two adopted guinea pigs

Question
Hi There,

I hope you don't mind a very long explanation. I just want to give you all the background I can. I'd really appreciate whatever help you can offer me.

Last night after much thought and preparation, my girlfriend and I adopted two 1 year, 3 month old healthy female guinea pigs. They were both owned by a previous owner who surrendered them to our local humane society after someone in the home developed allergies to the animals. They kept them in separate cages but allowed them to play together regularly. Apparently they have always gotten along fine.

When they came to the humane society, the staff there gradually placed them together more and more until they had them living in the same cage for a couple of weeks (they arrived at the humane society towards the end of March). When we met them they seemed to get along perfectly and we were surprised to hear that they had been separate until recently. They made lots of happy guinea pig noises and if I recall correctly, even spent time together in the same hidey hole.

We've got them here in a 40" x 20" x 18" cage. It is a different cage than they were in at the humane society but the same dimensions and general idea. They have aspen bedding, lots of hay, a water bottle and some Martin's guinea pig food , a couple of toilet paper tubes, one plastic hidey hole, one empty coke 12 pack with the bottom cut out for another hiding place. The idea is that they'll be out of the cage whenever we're home and they want to be out. We work different hours so someone is home most of the time. This is how we've treated our 2 rats and we've got a way to have them all out (rats and cavies) and totally away from eachother at the same time. We're also piggy proofing all the exposed electricals and don't mind the inevitable destruction of our furniture, etc.

Since the cavies have been here (we got them at 6:30 last night) they have been quite intimidating to eachother. I understand they are maybe trying to establish dominance in a new place but I am a bit concerned. They slowly walk circles around the hidey hole the other is in and may a low purring noise that is obviously not affection. There has been a bit of swaying side to side as well which I hear is not good. They have had two or three very brief moments of physical aggression (no biting or anyone seeming to get hurt or squealing). Basically all of their encounters with each other since arriving here have been a bit hostile. By the water, food, hay and hiding spots (pretty much everywhere) they both seem uncomfortable with the others presence. Things have calmed don a bit since last night and nothing has been extreme or terribly alarming, just a bit out of line with the animals we saw at the shelter. They've mostly eaten and slept since they got here but they don't seem very happy around eachother. I'd say there have been more than a dozen little instances of dominance and posturing.

We have spent a bunch of time by the cage talking to them and occasionally have put our hands in the cage to offer treats (so far cucumber and baby carrots), pats, or a hand to sniff but we have not taken them out yet so as not to barrage them too much. We were thinking we'd have them out tonight for the first time.

Any suggestions on how to keep them happy together? Do you think this will continue or subside? Basically the question is how do I make my guinea pigs love each other so that we can get on to the business of all having a fun time together?   

Once again, sorry for the novel I've written here and thank you in advance for your help.

Regards.

Answer
To me, it sounds like you are doing everything right.  You have separate hiding places that they can go to, so they definitely have a way of getting away from each other.  A move can always be stressful on any animal, but you are doing everything right.  It was smart not to take them out for a little while, to get them acquainted with their new surroundings.  It doesn't sound like the aggression is very serious, and you may be right about them trying to establish dominance in a new place.  If they have been together for a little while, I wouldn't expect them to start being aggressive towards each other now.

The thing that is confusing is that you said they make a low rumbling noise, walking slowly in circles, and then swaying back and forth.  The low rumbling noise is often a sign of dominance in a group, so your theory about establishing dominance can definitely be correct.  But males usually make the low rumbling noise, circle slowly, and sway their little piggy butts back and forth during mating courtship.  So my question is, are you POSITIVE that you have two females? I'm assuming that since they have been in the humane society, their sex was accurately determined, so hopefully that is not an issue.  

I honestly wouldn't worry about it too much.  Females are not usually very aggressive towards each other, and they obviously need to establish dominance, especially in a new cage, with all new surroundings.  I would give them some more time to adjust and you should start to see them calm down.  

Good luck with them, and have fun.  Guinea pigs are really good pets.