Last week our own Ryann Rossi (mangrove extraordinaire) encountered one of the stranger animals of The Bahamas while visiting San Salvador, a blindsnake. I still haven’t been able to uncover blindsnakes on Abaco, but I thought I would share a bit of information on this group of snakes because: 1) they are largely unfamiliar to most people and are easily overlooked, 2) they’re unusual, and 3) because at least two of the Bahamian species are endemics, i.e., found nowhere else on earth.
Evolutionary History – Blindsnakes (Scolecophidia) are unlike other snakes. They are among the earliest snakes with more typical snakes (Alethinophidia) splitting from blindsnakes soon after snakes first evolved from lizards (~150 million years ago ). It’s easy to recognize this distinctiveness, blindsnakes have several ecological and morphological traits that are unusual within the rest of the snakes. Their appearance and diet are highly specialized and unlike any other vertebrate group. Despite this highly specialized set of adaptations, they are fairly successful, as evidenced by their wide geographic range, diversity, and deep history.
Range – Blindsnakes can be found in just about any tropical or warm temperate area of the world including remote islands in the South Pacific. Across this range there are likely hundreds of species while perhaps only less than a hundred are currently recognized. Within The Bahamas five species are currently known/recognized. Of these, one is introduced and the rest are native. See below for more information on which Bahamian species are found where.
Appearance – Most species are less than 30 centimeters long (smallest is 10cm) although some can get up to a meter long (none in The Bahamas). Their shape is long, cylindrical and thin, giving them their other common names: thread snakes or worm snakes. Coloration can vary from pink to black, sometimes accompanied by blotches or thin stripes along their back. But whatever their color blind snakes are smooth and shiny with small even sized scales covering their entire body. Their heads are small and non-distinct so you’d have to look fairly close to tell which end is which. But if you do get in close you can typically make out two small dark spots on the top/side of their heads. These dark spots, covered with thick scales are their eyes. It’s unlikely that these eyes do more than just detect whether their environment is light or dark – a very rudimentary kind of vision. On the underside of their head is the mouth. Blindsnake mouths are unlike a typical snakes mouth. They are usually fairly narrow, small, and underslung – they remind me of a sharks mouth more than a regular snakes mouth. In fact their mouths are so small that they could never bite a human – which they won’t even try. Like their heads, the tails are indistinct and short (just a little bit past their cloaca) and typically end in a point which they use to grip the soil (they do not sting!).
Habitat – The habitat of blind snakes surely varies across their large geographic range (basically found in any tropical climate). However, they are entirely fossorial, spending their lives underground in loose soil or slinking through the tunnels and chambers of other invertebrates like ants and termites. These snakes may also be found in fallen logs giving them another local common name of ‘wood worms’. However, blindsnakes will come to the surface occasionally after rains or can be found by flipping rocks and logs. In fact, most of the blindsnakes I’ve found were under rocks (besides one I found on the sidewalk in Downtown Miami).
Diet – Blindsnakes eat invertebrates with a particular emphasis on ants and termites (see recent media frenzy about how they tackle their prey).
Reproduction – It seems that most, if not all species are egg-layers, but besides that I don’t know much about blind snake reproduction. One spectacular thing we do know that at least one species, the Brahminy blindsnake or Flowerpot snake (Indotyphlops (Rhamphotyphlops) braminus) is that the species is all-female and parthenogenic. Parthenogenesis is a form of asexual reproduction where the embyro develops without fertilization (sometimes called “virgin birth”). So these snakes, all of which are female, essentially produce clones of themselves and as a result, the entire population is comprised of genetically-identical females.
Bahamian Species – There are four native and one introduced species of blind snake in The Bahamas. However, it is likely that with more study of this cryptic little group that several more species will be described. Within the Bahamas we find that two species are fairly widespread and that two are highly restricted geographically. I can’t find common names for most of these species so bear with me while I try my hand at meshing latin names with some proposed common designations.
- Bahama blindsnake (Typhlops lumbricalis) is found throughout the Great and Little Bahama banks. Records are known from: Abaco, Grand Bahama, New Providence, Great Exuma, Little Exuma, Eleuthera, Cat Island, Long Island, Bimini, Berry Islands, Ragged Islands, and Andros (link to photo).
- Bimini blindsnake (Typhlops biminensis) is found on Great Bahama and Cay Sal Banks with records from Bimini, New Providence, the Berry Islands, Andros, Little Ragged Island, and Cay Sal. This species is also found in Cuba and Hispaniola, however, it seems that recent study shows that this may actually be at least 11 new species that had previously been overlooked as T. biminensis (link to paper). The ordinal description of T. biminensis suggests that the two species on found there partition their habitats between dry sandy coastal habitats for T. biminensis, and moist well-vegetated habitats for T. lumbricalis. (link to paper) (link to photo)
- San Salvador Blindsnake (Epictia (Leptotyphlops) columbi) is restricted to the Island of San Salvador and several of its small offshore islands. (Photo above)
- Inagua blindsnake (Typhlops paradoxes) is restricted to Great Inagua. Besides that, I couldn’t find much.
- *Flowerpot snake (Indotyphlops (Rhamphotyphlops) braminus is only recorded from New Providence. This introduced species is essentially distributed worldwide. Parthenogenic reproduction and tolerance of human-altered environments has contributed to it’s spread into tropical environments and even some temperate ones where greenhouses provide suitable climate. The name flowerpot snake is a reference to it’s habit of living among the roots of potted plants which has surely been largely responsible for transporting it around the world. These are quite easily found in developed areas of South Florida and can even be found in downtown Miami, apparently living among the roots of planted street palms. While this species has only been reported from New Providence (as far as I can tell) it has, or will, likely spread to the rest of The Bahamas via trade in potted plants. *Introduced
Well, I hope that was an interesting bit of information about one of the more cryptic vertebrate groups found in The Bahamas. These tiny, innocuous snakes are easy to overlook, so if you do come across one count yourself lucky. Having these termite-demolishing gems nosing about your garden can only be a good thing.
Mizuno & Kojima. 2015. A blindsnake that decapitates its termite prey. Journal of Zoology. (Link)
Powell and Henderson. 2012 Island lists of West Indian amphibians and reptiles. Bulletin of the Florida Museum of Natural History 51(2):85– 166. (Link)
Pyron et al. 2013. A Phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology 13:93. (Link).
Richmond 1955. The Blind Snakes (Typhlops) of Bimini, Bahama Islands, British West Indies, with Description of a New Species. American Museum Novitates 1734: 1-7 (Link).
Thomas and Hedges. 2007. Eleven new species of snakes of the genus Typhlops (Serpentes: Typhlopidae) from Hispaniola and Cuba. Zootaxa 1400:1-26. (Link).