This is a paid asset, but now you can download BIRDS PACK for FREE, but please remember this package is provided only for learning purposes or to be able to test before buying the product, NOT FOR COMMERCIAL PURPOSES.
Detail this asset from Unity Store: Original Link
BIRDS PACK v2.1 (Latest version)
***Included inside Animals Full Pack***
This pack contains 7 birds ready to populate and enhance any of your projects. Crow, duck, golden eagle, great horned owl, pigeon, seagull and sparrow.
The pack offers support for both PBR and Legacy shaders as well as in place and root motion animations. All rigs are set to mecanim generic.
Materials can easily be upgraded from Standard Built-In materials to URP or HDRP using the upgrader tool of the selected pipeline.