Category: Notes from the Field Page 5 of 22

Abaco I just got back from a trip to the Bahamas with Losos lab post-docs Anthony Geneva and Alexis Harrison, accompanied by expert lizard catchers Inbar Maayan and Sofia Prado-Irwin (Harvard graduate student). We parted ways for the first few days of the quick trip, with Anthony and Sofia headed to Bimini and Alexis, Inbar, and myself on Abaco. Read more about the Bimini trip in Sofia’s recent post.

Friends for the Environment Kenyon Center field station

On Abaco, we stayed at the brand new Friends of the Environment Kenyon Center. We were really impressed by the great accommodations of this field station. The station was sustainably built and had all the modern amenities we could wish for. The field lab was large and equipped with microscopes and plenty of counter space. We were equally impressed by the staff and their outreach efforts. The Friends for the Environment does a fantastic job providing nature education to local kids from age 3 through college! Their ambitious organization seeks to provide high-quality and low-cost facilities for visiting scientists and to provide outreach and education to the local community. We spoke with the coordinators of the organization who told us that any time researchers are looking for extra hands in the field they are happy to arrange local students to assist. We strongly encourage others traveling to Abaco to stay here!

“In the end we will conserve only what we love, we will love only what we understand, and we will understand only what we are taught.” – Baba Dioum (posted at the Friends for the Environment)

Anolis sagrei female on the ground (photo by K. Winchell)

Anolis sagrei male (photo by K. Winchell)

Our main goal on this trip was to capture Anolis sagrei to continue ongoing research into the amazing diversity among islands in this species. We were immediately struck by how much smaller the Anolis sagrei on Abaco were compared to those on the other islands we have been to. I was also struck by how many A. sagrei used the ground. I normally study Anolis cristatellus, and although they are the same ecomorph, I rarely see A. cristatellus on the ground. I also don’t recall seeing A. sagrei frequently on the ground on Bimini or Eleuthera. So observing these lizards, particularly the females, on the ground at such a high frequency (they literally scattered as I walked!) was very surprising. Is this common on other islands with A. sagrei and I just haven’t noticed before?

Anolis smaragdinus (photo by K. Winchell)

Anolis distichus (photo by K. Winchell)

As with any good field trip, we also encountered a great diversity of herps. Although the only native anole to Abaco is A. sagrei (according to Powell and Henderson 2012), we also saw plenty of Anolis distichus and a few Anolis smaragdinus. We also saw the invasive Cuban tree frog (Osteopilus septentrionalis), the native Eleutherodactylus planirostris, and plenty of curly-tails (Leiocephalus carinatus). No live snakes to report, although we did come across a couple of roadkill Cubophis.

Eleutherodactylus planirostris (photo by K. Winchell)

Osteopilus septentrionalis (photo by K. Winchell)

Leiocephalus carinatus (photo by K. Winchell)

Although we found no Sphaerodactylus, we did find plenty of non-native Hemidactylus. Interestingly, Hemidactylus is not listed in Powell and Henderson’s (2012) list of West Indian amphibians and reptiles for Abaco. Can anyone ID this species (the photos are of two individuals) and tell me if this has been reported before for Abaco? Obviously Hemidactylus are widespread in the Caribbean, but I was surprised to see it absent from the species list for many of the Bahamas islands.

Hemidactylus on Abaco (photo by K. Winchell)

Herpetological Field Weekend in Bimini

By Sofia Prado-Irwin

On April 6, 2016

In Notes from the Field

I recently accompanied postdoc Anthony Geneva on a collecting trip to the small Bahamian island of Bimini for the shortest field excursion I’ve ever been on – four days in total. We were there to collect animals for a breeding colony, and luckily for us, the abundance of anoles on this tiny island is unbelievable. There are four species of Anolis present, each one representing a different ecomorph. Unsurprisingly, the brown anole A. sagrei is by far the most common, but we also saw our fair share of trunk-crown green anoles (A. smaragdinus), trunk anoles (A. distichus), and even a good number of twig anoles (A. angusticeps), which are notoriously hard to spot, so we were pretty excited. The island is also home to healthy populations of curly-tailed lizards (Leiocephalus), whiptails (Ameiva), and several species of gecko, so there was lots to see.

We collected during the day and at night, and were amused by the behavior of some of these lizards. My favorite find was this little guy sleeping under a leafy blanket. He almost fooled us, but that little curl of tail poking out gave him away.

