We have two chinchillas of named Chewy (age 4.5)and Giz (age 5.5).
Giz was our first, and we got Chewy about 6 months ago to give him a friend since he seemed pretty lonely. They hit it off pretty well when we introduced them during a playtime - typical dominance mounting and a bit of chasing, but that stopped really quickly.
About 4 months ago we moved them into the same cage and there seemed to be no dominance issues - The occasional mount as Chewy made sure Giz remembered that he was dominant, but nothing out of the ordinary.
They lived together in the same cage for three months (even a whole week on their own when we were out of town) with absolutely zero issues. Then, one day, we woke up to a ton of Giz fur in the cage and him missing a good portion of fur from his backside. We separated them immediately.
What's odd, and what I feel sets this apart from the thousands of other my-chins-fight-now posts, is they way they behave during shared playtimes and how they've interacted the few times we've tried to re-cage them. When put together, they are absolutely loving to each other and completely best buddies; grooming, playing, cuddling, and even taking turns on the dust as completely civilized chins.
After a bit, Giz starts wagging his tail and making high-pitched chirps - both of which seem to be part of the chinchilla mating ritual, to my knowledge. Chewy immediately responds by chasing Giz down and mounting him. Giz will then continue to wag and chirp while running away, and chewy gives chase. Giz will occasionally try and mount back, resulting in a chinchilla tornado, but that's pretty rare.
From my observations, it would seem that Giz is looking for a mate, and Chewy responds with re-asserting his dominance to ensure that, if there IS a female around, he gets first dibs.
When they are separated they are really sad. They call out to each other constantly and make lonely sounds. I've found them staring at each other too. It's depressing for all parties here for them to be apart. Even when they are in different rooms they still call out.
I don't want them to hurt each other and I know that being careless could result in terrible consequences like death.
So, I have a few questions for the experts here.
Why, out of the blue, has Giz started with this wag-and-chip? Could this be due to seasonal change or something?
What do I do!?