Gerbil Family Habits and Hamster questions

Question
I went to an environmental center today where they had all sorts of animals, included among them 4 gerbils.  Well, they had 4 gerbils, along with at least 9 newborn babies.  I have a couple of questions about this, as no one there really seemed to be an expert.

First off, there were 4 adult gerbils in the cage.  Will they work as a team to take care of the babies or will the non-parents cause trouble?  They're in what is frankly a massive tank, at least 40 gallons if not more.

Second, I noticed that there were two nests, each in a corner.  There were 6 babies I could see in one and 3 in the other.  I wasn't poking and prodding because these were probably only a few days old, judging by their coloration and my experience with hamsters and their offspring.  Is it possible that what I'm assuming is/are the male(s) in there got the female(s) pregnant at the same time and they gave birth around the same time as well?  These aren't my pets, but I found their behavior really interesting after seeing my girlfriend's two hamsters raise litters.

Finally, my girlfriend, whose purchase of 3 Syrian hamsters this summer (that she was assured were all girls, turned out one was a boy)  has led to 17 babies, 9 of which are full-grown and in her house.  A week or so ago, one of her boys managed to escape his tank by lifting the lid off his cage.  Then, according to my girlfriend, he "Spidermanned" his way up in-between a couple of other tanks and landed in the uncovered tank of a girl.  She caught them in the act when she came home.  There's no obvious way to tell if she's pregnant yet, is there?  My girlfriend says that the girl hamster still smells like she's in heat every few days, but so did her mother when she was pregnant.  Also, the two potential parents have different mothers but the same father.  I was wondering if this might lead to complications or anything of that sort?  The mother to be is around 5 months old and the father to be is around 8 months.  Finally, do you have any tips on giving away any potential offspring?  There is simply no room left in my girlfriend's house for any more hamsters.  She has 11 10 gallon tanks and 1 20 gallon and no floor space left.  She loves animals but there just isn't any space left.  If there isn't a definite place for them to go in advance I'm afraid she's going to end up keeping even more hamsters.

Thanks!

Answer
Hi Robert

Regarding the gerbils - a lot of people remove adult females from a tank when one is pregnant in case they attack the litter from the other gerbil.  However, it could be that they discovered the litters and don't know who they belong to. If they remove one female then they might remove the wrong one and then find that the litter dies.  The fact that they are in a huge tank and the litters appear to be separate makes me feel that somewhere along the line a male was left in the tank with them and two gerbils got pregnant at the same time.  It is fine to leave the male in with them - I have seen some males raise litters really well.  However, the danger is that they mate the day a litter is born and as the female is really fertile then another litter could appear in a few weeks time if the male is still in with them.

On the subject of your girlfriend's hamsters.  Hamsters do come into season every 4th day and if the male happened to be out on that day then the hamster could be pregnant.  The fact that your girlfriend found them mating makes me feel that perhaps they did successfully mate - on the other 3 days the female can be really aggressive towards a male and only really becomes submissive when she is ready to mate.

It is probably a case of waiting 16-18 days to see what happens.  If you find she is pregnant (you only really notice the signs a day or two before the litter is born) and your girlfrend can't cope with more hamsters, then I would be tempted to get in touch immediately with a pet shop or rescue and see if they will help.  If they are happy to help you re-home them, then once the babies reach 2 weeks of age (I never handle them before this age) then if you start handling them a lot so that they become tame they will make much better pets.  At 4 weeks they need sexing and the boys separated out.  At this time you could hand over the litter to the pet shop or pet rescue.  At 6 weeks they will all need a cage of their own otherwise they will start fighting.  

In an ideal world you shouldn't mate brother and sister as sometimes there can be problems with the litter.  I had a litter once whose parents were brother and sister and the babies had one red and one black eye - apart from this they seemed fine.

Even if your hamsters did mate there is no guarantee she will produce a litter.  She might miscarry/reabsorb the litter so you might be in the clear.  

I hope this helps.

Regards
Sheila