Ornithology

thumb|A marbled godwit being ringed for studies on [[bird migration]]

seasonal movement of birds

species of bird

man-made enclosure for animals to nest in

thumb|alt=Old illustration, showing 23 birds' eggs of different size and colouring|Mid-19th century illustration showing the eggs of a number of bird species

proposed classification system of birds

large congregation of birds at a particular location

mode of locomotion used by bird species (assists birds while feeding, breeding, avoiding predators, and migrating)

thumb|The Rostocker Pfeilstorch, found in 1822, demonstrated that bird migration|birds migrated rather than hibernating or changing form in winter. A , ; plural , ) is a white stork that is injured by an arrow or spear while wintering in Africa and returns to Europe with the projectile stuck in its body. As of 2003, about 25 have been documented in Germany.

thumb|upright=.8|Fledging stage of the northern mockingbird (Mimus polyglottos) Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable condition in the nest, the nestling and fledging stage can be the same. For precocial birds, those that develop and leave the nest quickly, a short nestling stage precedes a longer fledging stage.

bird park near Walsrode, Germany

study of intelligence in birds

a formation in which its units are arranged diagonally

swarming behaviour of birds when foraging

BBC nature documentary series narrated by David Attenborough

thumb|250px|Yellow-faced honeyeater chicks

oil found in the proventriculus of some birds

device for trapping birds in

Ornithological data in map form

feeding behavior of plucking small prey from ground, foliage, or other surfaces

Wikimedia list article

thumb|Bird ichnology|Ichnofossil of a [[moa footprint from the Gisborne District, New Zealand]]

evolution of birds from non-flying ancestors