Anolis planiceps from Trinidad. Image from The Herpetology of Trinidad & Tobago.
I am a West Indian amateur herpetologist and member of the AA family for the past 5-6 years.
I have travelled and photo-documented anole species along the Eastern Caribbean archipelago from Curaçao in the south to Anguilla in the north. In so doing, the colour patterns of each endemic species have instilled a special thrill to my senses.
Anolis aeneus in Trinidad. Photo from The Herpetology of Trinidad & Tobago
However, it is in my home island of Trinidad where a unique spectacle lays in wait of thoughtful analysis. In the urban areas of Port-of-Spain (especially in the suburb of Woodbrook), Anolis aeneus is common on fruit trees, running along house walls and even venturing through windows into home interiors, displaying their speckled glory.
Yet a mere 60 miles to the northeast in the rural village of Fishing Pond (my home village), the anole species A. planiceps rules unchallenged, without the presence of A. aeneus. However, the sighting of A. planiceps is as rare as hen’s teeth (to use a local saying), running along the ground to mount the nearest tree trunk when seen occasionally.
Instead, along my house walls (in that rural area), three lizard species predominate: Ameiva atrigularis and Cnemidophorus lemniscatus, both teiid ground dwellers, as well as Gonatodes vittatus, a gekkonid tree/wall climber. Occasionally, three other species can be seen: Polychrus marmoratus and Tropidurus plica, in the same family as anoles, as well as Mabuya bistrata, a skink in the Scincidae family. The last three are known to be tree/wall climbers. None of these six species are likely to be seen in the urban areas previously mentioned, where household cats and early morning birds seem not to deter the presence of A. aeneus.
My question, therefore: does interspecific competition for food and habitat (and maybe predation) from the other six rural lizard species keep A. planiceps from having larger populations? No other Eastern Caribbean island seems to harbour such an anomaly, except maybe St.Vincent with its elusive A. griseus which is in an environment with few other lizard species.
I await the views of the more learned and experienced members of the AA family.
In closing I’m aware that A. aeneus‘ home base extends to Grenada and the Grenadine Islands, while A. planiceps‘ base extends to Venezuela and Guyana.
See the volume: “A Field Guide to the Amphibian & Reptiles of Trinidad & Tobago” by John Murphy et al.
Cheers,
Reynold C. Boyce
- Why Are Some Anoles Common and Others Rare in Trinidad? - January 4, 2021
Renoir Auguste
Hi Reynold,
Great to hear from you and especially on this topic! I’m not as experienced as others on here but happy to chime in on this post, for the few that know me from AA.
The first thing that comes to mind to me is that Trinidad no doubt has a higher diversity of predators than the other Caribbean islands. Habitat (preference) also surely plays a role as Anolis planiceps does appear to prefer forested habitats, and not occupying urban areas – unlike the non-native species that have been introduced. Perhaps the highlight here is that the introduced species are not (for now) occupying similar forested areas as Anolis planiceps (that I know of). No doubt it would be interesting to investigate what are the factors that are playing a role in that, and whether that is something that will change!
Renoir
John C. Murphy
To add a few more ideas to Renoir’s post. Trinidad, Tobago, and Little Tobago are somewhat unique because they appear to have low numbers of native Anolis. All Anolis on Trinidad (aeneus, wattsi, sagrei, trinitatis, extremus, and possibly auratus) are introduced. Anolis planiceps is the only known native Anolis on Trinidad. On Tobago, both A. richardii and A. aeneus are introduced and until 2014 we thought Tobago had no native Anolis. However, I collected a twig anole similar in appearance to Anolis tigris from Venezuela – but it is genetically distinct. At this writing Little Tobago still has no known native anoles.
Anolis planiceps lives low on tree trunks and in the litter. The introduced anoles are more habitat generalists and use different niches and perches most of which are anthropogenic.