Tag Archives: predation

Predation of a Gecko by Anolis pulchellus in the British Virgin Islands

In the most recent issue of Herp Review, Anole Annals stalwarts Kevin de Queiroz and Jonathan Losos documented their account of observing an adult female grass-bush anole (Anolis pulchellus) consume a dwarf gecko (Sphaerodactylus macrolepis) on Guana Island, British Virgin Islands. The authors share their detailed report below:

Many primarily insectivorous lizards will eat other vertebrates on occasion, a behavior that has been reported in many species of Anolis. One unifying generality is that such carnivory is size structured, with the predator usually being substantially larger than the prey (Gerber 1999. In Losos and Leal [eds.], Anolis Newsletter V, pp. 28–39. Washington University, Saint Louis, Missouri). Not surprisingly, reports of anole carnivory pertain primarily to middle-sized and larger anoles. Here we report carnivory by a small anole of the species A. pulchellus. To our knowledge, this is the first instance of carnivory reported for this species and one of few for any similar-sized anole (the record noted by Henderson and Powell 2009. Natural History of West Indian Reptiles and Amphibians. University Press of Florida, Gainesville, Florida. 495 pp. is based on the observations reported here).

Fig. 1. Female Anolis pulchellus in the process of ingesting a Sphaerodactylus macrolepis.

Fig. 1. Female Anolis pulchellus in the process of ingesting a
Sphaerodactylus macrolepis.

We observed a female A. pulchellus (SVL ca. 38 mm) capture and consume a Sphaerodactylus macrolepis (SVL ca.18 mm) in the leaf litter at approximately 1430 h on 25 September 2006, on Guana Island, British Virgin Islands, near the head of the Liao Wei Ping Trail at roughly 18.47916°N, 64.57444°W (WGS 84). The anole jumped from a low perch (ca. 20 cm above the ground) to the ground and bit the gecko, which escaped and fled 15–20 cm to the opening of an ant nest. The anole attacked the gecko again, seized it in its mouth and carried it approximately 10 cm up a vine, a distance of 15–20 cm from the site of attack. Initially, the anole held the gecko upside down (i.e., dorsal surface facing down), biting it between the fore and hind limbs on the left side. Eventually the anole worked its grasp posterior to the base of the tail, still on the left side. At this point, parts of both the base of the tail and the left hind limb were in the anole’s mouth (Fig. 1). The anole then manipulated the gecko so that it was no longer upside down, but rotated about its long axis by roughly 90 degrees (the ventral surface of the gecko was then oriented forward relative to the anole) at which point it was biting the gecko at the base of the tail and possibly by the left hind limb; the anole eventually manipulated the gecko so that it held it tail-first in its mouth, dorsal side up, at which point the anole proceeded to ingest the gecko tail first (during this time, the tail itself broke off and was carried away by ants, which had been biting the gecko in several places since shortly after it was
captured by the anole). Total time from capture to complete ingestion was approximately five minutes.

Predation on Sphaerodactylus geckos has been reported in anoles of only a few species, none of which are as small as Anolis pulchellus (Henderson and Powell 2009. Natural History of West Indian Reptiles and Amphibians. University Press of Florida, Gainesville, Florida. 495 pp.). However, given the size discrepancy between the lizards in these two clades and their extensive coexistence across the Caribbean, we suspect that such interactions may occur with some frequency. Moreover, the high population densities of some Sphaerodactylus geckos (e.g., Rodda et al. 2001. J. Trop. Ecol. 17:331–338) and the diurnal activity of several species (Allen and Powell 2014. Herpetol. Conserv. Biol. 9:590–600) suggest that they may be important prey items for anoles.

