It was definitely not a Chilmark native. Neither “local,” “washashore,” nor “visitor” quite describes the individual that was found last week in Menemsha.    

The creature in question -- a mourning gecko -- was jumping ship. It wasn’t a forced walk off the gangplank, but a leap into the hands of an alert Martha’s Vineyard Shipyard staffer who caught the beast as it was springing off a boat being hauled out for the season. The great escape was thankfully thwarted.

Maybe the gecko was a castaway, maybe not: its provenance will likely remain a mystery forever, since the boat had not been anywhere besides the Island, summering in Menemsha and wintering in Edgartown. There are no mourning geckos native to either town, or the Island, or the Commonwealth, or even much of the country.

Mourning geckos are native to the Indo-Pacific region, and have also established themselves in South America. In the United States, these geckos have found their way to Hawaii and Florida. They can be common residents in homes as pets, but not in the wild across the country. They are considered invasive in some regions of the world where their numbers have increased dramatically.

The rapid growth in mourning gecko populations and their breeding success can be somewhat surprising when you learn that males of the species are very rare. Mourning geckos were so called because of the dearth of males, which seemed sad to the scientists who named the species.  

In fact, female geckos do just fine without a partner. Females can and do breed well and often: every four to six weeks on their own, through parthenogenesis, also known as “virgin birth.” Males are not required to produce the mother’s clonal offspring.  

Many other adaptations help the mourning gecko survive. Its brown skin is cryptically colored and can adjust, adapting to the light and hues of its environment, not as famously as the chameleon but almost as effectively. This coloration deception helps the mourning gecko meld into its surroundings and thus blends in and avoids predators who rely primarily on sight to hunt prey.

The gecko also has toe pads, known for their setae (tiny hairs), that provide it with an exceptional ability to hold onto vertical surfaces.  Other interesting oddities include the lack of eyelids (its long tongue acts to clean and moisten its eyes), a tail that can separate from its body (to escape predators) and the ability to grow another tail after the separation.

Shipyard staff brought the gecko to Felix Neck for identification, mistakenly thinking that it was some sort of salamander. After verifying its identity, I asked whether the boat had ever been overseas (no) and if the owners might have had a pet that escaped (again no). Thus, the mystery of its appearance.    

The next question, of course, is what to do with it.

We certainly can’t return it to the wild or to the ship’s owners, since, through parthenogenesis, it could become a single parent again and again, and its children could again and again introduce a population to the Island that doesn’t belong and can’t possibly be fair to indigenous species. Feeding it to another animal is also an option, though I promised a friend’s son that we wouldn’t make it another’s dinner.

Re-homing it as a pet seems to be the only option, but buyer beware! These single geckos can multiply quickly.

I highly commend those Martha’s Vineyard Shipyard folk for being alert and conscientious, and forestalling the gecko before she could breed and spread her daughters across the Island.

Her life in a tank won’t be as glamorous as her former independent shipboard life; but at least she will not be responsible for turning Martha’s Vineyard into another paradise lost.

Suzan Bellincampi is islands director for Felix Neck Wildlife Sanctuary in Edgartown and the Nantucket Wildlife Sanctuaries. She is also the author of Martha’s Vineyard: A Field Guide to Island Nature and The Nature of Martha’s Vineyard.