Do animals of the same CR summoned by conjure animals have to be the same animal?

I had a ranger player of mine ask. I know that the DM chooses which animals are summoned, and that the creatures are limited by the CR and number listed. But do they have to be the same creature?

For example, could he use the "Eight beasts of challenge rating 1/4 or lower" option and summon 4 wolves, a hawk, and 3 elk? Or would it summon 8 wolves?

There is nothing that says they have to be the same creature

The only thing the spell says about what creatures are summoned is:

You summon fey spirits that take the form of beasts and appear in unoccupied spaces that you can see within range. Choose one of the following options for what appears:

• One beast of challenge rating 2 or lower


• Two beasts of challenge rating 1 or lower


• Four beasts of challenge rating 1/2 or lower


• Eight beasts of challenge rating 1/4 or lower

Nowhere does it say the creatures have to be the same or put any other restrictions on the identities of the summoned creatures. Thus, they can be different. If there was a restriction, the spell would say it.

It is worth noting that it is the DM who decides what creatures are summoned.