turtle behavior

Question
I have 2 turtles, I don't know their sex. The slightly bigger turtle keeps scratching and biting on the others back. I want to know what this behavior is. I'm worried that "Shannon" is hurting, or picking on "Gene". Should they be separated?  Thank you in advance.

Answer
Hi Tina,

I need more information in order to help you.  What species are the turtles, and how big?  What is their setup like--tank size, type of filter, basking/UVB lights, diet, temperatures, etc.?  How long have you had them, and is this new behavior?

Turtles can't be sexed until they're mature, so while there might be some breeding behavior going on, if they're still fairly small it's probably not that.  The other likely issue is that they're overcrowded, causing the larger, more aggressive turtle to bully the smaller one.  Turtles require a lot of room, much more than what the average keeper allows (and far more than what the typical pet store recommends, which seems to always be a 20 gallon tank).  Unless your turtles are hatchlings, the usual 20-30 gallon tank isn't big enough.  I'm guessing that your turtles are red-eared sliders, and at maturity if still housed together they will need *at least* a 150 gallon tank.  If you try to put turtles together in tanks that are too small, aggressiveness is a common result, and that may be what's going on.  Water quality is another issue with too small tanks.

If you have them in a large tank and the behavior is still happening, then I would separate them.  It can be very stressful for a turtle to be bullied--it often causes them to eat less, bask less, etc., which can lead to illness.  If by chance it's breeding behavior, I would also recommend separating them because constant harassment by the male can also cause stress (and there are too many RES as it is, so it's very difficult to find good homes for them).

If you can post back with more information, I can help you figure out what could be causing the problem.  Thanks!