Category Archives: How to

How to: Sex a Baboon

Our observers can almost immediately identify any of our several hundred baboons by sight. I knew in a few weeks I could only be hope to be able to identify a select few baboons by sight. In pursuit of this itty bitty goal, the first thing I learned to do in the field was sex a baboon. It is a lot easier to tell who someone is with a baseline after all.

It’s also super easy.

And requires looking at a lot of baboon behinds.

The baboon butt has ~three main parts. The ischial callosity (their sitting butt pads), the paracallosal skin (PCS), and the sex skin. For baboon boys, the only one that matters is the ischial callosity. There’s just one continuous butt pad, and it’s kind of heart shaped (in little ones, at least).


Lady baboons are more complicated, because the PCS (the grey part surrounding the callosity in the male above) and the sex skin (not a thing in males?) help you determine whether the lady is with child or is optimally ready to be with child. For example, this lady’s sex skin says she’s ready to go.


Because of the sex skin, there are two distinct callosities on lady baboons. So, to figure out if you’re looking at a male or female baboon, check if there’s a split in the callosity. Here’s a bunch of baboon patoots to practice on.