When to sex robo babies

Question
Hi Tammy,
I bought two robo hamsters last December - actually the petshop guy told me they are two different species that can live peacefully together and won't reproduce, however it turned out that the male is a normal (sand gray) robo and the female is a white-coloured one. Anyway on Feb 6 the female gave birth to 4 babies which was a surprise, and I separated the male from the female the next day because she was attacking him. Now the babies are 4 weeks old and I think I'll have to separate them to prevent inbreeding (and having more litters - the mother gave birth to another litter yesterday! Apparently the male impregnated her before being separated).

I followed the instruction and looked at their underside but it was not easy, they look all the same, plus robo babies wiggled and twisted and did not like being grabbed and watched. I wonder if 4 week old pups are still not ready to be sexed? I can see the anus all right, but it is very difficult to find the other vent - all I see is the anus and what looks like a belly button (tiny protrusion). Is the urogenital vent less prominent than the anus? And when will they start mating? I don't think I can afford more hamster babies. Also I'm afraid if grabbing and inspecting young hamsters might stress them too much. How often and to what extent can I handle the young robos?

Thanks,
Hugh

Answer
Hi Hugh,

This is a vey common problem when buying from Petshops - they neve know what hamsters they actually have and they give out horrendous information too!  Hamsters from different species should never be housed together!  Petshops neve know how to sex their animals properly either - it is always best to purchase from responsible breeders instead of petshops.

Please do not allow the male and female to be together again - they are probably brother and sister so the babies could have any numbe of health conditions and also a shortened lifespan too.

On the day the female gives birth she is receptive to the male and able to get pregnant again for a few short hours - which is why the male will try to be as heplful as possible to her - helping to clean the babies, disposing of the after birth, bringing food to the mother etc.  just so he can stay as close as possible to her so he can get chance to mate with her!!

It is very, very difficult to sex baby Roborovskis - they all look the same until they reach 7 or 8 weeks old and some are still developing up until they reach maturity at 3 or 4 months old!  As you have found out, Roborovskis do not breed as young as other species too - so at least you have a few weeks to play with, until you need to sex them!  They definately need sexing by the time they are 8 weeks old, but i have often got it wrong at that time - and fingers crossed, have never had any accidents.

It is absolutely fine to hold the hamsters by the skin on the back of their necks - just make sure you have a firm grip!  It will not hurt them at all.  You can hold them for as long as you like, but the longe you hold them, the more squirmy they will get!

It is very difficult to sex Roborovskis who are under 4 months old because they are still so small and are still developing.  Both sexes have scent glands but the males is usually much more visible - this will be a yellowish stain where the belly button should be.

Females will have visible teats but they can be hard to see under the fur.  The two openings are very close together on the female and usually so close that they look like one opening.

On the male the two openings are much futher apart but the gap is usually bigger as they get older.  Also, if you hold him by the skin on the back of his neck, his testicles will drop and may be more visible - showing that he is a male.

If you are still having problems then you can apply gentle pressure on both sides of the openings with two fingers (one finger by each back leg - with the openings inbetween the two fingers)  On the male the penis should pop out - this can take some practive though so just be patient.

It might be slightly easier for you because you have the mother and father to compare the babies with.

Please let me know if you need any more help.

Kind Regards,

Tammy