Anolis cristatellus on Necker Island, British Virgin Islands, which is owned by Richard Branson. Photo by Charlie Smith.
That’s right, that Richard Branson, the Virgin Group magnate. Check it out here.
Back to Abaco
Well, the 2012 Abaco Expedition is over. For almost a year, we’ve been wondering what effect Hurricane Irene had on our lizard populations. Now we know.
A little background: initially, we feared the worst. Hurricanes had destroyed several previous experiments. The culprit was not the high winds, but the high water, which put our tiny, lowlying islands underwater for up to six hours, drowning or sweeping away all lizardkind. But then word trickled in that this time, maybe things weren’t so bad. The storm had come at the best time possible–absolute low tide–and from a direction that minimized the amount of storm surge that could build up in the protected areas where most of our islands occurred. Maybe things weren’t so bad.
So, back we came to Abaco several weeks ago to find out. We have two experiments going on. The primary study focuses on the effect of anole-eating curly-tailed lizards. What effects do the curlies have on the population size and behavior of the brown anole, A. sagrei? And, in turn, how do these changes trickle down to lower levels of the food web? These studies occur on islands up to 300 square meters in area (that’s less than 1/2 the area enclosed by the bases in a baseball infield).
Seaweed in a bush, showing the high water mark of Hurricane Irene
The result of the hurricane: mixed. Several islands lie in a very exposed position, and their populations were decimated, to less than 10 individuals on both. In case there’s any doubt about the culprit for this crash, the dried seaweed strung high in the bushes is clear evidence of the highwater mark of the storm. On most other islands, those not so exposed to the storm’s onslaught, A. sagrei populations are higher, even those with the curly-tailed lizards. It seems that it was a overall a good year for lizards, except for those islands exposed to the hurricane’s wrath.
Our founder effect experiment occurred on seven tiny–and very low-lying–islands. These islands were wiped lizard-free by the last hurricanes to pass through the region, Frances and Jeanne in 2004. We re-inoculated the islands with brown anoles in 2005, placing one male and one female on each island. As I reported previously, the genetic and phenotypic mark of these founder events were still evident four years later.
Given past history and the diminutive size of the islands, we were not optimistic. But here, too, the results were mixed. Three islands were almost exterminated: down to two adults (and, encouragingly, one recent hatchling) on one island, and 4-5 on two others. But as with the bigger islands, the results here, too, were mixed, as one population increased from 25 to 49 and several others held steady with large populations.
These results lead to an interesting situation. All populations were established by a founding event, but now only several of them have experienced a subsequent population bottleneck. How will that effect patterns of divergence among the island populations? And let’s not forget that those who have postulated the importance of founder effects for species divergence and even speciation suggested that it was serial founder events/bottlenecks that were particularly likely to lead to important changes. Who knows? Maybe next year we’ll return to find a couple of newly evolved species.
Fast moving grass-bush anoles were good noosing practice.
Ten days into my first field work experience, and I’m loving it. I am in Puerto Rico with Travis Ingram, and we are studying the interactions between Anolis gundlachi and Anolis cristatellus, which requires us to catch lots of anoles. I had never noosed anoles before, but I figured I could get the hang of it pretty quickly. Little did I know the challenges and adventures that were in store…
Photo by Scott Hartley.
Details at Chipojolab.
I’ve recently arrived at El Verde Field Station in Puerto Rico for my first real field season working with anoles. My main goal is to carry out enclosure experiments looking at the different components (resource competition and predation) of the interactions between anole species. I’ll post more about the research later, but for now I want to give a rundown of the enclosures I’ll be using.
Have you heard about the extremely expensive (and delicious) coffee from Indonesia made from beans that have passed through the digestive system of civets (hence called “cat poo” coffee because civets are sometimes called civet cats? Did you know that a similar coffee is produced in Central America, made from beans pooped out by Norops anoles? Well, that’s not what this post is about.
Rather, it’s about several recent studies on anoles in coffee plantations. One recent study, discussed at further length by Rich Glor, compares the biodiversity of sun and shade coffee plantations in Puerto Rico. The authors note at the outset that biodiversity tends to be higher in shade coffee areas, and wanted to see whether that was true in Puerto Rico. In a truly herculean effort, they censused the lizards, birds, insects and vegetation in six plantations, three shade, three sunny. This was a lot of work. Just for the lizards, they individually marked (via paint spray gun) nearly 5000 anoles.
It’s immediately clear to anyone visiting the Greater Antilles that humans have had a dramatic impact on natural environments. Even in those areas that remain forested and seemingly pristine, it isn’t difficult to find the stray coffee bush or mango tree. Indeed, some understory crops, such as coffee and cacao, have traditionally been grown under an intact canopy. These traditional practices have been changing over the past few decades, however, as large commercial operations have favored the efficiency of clear-cutting and subsequent cultivation in open sun. The impacts of this shift from shade to sun cultivation on biodiversity have been debated for decades, with most studies indicating overall losses in biodiversity and super-abundance of a few common species in sun plantations.
In spite of the prevalence of agriculture in the Greater Antilles, relatively few studies have investigated the abundance of anoles and other lizards in different types of agriculturally disturbed habits (but see my first first authored paper!). A new study by Borkhataria et al. (2012) conducts a comparative analysis of species abundance of birds, anoles, and invertebrates in shade versus sun coffee on Puerto Rico. This study is a welcome addition to the literature because the portion of coffee on Puerto Rico grown in sun plantations has doubled in recent years, although overall coffee production has declined.
This one can be purchased from Zazzle, and if you go to the bottom of the page, you’ll see a variety of other fridge magnets. Who knew there was such variety?
Into every life, a little rain must fall…but sometimes not enough. Our Bahamian brown anoles are delicate little flowers. Too cold and rainy, and they don’t come out. But too hot and dry, they also hunker down. Too windy–nap time. Like the three bears (or was it the little blonde girl?), it has to be just right.
And that put us in a bind. As our trip to the Bahamas wound down, we were running out of time, and as we got to our boat launch site, the weather didn’t look good.
Storm a-comin'
Waiting for the storm? Or Godot?
All we could do is wait for the storm to arrive. No point going out–it was too cold for the lizards to be active. And finally, the storm arrived, and we took cover in the only shelter available.
The relatively sparse anole holdings of the Cornell University Museum of Vertebrates.
I recently asked which museums have the largest holdings of anoles. I’ll now ask the obvious next question: which species are most represented in these museum holdings? Shouldn’t be much of a surprise: the first five species I checked were, indeed, the top five. But I’ll give one hint: the top five in Al Schwartz’s collection at the University of Kansas are not the top five overall.
So, who can name the top five, and in the correct order? And a bonus question: which species is number six?