by Jonathan Losos , 4/11/13 NyTimes Blog-Scientist at Work
Colonia Tovar, a small town in the mountains above Caracas, was founded by Germans from Baden in the 1850s. In recent years, it has become something of a tourist attraction.
For the last leg of our lizard expedition, we’ve moved to Colonia Tovar, a quaint German-flavored town in the mountains above Caracas. Mercifully cool, the weather at 7,000 feet is a relief from the brick oven that is Maracaibo. So far, the trip has been reasonably successful. We’ve discovered new aspects of two little-known anole lizard species. We’ve also identified similarities and differences between these species and the habitat specialists that evolved on Caribbean islands.
The last leg of the trip, however, promised to be the most challenging. Our primary quarry is the tiger anole, Anolis tigrinus. The tiger is another mystery. Living in the middle elevations, it is nearly identical in appearance to the small twig-using specialists in the Caribbean. But whether it actually uses narrow surfaces or behaves like a twig anole is unknown.
What is known is that twig anoles are extremely difficult to find. They are well camouflaged in various shades of gray and green. Most species are small, move very slowly and often live high in thick tree vegetation. We did have good success in Colombia finding the twig anole-like variable-scaled anole, but they occupy a different habitat in the bushy Andean matorral, or scrubland, where the lizards are lower to the ground and more readily discovered.
So if the twig anole is hard to find, and the tiger anole looks a lot like the twig anole — well, that tells you something about our prospects. As we set out to search for the tiger, we agree on a bet of unprecedented size — three candy bars — for the first person to find one. Candy bars are surprisingly expensive in Venezuela, but none of us were worried about the large ante. Rather, we all expected a fruitless day of lizardless searching, in recognition of the fact that none of us expected to find any.
Shortly after arriving at midday, we began our search in the little patch of woods behind our rooms at Cabañas Heidelberg. One side of the property is a grassy hill sloping down to a small stream; on the other side there is a forest. Anthony Herrel of the Museum of Natural History in Paris walked down to the stream to begin searching the woods. Rosario Castañeda, a Colombian biologist, and I used our binoculars to scan the treetops from higher ground. “I’ve got one,” Anthony shouted up the hillside.
Jonathan Losos A tiger anole on the prowl.
As with our search for the variable-scaled anole a week and a half ago in Colombia, we had struck gold quickly. But this time the story was different. Our early luck wasn’t dashed by a quickly following drought. Moments later I spotted another tiger anole perched on a vine hanging down from high in the canopy. Out came the two video cameras. Then a third lizard marched into view.
And that’s how it went all afternoon, one lizard after another. A veritable lizard cameo queue formed as we tried to keep track of the additional tiger anoles. There were as many as four at one point, most spotted by Anthony, waiting for their 30 minutes of fame.
From watching nature documentaries on television and reading stories about researchers like Jane Goodall, many people have a romantic view of what it’s like to study animal behavior in the field. The reality is that most animals — certainly most reptiles — spend most of their time doing nothing, remaining motionless. The thrill can evaporate quickly, replaced by boredom. And mainland anoles can really bring on this ennui. The variable-scaled and beach anoles are masters of inactivity. But perhaps this is evolution’s end game to avoid drawing the attention of the many predators found in mainland settings.
Imagine our delight, then, to discover the tiger anole to be an exception. They are a blur of activity: eating, scratching, pooping, posturing, courting and almost constantly on the move. And not only that, but the males were displaying frequently, pumping out their beautiful white and orange dewlaps to intimidate their rivals and impress the lady lizards. A hot afternoon at the lizard revue.
This activity, however, presented its own challenges to the lizard videographer. It’s like going from tortoises to jack rabbits. We tried to film from a discreet distance, but it was easy to lose track of them as they darted in and out of the vegetation. That lead to a frenetic — indeed, stressful — time trying not to miss valuable data if the lizard did something cool out of frame. Still, I’ll take stress over tedium any day, particularly when it means discovering interesting tidbits of what it’s like to be a tiger anole.
Jonathan Losos The writer, tracking anoles.
As expected, the lizards were primarily found on narrow surfaces — twigs, small branches, vines and lianas. Combined with their great anatomical similarity to their Caribbean counterparts, they seemed good candidates for membership in Club Twig Anole. But as the videotaping progressed, the tiger anoles presented us with one further surprise. Anoles that use narrow surfaces — whether Caribbean or mainland — tend to move slowly, often crawling at a snail’s pace, so we expected the same for this species.
Wrong again.
These guys could boogie, and they did so frequently and in a very untwiggish manner. These lizards may look like twig anoles and live in twig anole habitats, but they certainly don’t act like twig anoles. What does it mean? At this point, we don’t know, but our mental wheels are spinning just trying to come up with ideas.
The action continued fast and furious until late in the afternoon, when cool weather and impending dusk called an end to the day’s frolicking. We returned to the room, exhausted but exhilarated. We had expected not to find any lizards and instead had found more than a dozen. We had expected a sparse smattering of drying lizard paint, but had been given a reptilian Renoir, an intimate living composition in vibrant color. What a day — one of the best ever in my three decades of lizarding.
But as always, questions remain.
In our observations, we found four males for every female. That may reflect greater activity or choice of more conspicuous perches by the males, but how can we test this idea? We still have some lizard-catching tricks up our sleeves, but they’ll have to wait for another day. For now, it’s off to dinner and to purchase Belgian-born Anthony his three bars of well-deserved dark chocolate.
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