February 9th, 2012 by Marc AuMarc

Locally known as the woodslave, the turnip-tailed gecko (Thecadactylus rapicauda) is a large, native gecko that is seen less regularly than the introduced house gecko. It has huge eyes, partially-webbed feet and toes that are partially split and look like double toes.

Nothing being simple in St. Martin biology, since last year, there actually seem to be two species on the island. A new species (T. oskrobapreinorum) has been described that is known only from St. Martin, primarily distinguished by its coloration, light skin with distinct black spots. Although people have seen geckos like this on St. Martin for years, it has only recently been proposed as a new species.

Below are some photos of T. rapicauda. Given the close relationship between it and its newly-named relative, there is perhaps a bit of a mystery as to how they can coexist on the same island. For example, if T. oskrobapreinorum evolved on St. Martin from T. rapicauda how did it diverge if there was a population of T. rapicauda to breed with? Or perhaps T. oskrobapreinorum evolved in isolation on St. Martin and T. rapicauda was reintroduced more recently. If that’s the case, then does T. rapicauda represent a threat to T. oskrobapreinorum?

January 28th, 2012 by Marc AuMarc

A couple days ago I had the chance to check out the Puerto Rican crested anole (Anolis cristatellus) population at Port de Plaisance for a few minutes. The site of the first colony I located was a stand of ficus trees on one side of a wooden fence and the scrub on the other side at the edge of a lot that was being cleared. Depending on the overall distribution of the colony, it might be interesting to see how this impacts the viability of what seems to be a relatively restricted area of colonization. Ideally, the colony could collapse. The next step is to survey a broader area to determine the extent of the invasion.

January 28th, 2012 by Marc AuMarc

We attended the Nature Foundation’s Rockstars for Nature grand finale in January, presenting the Incomplete Guide to the Wildlife of St. Martin, and several interactive wildlife games for the visitors to play. The games included a search for cryptic critters (Find the Animal), identifying animals from extreme close-ups (What is it? and Whose Eye Am I?) and several other games. The event was loads of fun and it was great see people having fun while learning about the wildlife of the island.

January 21st, 2012 by Marc AuMarc

Dust bath may sound like an oxymoron, but it is something that many birds do to clean themselves and to get rid of parasites. House sparrows (Passer domesticus) are pretty social, and often take dust baths together, which is what you can see in the photos below. Originally from the Middle East, house sparrows have been following humans around for thousands of years and now live practically everywhere. In the Caribbean their range is still expanding. On St. Martin there are groups scattered around the island, mostly in urban areas.

January 20th, 2012 by Marc AuMarc

The black witch (Ascalapha odorata) is big, 6-7 inches in wingspan, but it isn’t actually black. I usually see this moth in shady areas like forests or ravines where it is a little dark, so it might look black, but it’s actually quite colorful. It is sometimes called a bat because of its size, color and bat-like flight, but that’s nothing more than a passing resemblance.

In various parts of the world, this moth may be considered a bad luck omen, a harbinger of death, a loved one’s soul returning to say goodbye or a sign that you will win the lottery. It’s easy to identify because it’s much bigger than any other moth on the island, but if you have any doubts, look for the eyespots on the front wings in the shape of the number nine. Or the number six if it is upside down, like the one in the photo below.

January 20th, 2012 by Marc AuMarc

The gray kingbird (Tyrannus dominicensis) can easily be seen all over the island, although it seems to prefer open areas, perching on trees and telephone lines and taking short flights to nab flying insects. It’s a talkative, graceful bird from the family known as tyrant flycatchers.

Today I saw a bunch of them while walking from Bellevue to Mont Fortune. I also learned what they do when they catch a large, feisty insect like a katydid. They hold it in their beak and bash it against a branch until it is easier to swallow. Check it out in the photos below.

January 20th, 2012 by Marc AuMarc

Most of the mangroves on St. Martin live at the edge of ponds, the lagoon or occasionally the sea. They’re uniquely developed to survive even when their roots are under water, often salty water at that. The mangrove below surprised me because it was one of a few that were growing in the shallow end of an abandoned swimming pool by Happy Bay.