Allen, K.E. and Powell, R., 2014. Thermal biology and microhabitat use in Puerto Rican eyespot geckos (Sphaerodactylus macrolepis macrolepis). Herpetological Conservation and Biology, 9(3), pp.590-600.
Gerber 1999. In Losos and Leal [eds.], Anolis Newsletter V, pp. 28–39. Washington University, Saint Louis, Missouri
Henderson and Powell 2009. Natural History of West Indian Reptiles and Amphibians. University Press of Florida, Gainesville, Florida. 495 pp.
Rodda, G.H., Perry, G.A.D., Rondeau, R.J. and Lazell, J., 2001. The densest terrestrial vertebrate. Journal of Tropical Ecology, 17(02), pp.331-338.

Tails of the City: Caudal Autotomy of Anolis cristatellus in Urban and Natural Environments

Lead author, Kirsten Tyler, reports on her recent Journal of Herpetology paper with K. Winchell and L. Revell:

Urbanization creates drastic changes to habitats leading to differences in microclimate, perch characteristics and distribution, and ecological communities (competitors, prey, and predators) when compared to natural (forest) habitats. Studies have found increased rates of mortality of many urban species due to generalist urban-tolerant predators such as raccoons, feral cats, and domestic animals (Ditchkoff 2006). Anolis lizards are able to voluntarily drop their tails (“autotomize”) when challenged by a predator, enabling their escape in many instances. The maimed lizards are able to regenerate their lost tails, though the replacement tail is a rod of cartilage and not the original bony vertebrae. The regenerated tail portions are often a different color and texture, and the lack of vertebrae / cartilage rod are clearly visible in X-rays.

We hypothesized that autotomy rates would be more similar between urban areas in different municipalities than to natural areas in the same municipality due to similar predator regimes in urban sites across the island. We compared the frequency and pattern (number of caudal vertebrae remaining) of caudal autotomy of A. cristatellus between urban and natural areas in Puerto Rico.

X-rays of our samples with an intact tail (A) and an autotomized tail (B).

X-rays of our samples with an intact tail (A) and an autotomized tail (B).

We sampled A. cristatellus from paired natural and urban sites in four Puerto Rican municipalities: San Juan, Mayagüez, Ponce, and Arecibo. The natural sites were high quality natural forests and the urban sites were high-density residential areas. Urban sites were dominated by asphalt and other impervious surfaces, had sparse tree cover, and a large fraction of potential perches were manmade surfaces such as walls and fences. We scored 967 X-rays from these eight sites for caudal autotomy and counted the number of remaining tail vertebrae. We tested for an effect of urbanization on caudal autotomy by fitting a logistic regression model with municipality (San Juan, Mayagüez, Ponce, Arecibo) and site type (urban, natural), and their interactions, as model factors, and body size as a covariate.

Our data shows that lizards found in urban sites have a larger probability of having autotomized tails.

Our data shows that lizards found in urban sites have a larger probability of having autotomized tails.

Interestingly, we found higher rates of autotomy in all urban populations compared to nearby natural areas. Differences in autotomy might be explained by differences in predator density and efficiency (Bateman 2011). For example, inefficient predators (those that more often than not fail to capture their prey) tend to leave behind more lizards with broken and regenerated tails (Schoener 1979). In addition, a greater abundance of predators could result in more predation attempts. Unfortunately, we did not collect data on predator abundances or community composition, so we cannot distinguish between these (non-mutually exclusive) explanations. Higher rates of autotomy in urban areas could thus reflect any of a variety of factors, including (but not restricted to) inefficient predators in urban areas, a shortage of refuges offering protection from predators, or an increase in predator density.

For lizards with autotomized tails, we found no significant difference in caudal vertebrae number between urban and natural sites.

For lizards with autotomized tails, we found no significant difference in caudal vertebrae number between urban and natural sites.

Lastly, we did not find that lizards with autotomized tails in urban areas had lost more (or less) of their original tail to caudal autotomy. Since regenerated tails cannot be autotomized past the original break point (i.e. cartilage cannot autotomize), this suggests that lizards in urban areas are no more likely to be subject to multiple unsuccessful predation attempts (resulting in caudal autotomy) than lizards in natural forest. Future investigation quantifying predation attempts or predator community composition in urban and forest habitats could help us better understand the source of this intriguing pattern.


