Based on a long-standing program of field exploration initiated by the Smithsonian’s National Museum of Natural History and the University of Guyana, with further support from the American Museum of Natural History and the Royal Ontario Museum, a distinguished cast of authors, each with extensive experience in Guyana, has just published this enormous and useful monograph. Part of the abstract is appended below, but more importantly you may be wondering, just which anoles occur in Guyana? The answer is that there are at least five native species (auratus, fuscoauratus, ortonii, planiceps, and punctatus). They note, as well, that chrysolepis is reported to occur in Guyana as well, but all chrysolepis group specimens they examined turned out to be planiceps.
In addition, at least one Lesser Antillean species occurs in the cities of Georgetown and Kartabo. These invaders have been identified as both A. extremus from Barbados or A. aeneus from Grenada and the Grenadines, but the authors were unable to find any reliable morphological characters that could distinguish the two species, and thus could come to no conclusion about which species, or both, occur in several cities in Guyana, though they did note that Ernest Williams had identified many of the specimens in museums from Guyana as A. aeneus, as good a reason as any to attribute them to that species. The authors conclude “Clearly, the taxonomic status of Anolis aeneus versus Anolis extremus needs further investigation, both in areas where they occur in the West Indies and where they have been introduced on islands and the mainland of South America.”
Honorary anole friend Polychrus marmoratus also occurs in Guyana and is pictured above.
The first half of the two-page abstract:“Guyana has a very distinctive herpetofauna. In this first ever detailed modern accounting, based on voucher specimens, we document the presence of 324 species of amphibians and reptiles in the country; 148 amphibians, 176 reptiles. Of these, we present species accounts for 317 species and color photographs of about 62% (Plates 1–40). At the rate that new species are being described and distributional records are being found for the first time, we suspect that at least 350 species will be documented in a few decades.
The diverse herpetofauna includes 137 species of frogs and toads, 11 caecilians, 4 crocodylians, 4 amphisbaenians, 56 lizards, 97 snakes, and 15 turtles. Endemic species, which occur nowhere else in the world, comprise 15% of the herpetofauna. Most of the endemics are amphibians, comprising 27% of the amphibian fauna. Type localities (where the type specimens or scientific name-bearers of species were found) are located within Guyana for 24% of the herpetofauna, or 36% of the amphibians. This diverse fauna results from the geographic position of Guyana on the Guiana Shield and the isolated highlands or tepuis of the eastern part of the Pantepui Region, which are surrounded by lowland rainforest and savannas. Consequently, there is a mixture of local endemic species and widespread species characteristic of Amazonia and the Guianan Region.
Although the size of this volume may mislead some people into thinking that a lot is known about the fauna of Guyana, the work has just begun. Many of the species are known from fewer than five individuals in scientific collections; for many the life history, distribution, ecology, and behavior remain poorly known; few resources in the country are devoted to developing such knowledge; and as far as we are aware, no other group of animals in the fauna of Guyana has been summarized in a volume such as this to document the biological resources.”
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George Gorman
I collected in then British Guiana almost exactly 50 years ago. I was following up on reports from Beebe from about 50 years before that. I am certain that it was A. aeneus and not A. extremus that was fairly abundant along the coast, and near Kartabo.
Although aeneus is variable on the Grenada bank, it was not particularly difficult to distinguish (in life) from extremus of Barbados . Will look for an ancient photo to post…(but am not optimistic about finding it).