The Daily Bucket is a regular series from the Backyard Science group. Here we talk about Mother Nature in all her glory, especially the parts that live nearby. So let us know (as close as you are comfortable) where you are and what's going on around you. What's the weather like? Seen any interesting plants, bugs or critters? Are there birds at your feeders? Deer, foxes or peahens in your yard? Seen any cool rocks or geological features? Post your observations and notes here. And photos. We like lots of photos. :)
Florida is the land of invasive species. Because of our status as a center for the importing of exotic pets and houseplants from overseas, and our neo-tropical climate, we have been invaded by everything from kudzu plants to Burmese pythons. One of our invaders is a large unfriendly lizard from southeast Asia with a not-very-polite nickname, that is very popular in the pet trade.
Tokay Gecko
The Geckos are one of the largest groups of lizards, with at least 1500 different species scattered in tropical and temperate areas around the world. Nearly all are nocturnal, sleeping during the day and hunting for insects and smaller animals at night. They are best-known for their complex toe pads which allow them to walk up walls and across ceilings, seemingly defying gravity. The Geckos are also unusual among reptiles in that they communicate vocally, calling to each other in the night using chirps, squeaks or barks.
One of the most familiar of this group of lizards is the Tokay Gecko, Gekko gecko, which can be found from southeast Asia down into Indonesia and up into India. (The Bangladesh population is sometimes considered to be a separate subspecies.) This is a large lizard, reaching over a foot long (Tokays are the second-largest species of Gecko in the world), with an attractive color pattern of slate blue or light purple covered with rust-red or orange spots. They have the ability to make their skin patterns lighter or darker, both to blend in with their background and as a method of communication.
Tokays live in rainforest areas, clinging to tree trunks and hunting insects, tree frogs, and smaller lizards at night. The large eyes, with vertical pupils like a cat, give excellent night vision, and like most geckos they have no eyelids--they periodically lick their eyeballs with their tongues to clean them.
The name "tokay" comes from the loud two-part clicking call that the males make during the breeding season, both to attract females and to warn other males away from their territory. During the Vietnam War, American soldiers who heard the geckos calling at night thought that it was Viet Cong guerrillas taunting them with rude English insults from the jungle, and the Tokay Gecko was widely known as the "fuck you" lizard.
Tokay Geckos reproduce by laying eggs, often in pairs. It is not uncommon for breeding females to lay a pair of eggs every month for four or five months in a row. The eggs have sticky hard shells when laid, and are attached to the underside of a tree branch and guarded by Mom until they hatch. The hatchlings are around 2 inches long. It takes about three years for a young Tokay to reach adulthood. In captivity, they have lived up to 12 years; wild lizards probably live 8-10 years.
What Tokay Geckos are most famous for among reptile-keepers, however, is their sheer belligerence. They may possibly be the meanest lizard you will ever see. They are fiercely territorial and do not tolerate the presence of other Tokay Geckos in their area, or any other intruder--including human keepers. The males, which are larger and brighter than the females, are particularly belligerent. When annoyed, Tokays will puff themselves up with air and gape their jaws at the intruder, and if pressed, they will not hesitate to bite. The jaw muscles are very strong, and an adult Tokay can give a very painful bite that can easily draw blood, and once clamped down on you, it can be hard to get the lizard to let go. Some people have labelled them "the reptilian pit bull". In tropical Asia, where the Tokays are often encouraged or even deliberately released into homes as a way to control cockroaches, spiders and other pests, the humans learn quickly to keep their hands away.
Nevertheless, despite their aggressiveness and their ready willingness to chomp on you, the Tokay Gecko's large size and attractive colors made it enormously popular in the exotic pet trade during the 1990's. They were imported from Indonesia and the Philippines by the thousands, often selling in pet shops for ten dollars or less.
Although pet Tokays are tough and easy to care for as well as pretty to look at, new and inexperienced reptile keepers soon discovered that the Tokay Gecko is entirely willing to bite the hand that feeds it, and then not let go. Soon, keepers with sore fingers were releasing their now-unwanted pets into the backyard. In the cold northern areas of the US, the lizards quickly died. But in the warmer areas, the tough adaptable Tokays thrived. Today, introduced Tokay Geckos have become established throughout the subtropical parts of the US, particularly Hawaii and Texas. In Florida, small escaped colonies from commercial breeders had been established near Gainesville in the mid-60's, but it wasn't until the reptile pet craze of the 1990's that the state began to be flooded with imports and escapees. Today the lizards are breeding in at least ten Florida counties, including the Keys. They are often found in houses, running across the ceilings at night, and it's not unusual to hear the distinctive "fuck you" gecko call from inside the walls or up in the attic.
For some, the geckos are welcomed, as a means of keeping the house bug-free. Indeed, it was not uncommon for Florida residents to buy a couple Tokays for the specific purpose of releasing them inside to eat cockroaches. But the Tokays also make meals of our Florida tree frogs and smaller lizards, including our smaller native geckos. So far, state wildlife officials consider the introduced Tokays to be a mild threat to native wildlife, but are not making any efforts to eradicate the Tokays, preferring to put their resources into more threatening invaders. The Tokays, once released, tend to stay in the local urban area, preferring to live inside people's houses rather than dispersing out into the surrounding wild countryside, and that limits their spread and prevents them from being a danger to most of Florida's native wildlife. So until the Tokays become more of an actual threat, state wildlife officials, like many Florida residents, are inclined to a "live and let live" policy towards them.
In some areas in their native Asia, Tokay Geckos are eaten as a local delicacy. They are also used in traditional Chinese medicine. They are not yet protected by any international conservation treaties, but they are legally protected in some countries as they have become depleted by the pet trade.
And now it is your turn--what's going on in your neck of the woods? Seen any mean foot-long lizards running up your walls lately?