Read the paper:

R. Kirsten TylerKristin M. Winchell, and Liam J. Revell (2016) Tails of the City: Caudal Autotomy in the Tropical Lizard, Anolis cristatellus, in Urban and Natural Areas of Puerto Rico. Journal of Herpetology: September 2016, Vol. 50, No. 3, pp. 435-441.



BATEMAN, P. W., AND P. A. FLEMING. 2011. Frequency of tail loss reflects variation in predation levels, predator efficiency, and the behaviour of three populations of brown anoles. Biological Journal of the Linnean Society 103:648–656.

DITCHKOFF, S. T. 2006. Animal behavior in urban ecosystems: modifica- tions due to human-induced stress. Urban Ecosystems 9:5–12.

SCHOENER, T. W. 1979. Inferring the properties of predation and other injury-producing agents from injury frequencies. Ecology 60:1110–1115.

Notes from the Field: Predation on Anolis sagrei on Isolated Cays in Abaco, Bahamas

Curly tail with brown anole tail visible from its mouth

Curly tail with brown anole tail visible from its mouth

Kayaking to the cays

Kayaking to cays

I was recently in Abaco, Bahamas with Losos lab post-doc Oriol LaPiedra and Ph.D. candidate Darío Fernández-Bellon from University College Cork, Ireland, to carry out some behavioral studies of Anolis sagrei on the island and its surrounding small cays. We kayaked (a highly recommended transportation mean for its lesser-impact on the marine ecosystem, not having to rely on the tide schedule, while allowing you to see rays and sharks and sea turtles!) our way out to islands that are known to have A. sagrei naturally existing alone, or with one of their natural predators, Leiocephalus carinatus.

Curly-tailed lizards are known to prey on A. sagrei and can have significant impact on anole behavior and adaptation. Twice I observed Leiocephalus capturing and consuming A. sagrei, one of which was an adult male and the other an adult female. We have also noticed that the A. sagrei on these island tend to perch higher and are seldomly seen on rocks or leveled ground compared to those on islands without curly tails, so this behavior could be an effect of Leiocephalus being present.

A female red-winged blackbird with a brown anole in its beak

A female red-winged blackbird with a A. sagrei in its beak

On a different island where Leiocephalus were absent, A. sagrei are still under predation pressure, this time by red-winged blackbirds nesting on the island. We observed a female blackbird with an A. sagrei in its beak waiting for us to leave the island so that it can feed its chicks. This observation suggests that A. sagrei on islands without Leiocephalus might still be under predation pressure by other species that might not be present on the island at all times. Also, predation pressure exerted by an aerial predator differs from that by a terrestrial predator or if both predators are present, so this might be a factor in morphological or behavioral changes in these lizards on these islands.

Anolis sagrei on one of the small cays

Other interesting observations include A. sagrei density on islands seems to be unintuitive. Some small islands with fewer perches hosted many more adult males and females than large islands did. Sizes of individuals also seem to vary greatly between different islands: small cay A. sagrei seem to be, on average, larger than those on mainland Abaco. Personally, I am unable to note major differences between islands which might have resulted in these observations. I’m excited to see if the data we’ve collected will give more insight into these observations as well as other behavioral results that will come from this study!

Brown Anole Predation by Red-bellied Woodpeckers in Florida


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?

Great Egret Eating a Crested Anole in Miami, FL

Here is a video taken by University of Miami PhD student Joanna Weremijewicz at the Fairchild Tropical Botanical Gardens in Miami, FL last Friday (20th March 2015). There have been lots of posts talking about the predation potential of egrets (and other wading birds) on anoles here on AA similar to this (1,2,3,4), but I think this could be the first one recording predation of A. cristatellus? Cool video!

