Bird
A bird was an endothermic feathered lifeform found on many planets.

Biology
The anatomy of birds was characterized by having a coat of feathers, wings, a beaked mouth, and feet with claws/talons. 

During a visit to the Sky Spirits' homeworld by  in 2372, Neelix was attacked by a , which by either using its beak or claws, gouged him near his left eye. Following an emergency transport to Sickbay, The Doctor informed Neelix that "You're very lucky this bird didn't snatch your eye right out of the socket. We have no spare Talaxian eyeballs. ()

Many birds were capable of flight, reproduced by laying eggs, and typically built and lived in nests, or artificially built birdhouses. When Tom Paris was a kid, a baby bird fell from its nest onto the windowsill next to his bed. According to Paris, "We had to feed it water with an eye dropper to keep it alive." () 

Birds communicated by means of bird calls. Simulated bird calls were often used on holodecks or other forms of media as background noise. (; ; ; )

Terminology 
The term avifaunal lifeform referred to the total of all bird species on a planet. In 2366, when Data overheard the phrase "early bird gets the worm", he observed that there was no evidence of avifaunal or crawling vermicular lifeforms on Jouret IV. ()

The study of birds was known as ornithology. The term ornithoid referred to something that resembled a bird or was bird-like. In 2367, Data stated that he was possibly "pursuing an untamed ornithoid without cause", meaning on a "wild goose chase." () 

"Bird" was one of the words Miles O'Brien used due to his infection of the aphasia virus in 2369. ()

The idiom "the birds and the bees" was meant to refer to courtship and sexual intercourse. When Captain Kirk and Commander Spock were discussing Vulcan mating rituals, Kirk remarked that there was no need to be embarrassed about it and that it would also happen to "the birds and the bees". Spock logically responded that "the birds and the bees are not Vulcans". () Following the close encounter between Harry Kim and Derran Tal, they discussed the unexpected experience they shared, and despite their similar appearances on the surface, how different things were when it came down to the basics, "let's just say the birds and bees would be very confused." ()

History
Bird-like creatures could be seen flying across the skies of Risa, Mintaka III, Tarok, and an unidentified planet in the Delta Quadrant. (; ; )

In 2267, Lieutenant Esteban Rodriguez and Captain James T. Kirk, while having shore leave on the Shore Leave Planet, separately saw a flock of birds in the sky. This was despite surveys of the planet having shown there to be no animals on the planet, since, as it ultimately turned out, these and other sights were instead accomplished robotically. ()

Major Kira Nerys told Mullibok a story from her childhood about a huge, ugly tree in front of her window, so big and ugly even the birds wouldn't sit on him. ()

As a Changeling, Odo frequently took various form of birds, including a seagull, Tarkalean hawk, Tarkalean condor and a Arbazan vulture. ()

Moments before  was destroyed by a massive gravitational anomaly in 3190, the birds on the surface attempted to escape by flying upwards, all of them expiring in the upper atmosphere. ()

Birds in art
Birds were often seen incorporated into pieces of art, like sculptures. (, , )

A bird-like creature was seen on a Vulcan wall tapestry seen in a corridor of the monastery at P'Jem and on the planet Dekendi III. () The monastery at P'Jem also featured a bird on wheels sculpture in its atrium. ()

The Romulan logo consists of a bird-of-prey holding Romulus and Remus in its talons. ()

Da Vinci was so fascinated by Tuvok's Vulcan ears that he drew a picture of a caged bird with pointed Vulcan ears as wings. ()

Sentient ornithoid species

Bird species

Arcturian dog bird
Ba'ku hummingbird
Blackbird
Bluebird
Borogove (Earth; fictional)
Canary
Corvidae (Earth)
Crow
Raven
Dove
Eel-bird (Regulus V)
Finch (Earth)
Flitterbird
Fowl (Earth and Rakhar)
Arkarian horn fowl (Arkaria)
Chicken (Earth)
Wyandotte chicken (Earth)
Duck (Earth)
Dunghill bird (Potak III)
Goose (Earth)
Peacock (Earth)
Quail (Earth)
Luhvian quail
Swan (Earth)
Terellian pheasant
Great Egret (Earth)
Gunji jackdaw
Joranian ostrich
Loon
Parrot
Cockatoo
Macaw
Pigeon
Passenger pigeon
Raptor
Buzzard (Earth)
Eagle (Earth)
 (Earth)
Baneriam hawk
Pyrithian moon hawk
Reeta-hawk (Argratha)
Sorrowhawk (Alcor IV)
Tarkalean hawk (Tarkalea)
Norpin falcon
Owl
Cyclops owl (Alcor IV)
Great Horned Owl (Earth)
Tarkalean condor (Tarkalea)
Vulture (Earth)
Arbazan vulture
Rectilian vulture
Risian bird (Risa)
Seagull (Earth)
Sparrow (Earth and 892-IV)
Starling
Toucan
Unnamed ornithoids

See also

Big Bird
Bird-of-Prey
Blue Parrot Café
Bluejay 4
Clay pigeon

Eagle Valley, DEV
Great Bird
Great birds of the galaxy
Great bird of the galaxy
Lovebird
"Night Bird"
Night owl

Old Crow

Velociraptor
Warbird
Wentlian condor snake
Year of the Red Bird

Appendices

Background information 
In the first draft story outline of  (while the story had the working title "Danger Zone"), Balok's species was avian.

The final draft script of  referred to both the bluejay and the penguin, however both references were removed from the final edit of the episode. A deleted scene from  established a type of bird known as the Rigelian parrot. (ENT Season 3 DVD & Blu-ray special features)

In the revised final draft script of , a metaphorical bird was mentioned by Romulan officer Decius. He specifically imagined a Romulan Bird-of-Prey which he was serving on chasing after and defeating the Enterprise, likening that to a hunting bird causing a field creature to flee from it.

In the final draft script of , flocks of birds, rather than a single flock, were reported by Rodriguez and Kirk had two sightings of birds in flight instead of just one. The script also noted that the production crew were unlikely to capture footage of birds going into flight in the same area as they filmed the part of the scene performed by Kirk actor William Shatner.

External link

de:Vogel
 
Deleted and unused material in background