NOVA: How do you go about determining the sex of a crocodile, or
shouldn't we ask?
Leslie: Oh, you can ask! As you probably know, crocodiles don't have any
external genitalia, so you can't just look at them and say that's a
male, that's a female. With the younger ones it's quite easy. The males actually have a
distinct penis, so you can just pop them under a decent light with a
pair of tweezers and have a look inside the cloaca, the anal and
reproductive opening. With the older ones, you just turn them on their
back, put your hand in their cloaca, and decide if you feel something or
NOVA: What do crocodiles smell like?
Leslie: In the beginning I thought, "Oh boy, it's really going to
smell." But it's amazing how clean an animal a croc is. I'm not being
biased, and I'm not immune to their smell either. It's just that you
don't get that fishy smell you'd expect, even when you scoop a chunk of
fish out of their stomach. I've often had my hand right at the
esophagus, because they have a waterproof flap in the back of their
mouth that you have to hold down when you put the stomach scoop in. And
they don't stink. They don't even have bad breath.
NOVA: So you've had your arm down the throat of a live crocodile.
Leslie: Right. We give them a muscle relaxant, so even though they know
exactly what's going on, they can't do anything with their muscles. They
can't bite you. Nevertheless, before working on them we always put a
strong metal loop inside their mouths just to prop them open. Crocs have
an incredibly dense and heavy skeleton, and if you rely on somebody to
hold up their top jaw and they accidentally let go, it will crush your
NOVA: So this sort of work doesn't really bother the croc, even though
it's aware of what's going on?
Leslie: I wouldn't say it doesn't bother it. Any work of this sort is
invasive to a certain extent. But we try hard to minimize the
discomfort. We're quiet when we work, and we cover its eyes and ears
with a heavy towel to limit the stress. We caught one
particular male six times in a matter of two and a half months. So
either they don't remember or they didn't find it that bad or they get
hooked on the drug.