We were also lucky to witness an adult angusticeps in broad daylight, the first time either of us had ever spotted a twig anole during the daytime. In true twig anole fashion, he kept subtly repositioning himself around the branch to hide, making it rather annoying to photograph him. Nonetheless, it was an exciting find.

Anolis angusticeps, taken by Anthony Geneva

On the other side of the spectrum was this very bold smaragdinus¸ who jumped from a leaf above and stood right next to me, giving me some solid side-eye before running back up the trunk.

For a quick four-day trip, we saw a really remarkable diversity of lizards, and we had a great time on Bimini.

Brown Anole Predation by Red-bellied Woodpeckers in Florida

By James T. Stroud

On March 22, 2016

In Introduced Anoles, Natural History Observations, Notes from the Field

While visiting relatives last week in Fort Myers (FL), anole enthusiast and avid wildlife photographer Kyle Wullschleger noticed a commotion among the trees while on an afternoon hike in a small neighbourhood nature preserve. On closer inspection he witnessed a group of red-bellied woodpeckers (Melanerpes carolinus) foraging on surrounding cypress trees, with a couple eventually appearing with their apparent target–non-native Cuban brown anoles (A. sagrei). He recalls some of the details:

“The photos from the sequence aren’t all that fantastic because I cropped in so it really just shows the behavior. The whole sequence the woodpecker was basically just slamming the anole against the tree and then trying to pick it apart – it was hard to tell what exactly it was doing, but I believe it eventually swallowed it whole before flying away–it hopped behind the tree so I couldn’t see it anymore.”

“There were at least five birds all moving up and down the lower third of the cypress trees just around the boardwalk I was on. They were moving around the trees without really knocking the wood, so maybe they were purposefully targeting anoles? I only saw successful predation twice, but the brush is so thick–it’s obviously happening quite a bit.”

Sean Giery had previously discussed the main avian predators of anoles in urban South Florida, but woodpeckers didn’t make the list. Woodpeckers do occur in urban areas of South Florida; a new one to add to the list?

On the importance of Dorsal and Tail Crest Illumination in Anolis Signals

By James T. Stroud

On March 4, 2016

In All Posts, Introduced Anoles, Natural History Observations, Notes from the Field

With a flurry of recent attention investigating how background light may influence the signalling efficiency of Anolis dewlaps (1,2,3,4), particularly those inhabiting low-light environments where patches of sunlight appear at a premium, it occurred to me that extended dorsal and tail crests may fall under similar selection. Below are some photos of Puerto Rican crested anoles (Anolis cristatellus) – a species in which males exhibit an enlarged tail crest and the ability to voluntarily erect impressive nuchal and dorsal crests during aggressive interactions (the mechanisms of which are detailed in this previous AA post) – that show how crests may contribute to signalling.

I have no doubt this thought has crossed the minds of many anole scientists before, particularly those current graduate students so successfully studying A. cristatellus and familiar with their ecology and behaviour (namely Alex Gunderson, Kristin Winchell, Matt McElroy, and Luisa Otero). Dewlaps are undoubtedly of primary importance to anole signalling and communication, but what are people’s general thoughts on the relative importance of other morphological features?

Battling Crested Anoles (A. cristatellus) in South Miami, FL

By James T. Stroud

On February 17, 2016

In Anole Photographs, Introduced Anoles, Natural History Observations, Notes from the Field

While out watching lizards last week with my undergraduate research assistant extraordinaire, Oliver Ljustina, and fellow SoFlo anole Ph.D. student Winter Beckles, we happened upon a pair of male crested anoles (Anolis cristatellus) ready to rumble! This is quite early – but not unheard of – in the season for the commencement of territorial disputes, so it was a surprise to see them locking horns so aggressively. This couple were battling fairly high in the tree, at approximately 3m.

Anyway, here are the pictures!

Anolis sagrei Survey Continued: Eleuthera, The Bahamas

By kmwinchell

On November 16, 2015

In Notes from the Field

I just got back from a short trip down to Eleuthera in The Bahamas where I was assisting Anthony Geneva (Harvard post-doc) in sampling lizards. Also along for the trip were Sofia Prado-Irwin (Harvard Ph.D. student) and Rich Glor (University of Kansas). We went with the main goal of sampling Anolis sagrei from four habitat types found commonly in the Bahamas as an extension of an ongoing project in the Losos lab (previous posts from: Rum Cay, Concepcion Island, Ragged Island, Bimini, Mangrove habitat, and Great Isaac Cay). Specifically, we were looking to sample Anolis sagrei in mangrove, secondary coppice forest, closed coppice forest, and beach scrub habitats. These habitats differ in the height of the canopy, density of the understory, and composition of plants.