Anolis huilae en Cacería (Anolis huilae Hunting)

Macho de Anolis huilae acechando su presa.

Macho de Anolis huilae acechando una presa.

Observaciones realizadas en mi finca (Ibagué – Colombia) de un macho de Anolis huilae acechando su presa y una hembra predando su presa. He tenido la oportunidad de observar individuos de ésta especie cazando orugas, larvas y moscas y, la manera como ellos invierten algún tiempo para acechar a sus presas para capturarlas . Aún se desconoce la dieta exacta de esta especie de lagarto endémico de la cordillera Central de Colombia.

Predación por parte de Anolis huilae

Predación por parte de una hembra de Anolis huilae

Editor’s note: Google translates the passage above as follows. It’s amazing how good this programs are getting!:

Observations made on my farm (Ibague - Colombia) of a male Anolis huilae stalking his prey and a female predating its prey. I have had the opportunity to observe individuals of this species hunting caterpillars, larvae and flies and how they spend some time to stalk their prey to catch them. The exact diet of this species of lizard endemic to Central Cordillera of Colombia is still unknown.

Nephila Predation on Brown Anole

A brown anole is caught up in the web of an Argiope orb-weaving spider

A brown anole is caught up in the web of an Nephila orb-weaving spider

Anoles eating spiders and spiders turning the table on anoles are well reported in both the literature and here on Anole Annals (1, 2). Recently, biologists Sarah French and Matthew Wolak of UC Riverside encountered this unfortunate Anolis sagrei that had been caught up in the web of an Nephila orb-weaving spider. Here’s what they had to say about the enounter: “We were at the Gumbo Limbo Nature Center in Boca Raton. Matt & I were walking down the boardwalk, totally creeped out by the abundance of spiders, when we encountered the anole caught in a web. He was still alive, but pretty well caught. The spider didn’t seem entirely sure what to do with it, but she seemed to occasionally bite it, which caused the anole to jerk & thrash about for a few seconds. It was hard not to feel sympathy for the anole, but native species trump exotic, and so we refrained from interfering! (But we also didn’t stick around for too long to watch).”

3P QuickCureClay Demo Video (With More Anole Sculptures!)

In my last post, I discussed my use of a new polymer clay, 3P QuickCureClay, in sculpting anoles.  Several commenters were interested in learning more about this medium and its potential for making models to assess predator marks.

I’ve now created a demonstration video of the clay which displays its unique properties and versatility (plus, newly finished anole sculptures make an appearance!):



Thin Snakes Eat Big Anoles

Blunt-headed treesnake eating an Anolis petersi.Photo by Elí García-Padilla from the March issue of Herp. Review.

The blunt-headed treesnake, Imantodes cenchoa, is renowned for its anolivory, but being a pencil thin snake, one might have thought that its carnage would be limited to the smaller members of anole nation. Not so, as two Natural History Notes in the March, 2011 issue of Herpetological Review report. García-Padilla and Luna-Alcántara report a treesnake eating a large A. petersi in the Los Tuxtlas region of Mexico (photo above), and Ray et al. provide the details of a 56 gram I. cenchoa that was found with a 19 gram A. frenatus and a 1.3. gram anole egg in its stomach. Justice was served in the latter case, as the snake died soon after capture, and an autopsy revealed a perforated stomach, attributed to the anole’s claw, presumably during post-ingestion attempts  by the anole to pull a Gordon and escape.

Cleaner Birds Removing Parasites From Anoles?

