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.
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.
Lizard Motion Detection Gizmo. Read all about it at http://chipojolab.blogspot.com/2012/05/motion-detection.html
We all know that anoles have a keen sense of vision. But how much does an insect have to move to draw a lizard’s attention? And do species vary in their sensory abilities? Dave Steinberg of Duke University is in Puerto Rico, trying to find out.
Nearly one week has passed since I entered the Bahamas in search of Anolis brunneus, the Crooked Island anole. Since then I have also been joined by Michele Johnson and two students to help study the behavior and ecology of this poorly known species. I am happy to report that the lizards are treating us well and copious amounts of data are being collected each day. There are several developments that I thought might be of interest to the readers of this blog.
First, the anoles are everywhere! We have surveyed the entirety of the island and have found lizards in almost every habitat: in the sea grapes, in the forest, along the beach, along the arid southern coast, and even in the Bahamian Pines. The only habitat seemingly void of these fine lizards are the mangroves and coastal sea grasses. Green and brown anoles on this island seem to readily share the habitat as we regularly see them in close proximity but rarely fighting for perch space. Compared to A. sagrei, A. brunneus is mild mannered and extremely easy to capture making it a real pleasure to work with.
Ceratophora tennenttii from The Lizard Lab website
We’ve had a continuing series of posts on anole wannabees (most recent here), those lizards other than Anolis that sport dewlaps. Many of the best faux anoles are Asian agamid lizards. Some of these lizards are anole-like in other ways. For example, the fascinating Sri Lankan Ceratophora, though lacking a dewlap, parallels some anoles (well, two in particular), by sporting an appendage on its nose. Read more about these fascinating lizards at Martin Whiting’s Lizard Lab website.
Anolis brunneus male
Today marked the beginning of my search for Anolis brunneus, the Crooked Island anole. As I discussed in my last post, this species has several unique qualities including its relatively elongate face and permanently pale disposition. I am happy to report that this rarely observed species has been located in all its drab glory. Over the next ten days I hope to collect data on this species’ distribution, ecology, and behavior. I will kick these reports off with a brief background about the island.
Crooked Island is one of the “Out Islands” of the Bahamas, located in the far southeast corner of the island chain. The island is a mix of salt marshes, sea grape, mangrove, and scrub trees rarely reaching more than a few meters high. Despite this seemingly serene picture, the island has a history of failed agricultural efforts, the largest being cotton plantations around the turn of the 19th century which covered ~10% of the total land area. At the peak of the cotton boom the island maintained approximately 1200 inhabitants, primarily slaves, but this has dwindled to only 300 today and continues to fall. The island now appears as an odd mix of both 19th and 20th century ruins that range from abandoned plantation homes to hurricane battered wood frames, many of which have been overtaken by the forests. Except for a few hotels that cater to bonefishermen, the island has virtually no tourism. Crooked island is home to several other lizard species including abundant A. sagrei and Leiocephalus, but more on this in a later post.
I am optimistic that we will come away from this field trip with substantial new data on this species. The one trick, we need to find them! Because of their pale color I have found them extremely difficult to find and track in the trees. Stay tuned!
A year ago, I posted on 20 years of research on anoles in the Bahamas, discussing our current projects: 1. the effects of brown anoles on the ecosystem, and how those effects are altered by the presence of the anole-eating curly-tailed lizard; 2. whether and how brown anoles will adapt to the presence of the terrestrial predators, which forces them to move up into the vegetation, where they must cavort on narrow diameter vegetation; and 3. the effects of an experimental founder effect in which we seeded each of seven islands with a pair of anoles and followed how the populations evolved for a number of years. The first two projects–as well as the methods we use–were discussed here, in one of my finest AA posts, if I do say so myself. The third project led to a paper on founder-effect evolution that appeared two months ago; you can get up to speed on that one here.
Every year we arduously return to the Bahamas to see how the population numbers have risen or fallen, to assess the state of the ecosystem, and to examine whether the morphology and genetics of the populations have changed. And so, we head south and east again. But the 800 pound gorilla in the boat concerns what happened last August. Hurricane Irene, which at its peak was a Category IV storm and which gained fame by wreaking havoc all the way to Vermont, scored a direct hit on our study site on Great Abaco Island (also on our newly established study in Staniel Cay, to the south).