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We focused entirely on the southern half of the island near Rock Sound and Cape Eleuthera. We were successful in sampling two beach scrub habitats, two mature coppice forest, one secondary coppice forest, and one mangrove habitat. We were able to catch all four of the anole species found on Eleuthera: Anolis angusticeps, Anolis distichus, Anolis sagrei, and Anolis smaragdinus. We also encountered a number of other native herp species: the Bahamian boa (Chilobothrus striatus), Ameiva auberi, Eleutherodactylus rogersi, curly tailed lizards (Leiocephalus carinatus), and the Bahamian racer (Alsophis voodoo), as well as a couple of non-native species: Cuban tree frog (Osteopilus septentrionalis), and Hemidactylus mabouia.

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In my own research I work with Anolis cristatellus, the Puerto Rican crested anole. I am always surprised when I catch A. sagrei by how much smaller they are than A. cristatellus, although very similar in appearance otherwise. On this trip, I was also surprised that the A. sagrei, as well as the A. angusticeps and the A. smaragdinus, appeared to be much smaller than those I had encountered on Bimini last spring.

We also found that the density of lizards was quite low compared to what we expected and what I had experienced in Bimini, both during the day and at night. In all four of the habitat types, we saw an abundance of hatchlings, juveniles, females, and small males, but relatively few full adult male A. sagrei. For A. angusticeps and A. smaragdinus, we encountered only a few individuals total during the week of sampling. This reminded me of an odd experience I had last fall in Puerto Rico with A. cristatellus. It was the same time of year and I had an extremely difficult time locating mature animals in sites where I had previously sampled large numbers during the spring and summer months. Instead, I observed a large number of very young animals and females. I’m curious if this is a coincidence or if perhaps there is a strong seasonal effect on either male behavior (i.e., reduced visibility outside of the mating season) or male abundance (i.e., reduced numbers because of mortality during the mating season). In other words, are the males still there, but hiding, or are they really lower in abundance in the late fall? Or maybe I was coincidentally unlucky on both trips… I am very curious to hear thoughts on this!

Anolis sagrei using coral ground habitat.

Finally, I want to end with a short natural history note on the habitat use of the A. sagrei in the mangrove habitat. In this habitat we observed A. sagrei using perches at drastically different heights: some were 6 feet up, others were on the ground. Interestingly, the ones on the ground did not appear to be in transit, but seemed to be using the pockmarked karst as perches, running into one of the many holes when approached. Has any one else observed this behavior before? It seems so different from the typical trunk-ground anole perch and behavior to me.

That’s all for now. Currently Anthony is sampling additional islands in the Bahamas along with Melissa Kemp (Harvard post-doc) and Colin Donihue (Yale Ph.D. candidate / Harvard visiting student). Best of luck to them, I can’t wait to hear how the rest of the trip went!

Blanchard Cave, a Window into the Late Pleistocene and Holocene Squamates from Marie-Galante Island (Guadeloupe Archipelago, Lesser Antilles)

By Corentin Bochaton

On November 11, 2015

In All Posts, New Research, Notes from the Field

Over the past few years, two European research programs developed an interest in the ancient fauna and environment of the Guadeloupe islands. The prospection for cave deposits led to the discovery of numerous accumulations of fossil remains documenting the Holocene and Late Pleistocene faunas of the archipelago, especially on the island of Marie-Galante, where three major deposits were discovered.

Blanchard Cave is one of these deposits. This cave contains the oldest fossil-bearing sedimentary layers of the island dated around 40,000 years before present and is an excellent complement to the two others cave documenting the Late Pleistocene fauna of Marie-Galante (Cadet 2 and Cadet 3).

After a test excavation in 2008 that revealed the potential of the site in term of fossil fauna, Blanchard cave was investigated between 2013 and 2014 in the framework of a European research program interested in the past environment and fauna of the Guadeloupe islands, the BIVAAG project. The three excavation campaigns conducted during this period allowed the precise documentation of the sedimentary filling of the cavities and the recovering of thousands of skeletal remains mainly attributed to frogs, lizards, snakes and bats.

