Monday, December 22, 2014

Sexed, the un-sexed and the mis-sexed

When new cubs are born, one of our first tasks is to “sex” it (which is to say—distinguish if it is male or female). It seems quite obvious—look at the genitals! But it is never quite that easy with hyenas…

Because one of these hyenas is girl.
Yes it is true! Females have male looking genitals or a pseudopenis. However, a female’s pseudopenis is more round at the tip as well as lacks constriction toward the tip. We use this queue as our main objective to “sex” newly born cubs. Often, hyenas are mis-sexed as the former description can be somewhat “subjective”.  

FUZZ was one such hyena. Originally, former RAs had sexed cub FUZZ as a male. Only years later did we see FUZZ have nursing nipples and a torn phallus (evidence of birth). Sadly, FUZZ’s first cubs did not survive which is often the case for first time mothers. But cheer up because FUZZ has had cubs again!

In order to mitigate mis-sexing, we sex each hyena from birth 3 separate times. If we sex a hyena the same 3 times in a row we will designate it that sex. With hope, good binoculars, and some scrutiny we will sex FUZZ’s cubs correctly.


Jaime Tanner said...

Falafel was my boyfriend for years before I realized she was actually my girlfriend. I was so convinced that when I darted her as a cub and took measurements on her testes I though "hmmm, I guess his testes haven't dropped yet"

Lily J-U said...

Haha Dave was right! We thought FUZZ had awfully small balls, but never saw her phallus so I wasn't convinced! That's awesome she's having babies! INK is a grandma!

Michigan State University | College of Natural Science