Category: New Research Page 34 of 66

Various anole species have been observed feeding on fruit (e.g., Herrel et al. 2004) and nectar (e.g., Colón Archilla 2010). On March 08, 2013 a brown anole (Anolis sagrei) male in my study area joined the growing list of lizards that have been observed feeding on plant sap. In our natural history note we not only describe how he fed on the sap of a banana plant (Musa sapientum), but also provided some notes on its display behavior.

Natural history notes like this usually describe single observations and may seem of minor significance. However, such observations contribute to our understanding of the natural history of the species in question, and can be an inspiration for study areas. And for that reason I encourage everyone to describe observations not only in Internet blogs, but also in journals such as Herpetology Notes and Herpetological Review. That way the information can be shared with a greater readership, and a record is left for generations to come.

NOTE: For those of you who are curious. I also wanted to know what the sap tasted like, so after touching some of it, I licked the tip of my finger. The sap had a very mild bitter taste, not something I would try to market as a soft drink.

A cobra in the Caribbean? No, the Hispaniolan brown racer, Haitiophis anomalus. As AA contributor Miguel  Landestoy reports in the September issue of IRCF Amphibians & Reptiles, more than half of all prey consumed by these snakes were anoles (Miguel: which species?). The article is a comprehensive overview of the natural history of this little known species, including much data newly collected by the author.

Apparently they can, as they graph above indicates: Captive brown anoles tilt their heads more when the call of a kestrel or hawk is played compared to their response to calls from a variety of more benign feathers. These results come from a study on 32 captive brown anoles conducted by Cantwell and Forrest and published recently in the Journal of Herpetology. We’ve had a bit of discussion on the hearing ability of anoles–we tend to focus on anole visual capability, but its clear that they can hear and thus the role of auditory capabilities in the lives of anoles deserves more study (as do their vocalizations).

A conference on the fauna and flora of the “Petite Antilles” was held in Martinique in 2010 and the resulting conference volume has just appeared and is downloadable. The papers are many and varied, covering all manner of organism and topics spanning a wide range of topics. I’d give a full report on the papers, but…most are in French. Of most interest to our audience is a paper from Roger Thorpe’s reporting further studies on contact zones between divergent A. roquet lineages on Martinique (we previously discussed what was formerly their most recent study). In addition, the Bobs Powell and Henderson, along with Gad Perry and others, have a paper on introduced species of the Lesser Ants, Michel Breuil has one on sphaeros, and there are a number of others of interest. The full Table of Contents is below.

The egg-laying biology of anoles is surprisingly little studied. Where do they lay their eggs? How often? Inquiring minds needs to know. And now a team of Japanese scientists led by Mitsuhido Toda has taken a small step to answer these questions.

Working with green anoles introduced to islands near Japan, the researchers brought ten females into the lab, amply fed and watered them, and saw where and how often they laid eggs. The lizards were brought into the lab in April and the first egg was laid in late May. Egg production increased until a peak in mid-August and ended in late October. Over the course of the season, females laid an average of 13.7 eggs. At the peak in August, females were averaging almost an egg a week.

Perhaps the most interesting part of the study was the cage in which the females were kept, which had a variety of available sites, including a potted fern and pots with wet and dry soil all at ground level, and another set of pots at a meter. Females strongly preferred the low-down pots to the high ones, and the pots with the ferns to those without. Among eggs laid in fern-less pots, all were in the wet soil and none in the dry soil. In the pots with ferns, eggs were often laid in the cup-shaped part of the plant in the center of the pot or between the eggs; eggs laid in the soil were from 0-50 mm below the surface, averaging 17 mm deep.

This research is part of a greater effort to learn the natural history of the green anole so as to eradicate it from the Japanese islands, where it is apparently having a devastating effect on the endemic insect fauna [1,2]. The researchers suggest that eradication efforts may be most useful in April, before the egg-laying season begins, and also suggest the development of artificial egg-laying sites, from which eggs can be harvested before they hatch.

She’s looking at me, probably thinking “Will he eat me”? And I’m looking at her, thinking “How many transposable elements are in your genome?”

I wanted to bring the attention of the Anolis community to our recent publication in Genome Biology and Evolution (Tollis and Boissinot 2013), where we study the population dynamics of those fascinating features of the green anole genome – transposable elements. Transposable elements (TEs) are important components of vertebrate genomes that may seem a bit esoteric to many readers of this blog, yet the Anolis genome has already yielded great insights into how the vertebrate classes differ in terms of these DNA parasites. In a nutshell, our paper shows how microevolutionary forces such as natural selection and genetic drift account for differences which are most obvious when we make macroevolutionary comparisons (i.e. between mammals and reptiles). Even though I’ve cut to the chase a little early, I thought it might be nice to discuss what we know about the study of genomic evolution, and how the Anolis genome is contributing to the field of comparative genomics.

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A. sagrei developmental sequence. Cover illustration from Sanger et al. (2012) Proc. B.

As discussed previously in the Annals, interest in squamate development is rapidly accelerating. Our growing community makes this an exciting time to study lizard development, especially in a comparative context. A recent study by Andrews et al. capitalizes on the increasing number of developmental resources for squamates to assess variability in developmental sequences across lizards and snakes. One of our favorite anoles, Anolis sagrei, represents one of the 21 species included in this study. The conclusions of this study speak to several long-standing evolutionary questions and opens up new avenues of investigation that may be of interest the readers of this blog. 


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A while back, we discussed whether bats eat anoles. It was recently brought to AA’s attention that anolivory by the common big-eared bat has been graphically documented in a 2011 PLoS One paper by Santana et al. Using videos taken at feeding roosts on Barro Colorado Island, the researchers documented three incidents of anoles being consumed, one of which is exhibited above (the anole looks like A. limifrons, a common species on BCI. Agree?).

As reported recently, these bats have become adept at scanning leaves for stationary prey, a major advance in bat foraging. One of the paper’s authors, Inga Geipel, confirmed that the lizards were caught during the night. As a result, apparently no sleeping anole is safe! The authors describe this foraging thusly: “M. microtis hunts on the wing, checking leaf by leaf in the forest while hovering up and down the understory vegetation.”

As for how they eat the anole, here’s the author’s description. Gruesome warning!!! Not for faint of heart:

Bats generally ate arthropods by repeatedly biting and crushing the prey’s head, or cephalothorax in the case of spiders, and then biting and discarding the wings, antennae and/or legs. Bats mostly used their premolar and molar teeth for the latter task, biting with one or both sides of the jaw. Once the prey’s head had been consumed and appendages had been discarded, bats consumed the thorax and abdomen biting with their molars and premolars and rotating the prey from one side of the jaw to the other.…Bats ate lizards in a similar fashion as they did arthropods, except that legs were also eaten along with the whole body. Bats started eating the lizard at the head (figure above), where they applied multiple molar bites. They continued to consume the lizard by chewing it with the molars using one side of the jaw, a behavior that continued throughout the consumption of the whole of the lizard. Apparently, lizards were eaten completely; the tail was not dropped.