The excavation work in the cave (Picture: A. Lenoble)

Welcome gifts from the bats… (Picture: C. Bochaton)

But collecting the fossils remains was not that easy and although the perspective of working in the Caribbean a few hundred meters from the sea could seem very attractive, the working conditions in the cave were far from pleasant. Mainly because the cave was inhabited from the ground to the roof by numerous cockroaches, rats, gnats and bats. Bats were extremely noisy, and proved to be extremely rude hosts. Another difficulty was the potential occurrence of histoplasmosis in the cave that led to the necessity of wearing a respirator during the work. Such masks make breathing difficult during the work and combined with the heat, humidity and other disagreements previously mentioned strongly impact your initial enthusiasm.

Once you overlook these difficulties, the sediment was extracted from the site and then washed and sieved in order to retrieve the small bones contained in it (the bones are usually smaller than 5 mm). The remains were then recovered and sorted, partly in the field (unfortunately this activity often kept the paleontologists outside of the cave and away from the bats), before being studied.

Washing and sieving of the sediments (Picture: M. E. Kemp)

Recovering of the fossil bones (Picture: M. E. Kemp)

The results of the study of the squamates remains collected in the cave can be found in a very recently published paper. To summarize the main findings, we found evidence of the past occurrence of at least ten species of snakes and lizards: four snakes: Antillotyphlops sp., Boa sp., Alsophis cf. antillensis and an undetermined colubroid; and six lizards: Anolis ferreus, Iguana sp., Leiocephalus sp, Thecadactylus sp., cf. Capitellum mariagalantae and Ameiva sp.. The stratigraphic distribution of these taxa in the site combined with previously existing data show that only two extinctions (Boa sp. and Colubroid ind.) are dated from the Pleistocene/Holocene transition and thus predate the arrival of humans on the islands around 5000 years ago. Then during the pre-Columbian times two new taxa appear in the deposits, Iguana and Thecadactylus. On the other hand, a massive faunal turnover began after the European colonization of the island. Indeed, at least six squamate genera (Leiocephalus, Capitellum, Ameiva, Antillotyphlops, Alsophis and Erythrolamprus), including all the snake genera, were extirpated between 1492 and today. Thus, 55% of the squamate genera present during pre-Columbian times went extinct over the past few centuries.

These results are further evidence of the current sixth mass extinction crisis and of the strong impact of humans on this insular fauna. However, Marie-Galante Island remains an isolated case because the past fauna of most of the Lesser Antillean islands remains poorly known and in most cases totally unknown despite the critical importance that such data may have in many fields to test inferences built on modern data.

Reaching Safety

By Eric Enrique Flores De Gracia

On November 9, 2015

In Anole Photographs, Notes from the Field

When somebody talks about roads crossing along natural forest, we could think about the perturbation this may cause to local fauna, especially in the Tropics. At least in Panama, wildlife crossings are not so popular in terms of design, deployment and monitoring. To my knowledge, the few existing ones are aerial and designed keeping in mind the crossing of monkeys or sloths for example. This issue came to my mind on the 3rd of November when I saw a Dactyloa insignis trying to cross an 8 m road traversing Santa Fe National Park, one of the pristine forest in central Panama.

Captured at Santa Fe National Park, Panama

It made three short attempts and looked clumsy when trying to run on the pavement puting him at risk of death, so we caught him and helped him reach the other side of the road.

Conception Island, Bahamas Lizard Survey

By Graham Reynolds

On August 4, 2015

In Anole Photographs, Notes from the Field

A view across Conception Island from the North.

Female A. sagrei

As part of our saga chasing Anolis sagrei around the Caribbean, we had the incredible fortune to visit the remote Conception Island Bank in the Bahamas. Conception Island and its associated small satellites are situated on their own bank, adjacent to Long Island which occupies a southeastern edge of the Great Bahamas Bank. Conception Bank and all its satellite islets are protected by the Bahamas National Trust as a National Park, and the bank is presently uninhabited though there is some history of human habitation in the past. Conception Island is quite small, totaling only 9 km by 2 km and has never been connected to any other island banks, meaning that the plants and animals here have almost certainly arrived via dispersal. Though located only 25 km ENE from the northern tip of Long Island, the 2400 m deep water and strong NW currents mean that the Conception Bank has a relatively depauperate terrestrial fauna owing to the vicissitudes of over-water dispersal. For example, in the latest comprehensive list of island herpetofaunal records, Long Island boasts 16 native extant species of reptiles and amphibians, relative to just five on the Conception Bank. Granted, this is potentially owing to lower sampling effort on Conception, as it is a remote, difficult, and expensive place to conduct extensive surveys. Indeed at least one record, that of the Bahamas Boa Chilabothrus strigilatus, is poorly documented and probably spurious.

