A Glossary of Ornithological Terms

Aberrant Abnormal or unusual Crown Upper part of head
Accidental Vagrant Crown-stripe Distinct line from forehead along centre of crown
Adult Mature, Capable of breeding Cryptic Hidden - having protective colouring and/ or behaviour
Aerial Making use of the open sky Culmen Ridge on upper mandible of bill
Allopatric Relating to two or more related species whose range do not overlap Cursorial Ground running
Altitudinal migrant Moving between high mountains and lower foothills Deciduous Trees that shed their leaves annually
Altricial Blind and helpless when hatched Decurved Curving downwards
Apical Outer extremities, particularly of the tail Diagnostic Sufficient to identify a species or subspecies
Aquatic Living on or in water Dimorphic Having two forms of plumage
Arboreal Living in trees Distal Terminal or the outer end
Ashy Greyish Colour Diurnal Active during daytime
Axillaries Underwing feathers at the base of the wings, forming ‘armpits’ Down Small soft feathers close to body of chicks
Back Loosely applied to the mantle scapulars and rump Drake Male duck
Banyan Type of fig tree Drumming Rhythmic territorial hammering on trees by woodpeckers
Barring ‘Sideway’ lines such as on tail or breast Duars Forested areas south of eastern Himalayas
Basal Innermost extremities, particularly of the tail or bill Ear-coverts Feathers covering the ear opening. Often distinctly coloured
Bheel Shallow lake or wetland Ear tufts Feathers protruding near ears
Biosphere The part of earth that is inhabited by life Echolocate Navigate by sound
Biotope Area of uniform environment, flora and fauna Eclipse Plumage New dull plumage after breeding season, especially in ducks
Bristles Sensory feathers near beak Endemic Indigenous and confined to a place
Brood Young hatched from a single clutch Endangered Species facing high risk of extinction
Brood Parasitism Depositing of eggs by one species in the nest of an another Eurasian Of both Europe and Asia
Buff Yellowish white with a hint of pale brown Evergreen Forests that always have leaves
Bund Man-made mud embankment Eye-ring Contrasting ring around the eye
Canopy Leafy foliage of treetops Eye-stripe Stripe through eye
Cap Upper part of head Extinct No longer in existence
Carpal Bend of a closed wing, sometimes called shoulder Extirpated Locally extinct
Casque Growth above bill of hornbills Extralimital Not existing in the region
Cere Patch of bare skin on upper base of bill of raptors Facial Disc Heart shaped arrangement of feathers as in some owls and harriers
Cheek Term loosely applied to sides of head, below the eye or on ear coverts Fallow Cultivated land after cultivation and before ploughing
Chevrons V-shaped contrasting marks on wings or bands across breast Family Specified group of genera
Cinnamon Light yellowish-brown colour Forage Search for food
Clutch Complete set of eggs laid by a single female Ferruginous Rusty-brown colour
Collar Distinctive band of colour that encircles or partly encircles the neck Feral Escaped, and living and breeding in the wild
Colonial Roosting or nesting in groups Filoplume Hair-like feathers like in breeding egrets
Confiding Not shy Flank Side of body
Commensal Living together with man for mutual benefit Fledged Having just acquired feathers and ready to leave nest
Coverts Small feathers on wings and base of tail Fledglings Young birds which have just acquired feathers
Covey Small group of partridges and allied species Flight feathers Primary and secondary wing feathers
Crepuscular Active at dusk (twilight) and dawn Flushed When disturbed into flight at close quarters
Crest Extended feathers on head Foreneck The lower throat
Crop Pouch-like enlargement of gullet in some  birds where food is partially digested Form Sub-species
  Frons Forehead