Spanish animals are a bit weird. Below is the rules I've made up in my head to try to explain them. Can someone tell me if this lines up with what they've seen?
From what I understand there are 4 types:
In the first type, the word changes grammatical gender depending on the animal's actual gender. The animal is assumed to be male unless proven otherwise.
El perro (The male dog) -> La perra (The female dog)
El gato (The male cat) -> La gata (The female cat)
In the 2nd type, the word is grammatically male AT ALL TIMES, and the word "hembra" is added if the animal's actual gender is female. The animal is assumed to be male unless proven otherwise.
El delfín (The male dolphin) -> El delfín hembra (The female dolphin).
In the 3rd type, the word is grammatically female AT ALL TIMES, and the word "macho" is added if the animal's actual gender is male. The animal is assumed to be female unless proven otherwise.
La serpiente (The female snake) -> La serpiente macho (The male snake).
The 4th type is pointed out by Andrekune below
Does the above ** 4** rules make sense? And if they do, can you give more examples of animals and where they line up on this list?