Some of you might have heard me complain about how behaviour is neglected by biologists of other stripes. But I recently realized that there is one aspect of lizard behaviour that every lizard biologist has more than an inkling of –a lizard’s escape behaviour when being pursued by someone trying to catch it!
Not surprisingly, different species of lizards have very different approaches to evading an oncoming human, and therefore need to be caught in different ways. However, it’s worth noting that there is a LOT of variation between individuals, the sexes, and populations of a species in their wariness.
The easiest way to catch a lizard is to “noose” it, by attaching a slipknot at the end of, ideally, a retractable fishing pole (but any stick should work), and sliding the slipknot over the head of the lizard of interest. Lizard biologists can spend lots of time debating the best ways to construct a noose, and freak out when our favourite fishing pole threatens to go out of stock. One obvious caveat of noosing lizards is that you also need to extricate the animal from the noose as soon as possible, which can be difficult with large, sharp-toothed, very unhappy lizards.
Here are some of the lizards I’ve managed to catch in the last few years:
Sitana: these lizards, being primarily terrestrial, can be very easy to catch. They allow you to get quite close, and can be caught with a standard lizard noose. If they spot you and decide to run, they may run long distances but will likely stop in the open, meaning that you can walk up behind them and try again. However, these lizards are incredibly well camouflaged, so keeping an eye on them when they run is essential. Even if they run into cracks in the ground or crevasses, they often emerge after a few minutes. They only become impossible to catch when they run into dense shrubs, where they apparently have no problem staying indefinitely. Working with Sitana has changed my idea of what a dense shrub is, however—my proudest lizarding moment so far has been catching a Sitana that had run about two feet inside a cactus.
Anolis: all anoles I’ve worked with have this most annoying habit of weaseling around the tree on which they are perched. As soon as you make your way to the other side of the tree, they’re back where they started, and you begin to feel like a dog chasing its own tail. As a team effort, however, catching anoles can be a lot easier! As with Sitana, males are much easier to catch than females—males seem far too preoccupied with displaying to pay attention to much else. Anoles can also be very easy to spot and catch at night–many sleep at the ends of leaves or twigs, positively shine under torchlight, and can be grabbed by hand.
Platysaurus: atypically, female flat lizards are far easier to catch than males. Females are adventurous, moving far from their shelters under rocks to forage, and can readily been noosed. The brightly coloured males, in contrast, hang around close to their shelters, and bolt for cover as soon as they are approached by a noose. Here’s one method that works for males, courtesy of herpetologist Graham Alexander—place some bread on ground as bait, place a piece of sticky paper between the male’s shelter spot and the bread crumbs, and wait until the lizard’s hunger overcomes his wariness. Sticky paper is far from ideal, as you have to wait patiently until a lizard gets stuck and then immediately free it by rubbing oil on the paper.
Skinks: when I asked a renowned herpetologist how best to catch a skink, his answer was “don’t.” I’ve once successfully noosed a skink, but the pain was really not worth it. Because skinks have no necks, the noose needs to be slid behind their forelegs before it can be pulled tight (and forget about noosing skinks without forelegs). Pitfall traps (i.e. a bucket in the ground) can work well, but obviously mean that you can’t catch particular individuals. I imagine sticky paper would also work for skinks but I don’t know what you would use as bait.
Gerrhosaurus: okay, so I haven’t actually caught a plated lizard. But I’ve spent a lot of time lying very still on my belly near a plated lizard burrow, waiting to pounce on the lizard when it emerged, unfortunately to no avail. But OTS South Africa 2009 course staff Graeme Ellis has used this method successfully, or so he claimed when he handed me this lizard.
I’ve saved the best for last. I haven’t worked with Draco myself, but I asked my colleague Sreekar Rachakonda, who has worked extensively with these phenomenal animals, for a quick description of how he catches them
Draco: these gliding lizards camouflage rather well against the trees on which they perch, usually high up. Catching them is a two-person, four-step procedure.
“First: Get some really long poles, 25 feet +
Second: Used them to disturb perched Dracos
Third: When Dracos are disturbed, they usually glide down
Fourth: After a couple of such attempts, they usually glide so low that you can easily capture them by hand”
Any other methods out there? Have any of you used nets, or perhaps catapults (I believe that’s a thing)? Other lizard taxa that are especially entertaining to catch?