An unusual dewlap color for A. sagrei

Alberto Puente-Rolon (UIPR-Arecibo), Anthony Geneva (Glor/Losos labs), Nick Herrmann (Losos Lab), and Kevin Aviles-Rodriguez (Kolbe/Revell labs) traveled with me to the Conception Bank aboard the Golden Bear out of Stella Maris, Long Island for two days in July 2015. Our goal was to sample Anolis sagrei from the bank, as well as generally conduct herpetofaunal surveys. We were particularly interested in verifying and attempting to build upon the last report of a herpetofaunal survey there (Franz and

Male Anolis sagrei displaying a light orange/ yellow dewlap in coastal palm scrub habitat.

Buckner 1998). While we expected Anolis sagrei to be present (it was), we also thought that the lack of a record for Anolis distichus might not stand up to our surveys. Alas, we checked multiple habitat types both day and night, from beach scrub to mature forests to mangroves and failed to turn up A. distichus. Though present on nearby Rum and San Salvador Banks (as well as Long Island), this species is curiously apparently absent from Conception.

Happily, we did find Anolis sagrei in abundance, and with some unusual features to boot. For one, the largest males are really quite large, tipping the scales at over 7 grams. Many males sported tall tail crests, and in the coastal scrub habitat, their yellowish dewlaps, combined with large size and tail crests, gave them an overall appearance very similar to Puerto Rican Crested Anoles (A. cristatellus). Interestingly, dewlaps in the forest appeared more traditionally sagrei-red, so we will see what our spectrometer and photographic data tell us about dewlap color variation on the bank. We will continue to update AA on our work with A. sagrei in the Bahamas.

Male Anolis sagrei with a large tail crest.

Kevin and Nick at work

Ragged Island, Bahamas, Lizard Research

By Graham Reynolds

On August 2, 2015

In Notes from the Field

Air approach to Great Ragged Island

We have been on the move quite a bit for our project on Anolis sagrei. On a recent trip to the Bahamas, Alberto Puente-Rolon (UIPR-Arecibo) and I were able to visit the remote Great Ragged Island, located at the southeastern edge of the Great Bahamas Bank only 115 km from the coast of Cuba. Great Ragged is the only inhabited island in the Ragged Island/Jumentos Cays range, a necklace of islands stretching in a sweeping concave arc from Long Island and the southern Exumas to the range terminus at Little Ragged Island. A mere 70 or so people live on Great Ragged, concentrated in Duncan Town, a small settlement perched atop a surprisingly high hill overlooking the deep ocean to the east and dark green expanses of mangroves to the west. Duncan Town is picturesque in the authentic Bahamian sense–brightly colored houses are dotted between crumbling ruins dating back a century or more. Chickens cover yards, and old stone walls snake from the town out into the bush. An artisanal and on-demand salt raking operation continues here, and small pyramids of bleached salt dot the edges of an expansive salina filled with shallow waters reflecting varying hues of pinks and reds in the morning sunlight.

Duncan Town salina and tropical dry scub habitat

Duncan Town salina and tropical dry scrub habitat shallow waters reflecting varying hues of pinks and reds in the morning sunlight. Photo by Alberto Puente.

Anolis smaragdinus from Ragged Island. Photo by Alberto Puente

The Anolis sagrei here are, as in most locations, abundant. We had great success locating them at night, where they sleep exposed on branches and reflect a pale glow in the beam of a headlamp. We sampled anoles from different habitat types on Great Ragged, including coastal Cocoloba uvifera stands, mangrove forest, stunted closed canopy tropical dry forest (where we had to crawl to make our way through), and highly disturbed goat pasture. We are excited to see how the population here compares to the rest of the range. In particular, we are wondering whether the sagrei on Great Ragged belong to the eastern or western Bahamas genetic lineage, which we have uncovered in previous work. The A. distichus here certainly resemble the populations in the western Bahamas, rather than the eastern Bahamas, to which Great Ragged is connected by the Jumentos Cays. We will follow up on these distichus observations in a later post. I will keep AA updated on what we find as we begin analysis of our data.