"This subject of joining colonies together is very near and dear to us here at Lucky Glider Rescue & Sanctuary. This is true because we are constantly on the look-out to pair-up singles, re-united broken colonies, and helping to facilitate introductions for adoptive families and others.
OK so I will start with the bad news. The bad news is if you do not know what you are doing, a joining of singled individuals and a joining of colonies can result in death or maiming of one or more animals.
We have peculiar experience in this area since the LGRS rescue is now at over 70 animals. The bottom line is it is very dicey and sometimes outright dangerous to combine individuals from separate colonies. These animals are very territorial and the alpha individual from each side will proclaim it as his or her duty to kill outsiders. Now before anyone says that's not true because they were able to combine gliders together - of course we know it is possible. Successful introductions are possible. We've facilitated dozens. But unless you are prepared it can go bad very quickly.
A few points:
1. Introductions are easier if the animals in question are under 6 months. Sexual maturity seems to be coincident with territorialism.
2. The dynamic between two lone gliders that are being introduced is different than the dynamic between one lone glider and a colony or two colonies. Although we do have singles here who fight with every glider they are introduced to, generally speaking loners are easier to unite together than other situations.
3. A colony is two or more. When there is a cage mate or to protect, the alpha is much more likely to feel a need to defend.
4. It is not a good idea to mix weight classes. If you put a tiny glider in with a bunch of bigger ones, the little one can easily be killed within seconds - especially if it has no meat on its bones.
5. When you introduce gliders do NOT do it by putting the strange gliders together in a cage. You may not be able to separate them easily if they go to fight.
6. When you introduce gliders do it in a glider safe room - optimally a room like a bathroom with few hiding places - a room where you can easily lay your hands on them if they fight.
7. When you are trying to introduce just two gliders, hold one in one hand and the other in the other hand and calm them first. Slowly move them closer to one another and if they sniff each other and make nice, try to cradle them in your hands. If they don't fight, you can place them down on the counter or other surface and see how they do on their own. You can try a similar process if there are a pair you are introducing an outsider to, but it is a little trickier.
8. When introducing colonies together, which I don't generally recommend, you can put them all in the same room that you have maneuvering room in and stay very close to them. You may need a second person in case they pair off and fight separately.
9. Wear gloves. If they fight you need to IMMEDIATELY pull them apart. When you pull them apart they will blindly bite you and deeply. So if you don;t wear gloves and are afraid of being bitten, that will be a detriment to the gliders because it is not likely that they will break up on their own but rather continue to fight and therefore hurt or kill each other.
10. Don't introduce them while food is out. They have a tendency to fight more when food is about.
11. Do NOT leave them alone if it looks like the initial introduction is OK. Just because they seem to be getting along in the first few minutes does not mean it is a match. Do NOT leave them alone in a room or leave them alone in a cage and walk away. You must stand vigil. If they are getting along and it is time for you to go to bed, put their cage next to your bed so if they start fighting you can wake up and pull them apart.
12 Do NOT go out and get a new glider to add to a cage of existing gliders thinking it will all be OK. You must have a second cage in case it does not work out. You must deal with the idea of it not working out ahead of time. If you do not have the stomach for having two cages of animals, then don't try it.
13. If you can get help from a rescue or other entity that does this kind of stuff all the time, that is a good idea.
14. Do not go and buy a cute little joey and plop him in a cage with sub-adults or adults. He may be "gone" or half-eaten in the morning. Sorry so gross but people in this town have done this and they cried for days.
Lastly, yes there is the idea of doing a "slow motion" introduction where you incrementally and over a month or so swap bedding, swap cages, move cages closer together, etc. And yes, that can work, but in the end it either works or it does not work.
You need to decide if you want to try to find out right away if an introduction is possible or if you want to do it over a longer period of time. That is up to you. At LGRS, because we have so many gliders, we don't wait a month. We just keep trying different introductions. And that works for us in most cases. We have the "luxury" of doing that where a person who is just trying to introduce a strange glider into a colony will not have that choice. So of course the slow motion method is a good thing to try. But don't set yourself up for disappointment. And be prepared to have separate cages if it fails.
We have found that many gliders will "fall in love" with each other immediately and do not require a slow introduction. So long as you are able to separate them quickly if they fight, you can save yourself a lot of time and wasted build-up. You must pull them apart immediately if they go to fight. Immediately. Gliders can hurt each other very easily if left to fight. "
-Luckyglider
See Also
LGRS Introduction Primer
Colony Introductions