Animals that do and don't count towards level requirements
Levels where certain number of animals are required are
Noah’s Ark 2 of each animal3′s Company 4-of-A-Kind, Make it Even
5 of a kind.
All feed animals are included in level up requirements and it is advisable to aim for at least 5 of these from when you collect your first of that kind of animal.
If you do not have one of a particular animal it is not necessary to get it to level up we just don't like them being lonely from the start.
If an animal is an ultra rare or can not be bought (this only applies when you only have one of a kind as animals that are breedable are often restricted to buying the breeding pair) it will not be required to level up.
However you will need to breed them up if you have two of a kind and the only way to get them is by breeding,
You do not need these animals to level up;
Any Ultra Rare animal bought with FaceBook Credits, Wild Life Points or cash