Bird

A bird was a type of animal found on Earth and many other planets.

Birdie was named after his fondness for birds. (TV: Mutant Copper)

Birds were used by humans to study the effect of certain chemicals, as in the case of their use to test a new chemical weapon in 1943. (TV: The Curse of Fenric)

In 2013, the increased radiation, spread of silicon quartz in the water and the decline of local fish life resulted in the death of local bird populations, such as gannets, gulls and puffins. (AUDIO: Eldrad Must Die!)

In the epoch of Peri Brown, some species of birds were almost extinct. (TV: The Mark of the Rani)

When imprisoned inside his confession dial, the word "Bird" was used by the Twelfth Doctor to remind each copy of himself generated from the dial's hard drive to punch an azbantium wall blocking his exit from the dial. The Doctor got this idea from the Brothers Grimm's tale of a bird that chiselled away a diamond mountain by sharpening its beak on the mountain many times over hundreds of years. The Doctor remarked that it must have been "one hell of a bird". (TV: Heaven Sent)

Types of birds on Earth
Types of birds native to Earth included:

Beyond Earth
The First Doctor, John and Gillian visited a planet inhabited by giant birds which briefly captured them, but they escaped with the aid of an ugly animal. (COMIC: Kingdom of the Animals)

The Galyari revered birds. The Sixth Doctor used their birds to defeat Voshkar. (AUDIO: The Sandman)

The planet Pheros was inhabited by intelligent metal birds. (TV: The Infinite Quest) The devil-birds of Corbo were robots designed to resemble birds. (PROSE: The Devil-Birds of Corbo)

Birds existed on Gallifrey, two such species being the Trunkikes (PROSE: Blind Fury) and Snapping wart fowl. (AUDIO: The Next Life) A Dalek which had penetrated the sky trenches above Arcadia was briefly suggested by a Time Lord soldier to be a bird from the distance. (TV: The Last Day)