In Search Of Anolis lividus In The Shadow Of The Soufrière Hills Volcano

A view of the volcano as seen from the abandoned town of Richmond Hill. Photo: Jim Hewlett

As “anolologists” we think of the Lesser Antilles as one of the major treasure troves of colorful and extravagant lizards. They have been the subject of many AA posts (here, here, here, and here, among others). While gazing at anoles dewlapping in swaying palm trees, it’s easy to forget that the Lesser Antilles are a volcanic arc. However, on the tiny island of Montserrat where Anolis lividus is found, the volcano is alive and active. After a long dormancy the volcano awoke in 1995 and, within only a few weeks of activity, the capital city of Plymouth and surrounding areas were carpeted in several meters of pyroclastic material. Today Plymouth is a modern-day Pompeii. Plymouth is also the type locality for Anolis lividus, a charismatic medium-sized lizard from the bimaculatus clade of Lesser Antillean anoles. It was extraordinarily abundant in Plymouth and surrounding areas, according to Skip Lazell’s 1972 monograph in the Bulletin of the Museum of Comparative Zoology. Since 2009 I’ve been surveying this lizard across the island, and have tried to find it as close to the volcano as I can get.

A picture by the Montserrat Volcano Observatory showing the impact of volcanic dome collapse along the Belham River Valley in January 2010.

Figure 1. Map of Montserrat. Some of the localities where I have sampled A. lividus are shown with black dots. Sites where A. lividus was sampled before the eruption are shown with stars. The exclusion zone boundary is shown with a solid line. The volcano is shown with a triangle.

The permanent exclusion zone is a fenced off region south of the Belham River Valley (Figure 1). The Belham is a barren bed of ash and sand that gets periodically assaulted by pyroclastic flows. It effectively separates the habitable part of Montserrat north of the riverbed from the dangerous part of the island to the south. Getting into the exclusion zone is no easy task. While the volcano is active, access is tightly regulated. Even in the best of times, getting into Plymouth is impossible and so we can only survey in the ruins of towns outside of Plymouth, such as Richmond Hill and Fox’s Bay. In summer of 2009 I went into the exclusion zone with a surveying team of geologists. I was allowed to accompany the team, but had to go where they went, and could not stray far from the vehicle. I was able to find 2 lizards on that trip, a mating pair in a tree just outside of Richmond Hill. Since then I made a brief jaunt in January 2011 with the chief of police and couldn’t find any lizards. Both trips were frustratingly brief. With the geologists I could only look in the immediate vicinity of where they stopped, and couldn’t survey the trees and vegetation along the road. In January 2010 I only had 45 minutes to survey a single part of Richmond Hill. After the dome collapsed in 2010, the volcano has been surprisingly quiet. As a result, much of the exclusion zone is open to the public during the day. This time, I was able to take my time, go where I preferred, and I brought reinforcements.

We searched high and low, in and out, and all around for Anolis lividus.

Along with Jim Hewlett, a Professor at Finger Lakes Community College, his three students, and Troy, who can only be described as an “opinionated” ex-pat, we traveled into the exclusion zone for a few hours of herping. We visited all my old sites from 2009 except for St. George’s Hill, which is still off limits. We visited new sites at Fox’s Bay and in Richmond Hill. We searched outside and inside abandoned homes. We drove at a snail’s pace between sites in two cars so that we could all scan the bushes, trees, and fence posts for lizards. I kept my noose in my lap, certain that I would find Anolis lividus everywhere. I mean, the volcano has been quiet for almost two years, anoles can disperse pretty quickly, and the habitat looked better than I had ever seen it – barely any ash, no rancid sulfur smell in the air. They should be here. Right?

The Belham River Valley, which separates the inhabited region in the north from the exclusion zone in the south.

I can report that they are nowhere to be found! A team of six working to find the slightest glimmer of green scales in the sun came up dry. It was a frustrating endeavor, I can assure you. It was also frustrating leaving the exclusion zone, as we were locked in by the police department. A policeman keeps a log of visitors to the exclusion zone. Apparently we tried to leave during the shift change. It is possible that the Belham River Valley prevents dispersal from the north, which abounds in A. lividus, to the southern region even if the conditions permit habitation. It is a wide, barren ashbed with little vegetation that gets periodically assaulted by pyroclastic flows and lahars, or landslides of ash and volcanic material.

As we tried to leave the exclusion zone, we discovered that we were locked in... for much longer than ten minutes.

The ex-pat Troy told me that there are anoles in Isle’s Bay, which is on the volcano’s side of the Belham, but outside of the permanent exclusion zone. After the volcanic dome collapse of 2010 conditions have been quiet enough to permit Isle’s Bay, a small residential community with nice villas, to reopen. While it is not in the permanent exclusion zone, it is in Zone B, which gets periodically evacuated when activity rises.

Anolis lividus. Northeastern Montserrat. Photo: Jim Hewlett

It would be intriguing if A. lividus is in Isle’s Bay but not in the permanent exclusion zone. The habitat in Richmond Hill and Fox’s Bay appears quite suitable, and it is not very different from sites in the north where A. lividus is found, except for a bit more acid rain damage. Are humans mediating recolonization south of the Belham to the community of villas in Isle’s Bay? Given enough time, will they colonize other parts of the exclusion zone? It’s only a rumor, and I was unable to visit Isle’s Bay on this trip to check if they are present, but it is an intriguing possibility. To all you anolologists visiting Montserrat – I encourage you to find out! In the meanwhile, here are some photos of Anolis lividus that we saw in the northern half of the island during this trip. There, they are still abundant and charismatic, making this trip as exciting as ever.

Anolis lividus. Northeastern Montserrat. Photo: Jim Hewlett

Anolis lividus. Northeastern Montserrat. Photo: Jim Hewlett

Anolis lividus. Northeastern Montserrat. Photo: Jim Hewlett

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Martha Muñoz

Martha is a postdoctoral researcher in Sheila Patek's laboratory at Duke University. She received her Ph.D. at Harvard University, where she studyied the evolutionary ecology and thermal physiology of anoles, focusing on the cybotoid anoles from the Dominican Republic. Martha serves as Conference Editor for the Anole Annals.
Website: www.marthamunoz.weebly.com

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