The Orangequit is a bird that starts with "O" and has 10 letters.
If this is for a crossword puzzle a rare bird that starts with the letter o could be oner meaning a rare bird like a person meaning loner. Hope this helps.
Orange Roughy is a fish that people eat. It begins with O.
Owl
The Oriole is a bird that begins with letters or. The Oriental White Stork also begins with the letters or.
Egret
Canary is a bird. Cassowary is a bird.
penguin pelican
Little AUK
Several DINOSAURS have 13 letter names that begin with M, includingMacrurosaurusMajungasaurusMajungatholusMicroceratopsMongolosaurusMonkonosaurusOne BIRD has a 13 letter name, the Mistletoebird of Australia (Dicaeum hirundinaceum).
shrike
canary
Illinois
Hecate
pelican
redwing