Even though man has decimated the mangroves that historically covered much more of St. Martin, every once in a while I guess they get the last laugh. At least until the Happy Bay development gets rebuilt.

January 20th, 2012 by Marc AuMarc

There’s a mangrove tree in Étang de Cimetière in Grand Case that has been a home to countless iguanas and egrets over the last couple years, but is sadly dead or nearly so today. Below you can see the radical transformation over the last couple years.

April 2010 – Healthy Mangrove Hosting Egrets

January 2011 – Loads of Egrets, Lower Branches Bare

September 2011 – Nesting Over, Few Leaves Remain

December 2011 – No Birds, No Leaves, Fifteen Iguanas

January 2012 – The Egrets Return to Nest in the Bare Mangrove

It’s a pretty amazing progression, and I was surprised to see the egrets coming back to the bare tree. Of course, if the mangrove is totally dead, it will start rotting and probably collapse into the pond within another year or two. Probably there is a lesson in there for the humans of St. Martin, too.

January 19th, 2012 by Marc AuMarc

Karl Questel from Alsophis Antilles had told me they were here, but only in the last few days did I see them myself. While attending the Nature Foundation’s Rockstars for Nature event at Port de Plaisance on Sunday, I noticed a couple strange looking anoles. Today, I went back to confirm that they are Puerto Rican crested anoles (Anolis cristatellus).

The population seems to be fairly localized around a stand of ficus trees, but it’s impossible to be sure without surveying a broader area. For now, it’s the only place I know of on St. Martin where you can see three species of Anolis in one area. I doubt there’s a way to tell how they got here, but since it is a marina, it’s plausible that they arrived by boat. Here are a few photos.

While it’s exciting to see a new species here, the real question in the long term is how the newcomers might impact our native anoles. This is a particular concern because Anolis gingivinus lives only in the Anguilla bank (Anguilla, St. Martin and St. Barths) and Anolis pogus lives only on St. Martin. In the near-term, it could be an interesting opportunity to see how the three species interact. Caribbean anoles have been the subject of much study as an example of adaptive radiation. On islands with multiple species, each species will typically a slightly different ecological niche. Here on St. Martin, A. gingivinus is larger and tends to prefer more open areas, while A. pogus is smaller and prefers shadier locales.

For reference, here are photos of our native anoles from the same location:

January 7th, 2012 by Marc AuMarc

EPIC has been banding songbirds for about twelve years on St. Martin, making it a pretty unique long-term study for the Eastern Caribbean. The birds they study are primarily songbirds, and they include both year-round residents and winter migrants. The banding took place at Loterie Farm, at a stream flowing down the slope of Pic Paradis.

Each year, mist nets are placed in the same locations, and the data about captured birds includes weight, measurements, sex, age, presence of parasites and fat and muscle accumulation. Migrating birds, for example, accumulate fat and muscle before migration which is depleted over the course of migration. For local birds, size measurements can point to small differences in bird populations on different islands, or help establish the basic morphology of birds that have not been studied extensively.

Banding the birds can help establish migratory routes when the birds are recaptured either in the Caribbean or in their summer homes in North America. It can also give clues about the habits of birds, for example, catching the same bird in the exact same spot can indicate that birds maintain a very specific territory.

A long-term study, like this one, can also show patterns year-to-year or over longer periods of time that can illustrate the impacts of weather or the overall health of the ecosystem. This year, for example, water is very abundant in the survey area, which greatly reduced the number of birds captured. In a dry year, the nets are located at one of the few local sources of water. This year, with water everywhere, far fewer birds were visiting this particular stream.

On the first day I was there, I was able to help set up the nets, and Adam from EPIC explained the capture and data collection process. With few birds captured, only a single Antillean crested hummingbird while I was there, I also had some time to scout the forest for some interesting invertebrates, including a large katydid nymph, some tiny barklice and a variety of flies.

On my next day of banding, captures included a bananaquit (local) and an American redstart (migratory). Once again, there was plenty of time to look for interesting creatures in the forest and I found some beautiful green jumping spiders and a very well-camoflauged spider eating a caterpillar.