
Line transect: A survey that follows a fixed route and records birds, often with their distance from the line.
Lores: The area between the eye and the base of the bill.

Malar stripe Moustachial stripe: A dark stripe running from the base of the bill down the side of the throat.
Mantle: The upper back, between the nape and the scapulars.
Mist net: A fine, almost invisible net used by licensed researchers to catch birds safely for ringing.
Mobbing: Small birds noisily harassing a predator such as an owl or hawk to drive it away.
Moult Molt (US): The regular replacement of old, worn feathers with new ones.

Patch: A local area that a birder visits regularly.
Philopatry: The tendency to return to breed at or near the place of birth.
Pishing: Making a "pssh-pssh" sound to draw small, curious birds out of cover.
Playback: Playing recorded calls or song to attract a bird into view.
Point count: A survey in which an observer records every bird seen or heard from a fixed point for a set time.
Primaries: The outermost flight feathers of the wing, attached to the "hand"; they provide most of the forward thrust.
Primary projection: How far the primary tips extend beyond the tertials on a perched bird.

Ringing Banding (US): Fitting a uniquely numbered ring to a bird's leg to study movement, survival and lifespan.
Rump: The lower back, just above the base of the tail.

Scapulars: Feathers on the "shoulder" that cover the join between wing and body on a perched bird.
Secondaries: Flight feathers along the "forearm" that form the inner trailing edge of the wing.
Sexual dimorphism: Differences in size or appearance between males and females of the same species.
Speculum: A bright, often iridescent patch on the secondaries of many ducks.
Spotting scope: A portable telescope, usually 20–60x, used for distant birds such as shorebirds and waterfowl.
Stopover site: A place where migrating birds rest and refuel on their journey.
Structural colour: Colour produced by the microscopic structure of feathers scattering light, rather than by pigment.
Supercilium Eyebrow: A pale stripe above the eye, often called the eyebrow.

Tarsus: The lower, usually bare, part of the leg above the toes.
Tertials: The innermost flight feathers, next to the body, which often cover the folded primaries on a perched bird.
Twitch Chase (US): To travel to see a rare bird found by someone else; a twitcher is someone who does this.