Birdwatching Glossary

If you are new to birdwatching, skimming through a field guide can sometimes be a little bewildering. What do all those strange words mean? Lores? Tertials? Wing bars?

Below we have compiled some of the birdwatching terms that you probably don’t use in everyday conversation. Can’t find the word you’re looking for? Let us know so that we can update this glossary.



  • Accidental: A bird that is found in a given area very infrequently and with no predictable pattern.
  • Auriculars (also called ear coverts): The patch of feathers that covers a bird’s ear opening.
  • Axillaries (also axillars): The small feathers on the underside of the wing near where it joins the body.
  • Big Year: A competitive event in which birders try to identify as many species as possible within a calendar year. Big Years may take place within a designated geographic area, such as a state or a continent, or they may be global.
  • Birding: Active (rather than passive) birdwatching. Birders deliberately hit the field to pursue their quarry.


  • Casual: A bird that is not found annually, but still at regular intervals.
  • Christmas Bird Count (CBC): An annual bird census held by the National Audubon Society between December 14 and January 5 and carried out by volunteers all across North America and in parts of Central and South America. Data from the CBC is used to monitor bird populations and distribution.
  • Confiding: Relatively tame; allowing humans to approach closely.
  • Crepuscular: Most active at dawn and dusk.
  • Decurved: Curving downward.
  • Diagnostic: Refers to a field mark that can positively clinch the identification of the bird in question.
  • Eclipse plumage: Dull plumage worn by males of some species, particularly ducks, for a short time after the breeding season. A male’s eclipse plumage usually resembles the year-round plumage of the female.
  • Endemic: A breeding species restricted to a specific geographical area.
  • Extirpated: Completely eliminated from a particular area, but present elsewhere.
  • Eye line: A line passing over or through the eye.
  • Eye ring: A circle of feathers around the eye, usually lighter than the surrounding feathers.


  • Field mark: A distinctive visual characteristic that is key to identifying a bird.
  • Hybrid: The offspring of parents of two different species.


  • Irruption: A sudden, dramatic southward migration of very large numbers of a given species in quest of food during the winter.
  • Juvenal: Plumage only seen on juvenile birds.
  • LBJ: Little brown job; i.e., a nondescript brown bird, usually a sparrow.
  • Leucistic: Displaying a partial loss of pigment, as evidenced by unusually pale coloring (dilute plumage) or abnormal patches of white (partial albinism).
  • Life bird (also lifer): A species that a birder has seen and identified for the very first time; not a repeat sighting. A life bird can be added to one’s life list.
  • Life list: A list of the species that a birdwatcher has seen in his lifetime.
  • Lores: The area between the bill and the eyes.
  • Malar: The area on the lower half of the face between the cheek and the throat.
  • Mantle: The upper back.
  • Melanistic: Displaying an unusual distribution of the pigment melanin, as evidenced by abnormally dark or black plumage.
  • Morph: A color variation within a species.


  • Ornithology: The scientific study of birds.
  • Passerine: A perching bird or songbird.
  • Patagial: Referring to the skin on the leading edge of a bird’s wing, specifically the part between the shoulder and the wrist.
  • Pelagic: Living out at sea, rarely seen inland.
  • Primaries: The long flight feathers near the tip of a bird’s wing.
  • Raptor: A bird of prey. Some birders prefer to use this term to apply specifically to diurnal birds of prey, such as hawks, as distinct from nocturnal birds like owls.
  • Rare: Found annually, but in small numbers.
  • Recurved: Curved upward.
  • Remiges: The stiff flight feathers of the wing.
  • Retrices: The stiff flight feathers of the tail.
  • Riparian: A habitat near a stream or river.


  • Scapulars: The row of feathers just above the wing when folded (the bird’s “shoulders”).
  • Secondaries: The medium-length flight feathers in the middle of the wing.
  • Speculum: A colorful stripe, usually with a metallic sheen, running across the secondaries.
  • Supercilium: The bird’s “eyebrow.”
  • Tarsus: The long, scaly part of a bird’s leg. (Note that a few species, such as the rough-legged hawk, have feathered tarsi.)
  • Tertials: The three flight feathers closest to the body.


  • Undertail coverts: Small feathers overlapping the upper surface of the long tail feathers.
  • Uppertail coverts: Small feathers overlapping the lower surface of the long tail feathers.
  • Vagrant: A bird found wandering outside of its normal range.
  • Vent: The area below the tail.
  • Wing bars: Strips of contrasting color running across the upper part of the wing when folded.
  • Wing coverts: Small feathers on the upper surface of the wing overlapping the flight feathers.