Here's a photo of a Carolina Wren that's caught a brown anole. But this story is something different. Photo from http://www.flickr.com/photos/24073599@N05/4545405419/

Brian Langerhans, he of mosquitofish fame (but with some anole credentials, such as here  and here), writes from Raleigh, NC:

A strange interaction was observed this morning and I’m wondering if you know what’s going on. There are a number of A. carolinensis that live around our house, and today something weird happened. It’s a pretty cool morning, but a big male was on a ledge on our porch. Two Carolina wrens flew over to the anole, the anole sat still while one pecked on it’s body and tail, and then extended it’s dewlap and opened it’s mouth for a while (but was otherwise still) as the other wren pecked around and in it’s mouth. Do you know what might have been happening here? You’d think the birds were harrassing the anole (and maybe it’s too cold for the lizard to fight back), but it didn’t seem like it. There’s no way they could have been cleaning it (like removing mites), right?  Any thoughts?

Anolis scriptus 4

Anolis scriptus- An Archipelagic Anole

Though they are not as flashy as some of their West Indian relatives, Anolis scriptus, the Southern Bahamas Anole, is an ecologically important and interesting component of the herpetofauna of the distal end of the Bahamas Archipelago. Small and brown to brownish green, they seem to be rarely photographed or discussed, so I thought they deserved a post on Anole Annals. These are individuals from the Turks and Caicos Islands- where they are ubiquitous on most emergent land- from the largest islands at over 290 square km to the smallest rocks with some vegetation. Interestingly, this species has been shown to modify its perch height in response to the presence of predators (more on predation in a later post). When curly-tailed lizards (Leiocephalus psammodromus) are around, the anoles are more arboreal (Smith 1994;1995). However, we have found this to be the case mostly on smaller islands, while on larger islands the anoles will still use the ground and lower tree trunks, even in close proximity to high densities of curly-tailed lizards.

JMIH 2011: More Anole Posters

The Sunday night poster session at JMIH 2011 had a few more anole offerings.  Melissa Moody from Iowa State reported on a laboratory experiment on the developmental and fitness consequences of varying Anolis sagrei egg incubation temperature and humidity.  Anolis sagrei eggs seem relatively robust to the variation experienced during this experiment.  Paul Cupp of Eastern Kentucky University asked whether ground skinks (Scincella lateralis) and green anoles (Anolis carolinensis) could detect chemical deposits from the Eastern Milk Snakes (Lampropeltis triangulum); he found evidence that the skinks could detect these deposits while the anoles could not.  Finally, Mingna Zhuang discussed comparative gliding performance of Anolis carolinensis and Anolis sagrei.  She found that A. carolinensis is a considerably better glider, perhaps due to the fact that it has a flatter gliding posture than A. sagrei.

A Highly Anecdotal Account of a Most Remarkable Anole

“You’ve gotta see this!” my fiancé Mark called to me one morning.  He was outside, which could mean only one thing: a wildlife encounter was underway.  Living in a semi-rural neighborhood in Florida, you never knew what you would see, from a mated pair of Sandhill Cranes walking down the street with their young, to Gopher Tortoises excavating burrows in the front yard.

I walked downstairs to the concrete area under our elevated house where Mark was staring at something on the ground.  I looked down to see a frog (Cuban Treefrog) with the tail of an A. carolinensis protruding from its gullet.

“I knew that lizard,” Mark said forlornly. Continue reading A Highly Anecdotal Account of a Most Remarkable Anole

Anolis Predation, Again

On a recent trip to Puerto Rico, I was fortunate enough to stumble upon an Alsophis portoricensis eating an adult male Anolis cristatellus. I was immediately reminded of Yoel’s post about A. sagrei and a black racer, and decided to set up my video camera. The entire event took about seventeen minutes, but sadly I missed the most interesting part – the capture. For those of you who don’t want to sit through the ten-minute clip, I recommend checking out the 3:50 mark [where the anole has his dewlap extended] and the last 30 seconds or so [to see both an interesting witness to the feeding event and the snake’s attempt to climb the tree after completing its meal].

Hungry for more information on Alsophis feeding behavior, particularly as it relates to anoles? Check out the work by Javier Rodríguez-Robles, Manuel Leal, & Richard Thomas, over at Javier’s home-page here.