A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- Uca sp.
- Uncia uncia
- Upupa epops
- Uratelornis chimaera
- Uria aalge
- Urocissa erythrorhyncha
- Urocitellus columbianus
- Urocitellus richardsonii
- Urocolius macrourus
- Uromastyx acanthinura
- Uromastyx aegyptia
- Uromastyx dispar
- Uromastyx geyri
- Uromastyx ornata
- Uromastyx thomasi
- Ursus americanus
- Ursus arctos
- Ursus maritimus
- Ursus thibetanus
- Urticina felina
- Urticina piscivora