The very first day I went herping in Bangkok, I found an unusual-looking gecko:

Sri Lankan House Gecko (Hemidactylus parvimaculatus)

It didn’t look like a Spiny-tailed House Gecko or a Flat-tailed House Gecko or a Stump-toed Gecko or any of the other species that I knew lived in the city. I showed the picture to a friend who is an expert on Bangkok’s herps, and he guessed that it might be a Spotted House Gecko, a species that is usually only found down in southern Thailand. But we weren’t sure.

Just a week or two later, I was searching again close to my home and I found more of the unusual geckos:

Sri Lankan House Gecko Hemidactylus parvimaculatus adult

Now I was sure – they were NOT spotted house geckos. I went to the Field Herp Forum, an internet site where people post their herping finds, and asked them what it might be. Several herpers thought it might be related to a Brook’s Gecko, a species-group that is found over much of Africa and Asia, but not in Thailand. I looked at the pictures and realized they were on the right track. So I contacted Michael Cota at the Bangkok Museum of Natural History. He agreed that I had a new find for the city, and asked me to collect some samples. These girls were the lucky two:

Sri Lankan House Gecko Hemidactylus parvimaculatus adults and type specimens for description from Bangkok

Mr. Cota examined the lizards in the laboratory and determined that they were Sri Lankan House Geckos (Hemidactylus parvimaculatus), a species usually found on the island of Sri Lanka. They likely had gotten here accidentally by hiding in shipping containers of goods sent from Sri Lanka to Bangkok. By this time I’d found a couple dozen of the geckos near Oh Nut Soi 2, in Lumpani Park, and close to Sukhumwit Road Soi 60. Look on a map, and you can see the Khlong Toei docks are right in the middle of those three locations. In fact, I later found them close to Khlong Toei itself (as well as a couple new nearby locations), making it very likely that the docks were the original location and they spread out from there. I have yet to find these geckos anywhere more than 10 kilometers from the docks, despite extensive searching.

With the information we had, Mr. Cota and I were able to publish a scientific finding in the Herp Review journal, reporting the first ever discovery of Sri Lankan House Geckos in Thailand. The citation name is Cota, M. & J. Hakim. Hemidactylus parvimaculatus (Sri Lankan House Gecko). Geographical Distribution. Herpetological Review 42(2): 241.

Over time I realized that I nearly always find the geckos under pieces of concrete, usually on bare dirt. With five native species of geckos taking up most of the other space, concrete slabs on dirt is the only habitat niche that the Sri Lankan House Geckos have been able to make for themselves. It’s also a habitat niche that no one other than me was looking in – which is why no one else had found them, even though they’d certainly been in Bangkok for years already to have spread out as far as they did.

This shows how herping in even the most mundane of locales can lead to an exciting new discovery. Always keep your eyes open and photograph anything new that you see – and with a little luck, you might make your own notable discovery.