Scientist at Work Blog: Life of a Lizard Wrangler

Jonathan Losos, professor and curator of herpetology at Harvard?s Museum of Comparative Zoology, writes from Colombia, where he is studying the biodiversity of anole lizards, an evolutionarily successful group that has produced 400 species throughout Central and South America and the Caribbean islands. For more on anoles, see anoleannals.org.

Feb. 18, 2013

I couldn?t miss it: a bright green lizard sunbathing on a brown branch that was sticking out from the middle of a large, round bush. What a way to start our lizard hunting expedition. It?s always a good sign when you find your first lizard within the first few minutes. Except when it isn?t. Find a lizard in five minutes, and you think you?ll be spotting them left and right all day long. And maybe, by the evening, you?ll be awash in them. But sometimes it doesn?t work that way; 10 minutes go by without another lizard, and then 20, and then an hour, and then two, and you realize that the first one was just a fluke.

That?s the kind of day it was. It didn?t help that the temperature barely topped 60 degrees Fahrenheit with a strong breeze, chilly even for lizards adapted to living at 9,000 feet. And to make matters worse, the little saurians are emerald green, closely matching the thick, bushy vegetation in which they live. This makes searching for them like looking for the proverbial needle in a haystack ? if the needle could swivel around to the far side of the straw when it sees you coming.

Fortunately, we were joined by a Colombian doctoral student, Rafael Moreno, who probably knows more about the variable-scaled anole than anyone else on the planet. Rafael didn?t arrive until late in the morning, but he still managed to spot two lizards, matching the daylong success of our team of three.

Four lizards isn?t a lot, but it?s a start. The first thing we do is whip out the video camera, sit back and record their behavior for half an hour or more. This way we can observe how they live their lives. Sometimes, though, it?s clear that they?re too preoccupied watching the watchers to behave normally ? pretty obvious when they?re hiding behind a branch, with one eye peeking out. If all goes well, the lizards will go about their business.

After that we pluck the lizard off its perch and take its temperature, just as you would a baby?s. We measure the dimensions of its habitat. How high was it off the ground? How wide was its perch? Was it in sun or shade? And did it hang out in the open or was it hidden among the vegetation? When you?re dealing with small evolutionary differences, the little details are what really matter.

Then we take the lizard for a ride back to the field lab (hotel room). We carefully pump its stomach full of water, inducing it to regurgitate. It?s the most effective and least harmful way to get at their diet. The soggy remnants from today?s lizards are pretty standard: flies, beetles, caterpillars and the occasional wasp. But actually, ?pretty standard? is a little surprising. The variable-scaled anole has a very large head, suggesting a powerful bite. That usually means a diet dominated by hard-bodied insects like beetles. Our data so far fail to confirm this prediction.

The goal of all of this data collection is to understand the natural history of this species. We want to understand how it is adapted to live in its environment. How does it cope with its predators and competitors? How does it deal with the high-altitude cold weather that is unusual for species in this tropical lizard genus? And more specifically for our project, how similar it is to species that live elsewhere? Has it evolved in similar ways to species that live in similar environments? Or has it found its own way of adapting?

Four lizards aren?t enough to say, but we?ll be back tomorrow, with a sharper eye for where to find them, and hoping for warmer weather.

Source: http://scientistatwork.blogs.nytimes.com/2013/03/14/life-of-a-lizard-wrangler/?partner=rss&emc=rss

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