We’ve got a history with hurricanes, and it’s not a happy one.
Bright green male who won the fightAn instantaneous color change for the loser.
Two adult male A. maynardi were sitting on a flat tile deck about 6 inches apart with dewlaps exposed and head crests up. There was much head bobbing and they showed their bright yellow dewlaps by turning their heads sideways. Then fast wrestling occurred – It looked like they were using their mouths to bite each other — with the participants separating briefly before repeating the wrestling, during which they turned each other over and over. We (humans) may have precipitated the end of this bout by opening a door to get a camera, but one male ran off the deck down the vertical wall and the other stayed to watch. At this point a small female ran between the two towards the male nearest the deck. After 10 minutes the male that moved off first is sitting on a hand rail and has changed to his dark color, while the other male remains on a step still bright green.
Also: a brief note on nocturnal feeding. We had our first decent rain of the season on the 24th April and on coming home at about 8.30 pm, a large cosmopolitan gecko and a male A. maynardi were sharing the same wall and feeding on insects attracted to the outdoor lights.
Comparison of panfish poles, click for larger image
In a comment a few months ago I promised a review of alternatives to the beloved but discontinued long-backordered, Cabela’s Telescopic Panfish pole. As of Monday, Cabela’s claims that the panfish poles we have grown to love will be available again on May 6th. With any luck they will be back to stay and the review that follows will be moot, but after being fooled by two previous restock dates that came and went, we set out to evaluate alternatives. Read on for a review of each.
Even with their large size, and one spending quite some time in their territories, it is somewhat difficult to find a Giant Anole during the day in the Dominican Republic. The most widespread and common species (at least in the Dominican side) is A. baleatus, which is not an unusual sighting at the mesic riparian forest of “Gran Cañada” in the botanical garden of Santo Domingo. But even there, observations are limited by spotting an animal right after it moves to hide away from view (squirreling or slowly sliding around tree trunks). The population in this particular locality seems to be stable and not pursued by people, whom locally have the misbelief that they are aggressive and harmful to humans.
Regarding a local species, A. barahonae, possibly the first encounter I had with this species was back in 2003, in the hills above Enriquillo, southwest of Barahona, where through binoculars, I saw at the distance and high in a large tree a White-necked Crow (Corvus leucognaphalus) holding a large, strong, greenish anoline lizard it its beak. Although I couldn’t see many details of the lizard, I think it must have been A. barahonae because it is the only Giant anole known from that locality. The White-necked Crow forages mainly in flocks and in the canopy, so I suppose that they represent a common predator to that anole species.
After that encounter, I have seen just a few more to date: one basking in a large tree in a shade coffee plantation, also in an epiphyte-packed tree in a cloud forest. This time (yesterday), a fellow local biologist and I were exploring some rivers in the Nizaito watershed, also south west of Barahona. Specificly at a tributary stream that pours into Río Paraiso, while taking photos to a basking Ameiva taeniura aside the road, about 11:00 a.m., I heard some noise coming from a nearby cluster of rather young Cecropia trees. Then my attention was caught by a glimpse of the wing beats of a sphinx moth, soon realizing that it already was in the mouth of a Baoruco Giant Anole. The anole kept still while holding its prey, with tail hanging outwards off the leaf where it was perched.
Unfortunately, I didn’t see the action before the attack happened, but as seen in the pictures, the dead leaf of the Cecropia was probably the perch that the moth used for roosting throughout the day. As most moths are nocturnal in habits, it is likely that it was inmobile siting there just relying in its cryptic coloration and pattern. In an earlier post: A. cuvieri On The Prowl, some excellent photographs by fellow naturalist Father Sanchez showed a Puerto Rican Giant Anole (Anolis cuvieri) deliberately moving about at moderate heights and using several kind of perches. I often imagine that all these anoles would take their prey mostly up in the canopy or high in the tree trunk, but these photographs of the A. barahonae eating this moth were taken at a height of 3 meters, atop of a small tree (Piperaceae) almost overlapping with a taller (8 m) Cecropia tree. Previous to when I heard the sounds coming from the attack, I didn’t notice any motion in the area as I was pretty close. The anole may have been stalking or more likely foraging and scanning this (unusual?) substrate in search of random prey.
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