Biodiversity in Belize
Biological Diversity in Belize
Site Search
 

 

Tokay Gecko Gekko gecko. (L) established on South Water Caye, Belize

 

Jan Meerman & Joe Garel

 

Introduction


South Water Caye is a small sand caye on the barrier reef and measures only 8.2 ha (20 acres). The caye is densely inhabited and in use by several diving operations. The dense human population has severe impacts on the ecology of the island and much of the island's natural vegetation has been cleared away and replaced by housing and Coconuts (Cocos nucifera). The island has a manicured appearance and any debris such as fallen palm-fronds are routinely removed by burning.

 

Reptile fauna


Naturally occurring reptiles included the anole Anolis (Norops) sagrei and the gecko's Aristelliger georgeensis and Phyllodactylus tuberculosus (Lee, 1996). During an August 1990 survey it was found that A. georgeensis was common while P.tuberculatus appeared scarce. Sea turtles used to nest on the island but the heavy human use of the island has put a stop to that. A newcomer on the island was the house-gecko Hemidactylus frenatus. First specimens of this species were not noted in Belize until 1993 (Meerman, pers. obs.) but this species probably arrived in the late 1980-ies. This species has a wide distribution in the Caribbean and "natural" colonization appears a likely explanation for the appearance and spread of this species. Another newcomer is the Tokay Gekko gecko. It was probably introduced to South Water Caye somewhere in the early 1990-ies.


The first Tokay on South Water Caye was observed in August 1994. The specimen was an adult and probably male. One year later no less than 13 Tokays were seen including immatures, indicating an established population. At that stage interviews were held with people working on the caye and it was learned that the animals were originally brought in by a tour operator and released. Observations between 11-13 / 18-20 July 2002 revealed a total of 9 adults and one subadult. One dead specimen was found. 3 adults were seen in buildings, the others were in coconut palms. The palm inhabiting individuals typically fled to the crown when approached. One huge specimen (> 30 cm) was observed inside one of the buildings. A single nesting aggregation was found under one of the buildings. This aggregation contained 6 eggs and numerous hatched egg fragments. One adult was noted beside the eggs for at least two days (guarding, egg-laying behavior?).

 

 

Of concern is the status of native reptiles of the South Water Caye. During the July 2002 survey the following species were observed:


Anolis (Norops) sagrei: A total of 12 individuals seen. Mostly on palms and fences. Appeared scarce but this species was not the focus of searches.


Aristelliger georgeensis: Total of 6 adults + 1 juvenile seen. Juvenile and one adult was found in head of young coconut palm. Other adults were found in buildings. One communal nesting site with eggs was found inside a hollow tree.


Hemidactylus frenatus: One specimen seen on a coconut tree, several heard.
The gecko Phyllodactylus tuberculosus could not be reconfirmed during this visit.

 

Species displacement

 

There are indications that the local gecko population is declining potentially as a result of predation by the aggressive Tokay. Although we have no exact data, we have the feeling that the number of A. georgeenis have gone down in the past years, also it was noted that many A. georgeenis now have large scars and or missing tails as opposed to what was previously noticed on the island or any other caye where the species was observed. The originally much scarcer Phyllodactylus tuberculosus may even have become locally extinct. At least we have been unable to confirm this species for a couple of years. Up to now there are no indications that the Tokay has found it's way to other islands or even the mainland. But when it does, it may well affect the local herpetofauna, several species of which are regional endemics.

 

General Tokay information


Tokay Gecko's are one of the largest gecko's alive today with a length of near 35 cm (14"). The skin is usually gray with several brownish-red to bright red spots and flecks but it has the ability to lighten or darken the coloring of its skin. The male is more brightly colored than the female and generally, and also tends to be slightly larger than the female. A conspicuous difference between the sexes is the small amount of swelling at the base of the tail of the male, due to the presence of the two hemipenes. Also, the males have visible preanal and femoral pores and postanal tubercules.


The species derives its common name from the loud mating call of the male. This loud "to-kay" sound is repeated multiple times (click link for call). During the breeding period, females lay eggs about every month. The hard-shelled eggs are affixed to a solid foundation. Commonly several females use the same egg-laying site, as was observed on South Water Caye.


The species has a wide distribution in South East Asia, but has also been introduced to the USA (introduced to Florida and probably Hawaii. In the Caribbean it appears to have been established on Martinique.




References:

Bartlett, R. D. 1988. The geckos of Florida--notes and comments. Notes North. Ohio Assoc. Herpetol. 16(3):2-10.

Boone, J. & B. Klusmeyer. Family Gekkonidae (Geckoes):
http://www1.embl-heidelberg.de/~uetz/families/Gekkonidae.html

Henderson etc. (1993) CARIBBEAN JOURNAL OF SCIENCE 29 (1-2): 128- 129.

King, F. W., and T. Krakauer. 1966. The exotic herpetofauna of southeast Florida. Q. J. Fla. Acad. Sci. 29:144-154.

Lee, J. C. , 1996, The Amphibians and Reptiles of the Yucatan Peninsula. , Comstock Publ. Assoc., Ithaca, New York.

Mckeown (1996) Field Guide Rept. Amph. Hawaiian Islands.

Stiling, P. 1989. Exotics--biological invasions. Fla. Wildl. 43(5):13-16.

Wilson, L. D., and L. Porras. 1983. The ecological impact of man on the south Florida herpetofauna. Univ. Kansas Mus. Nat. Hist., Spec. Publ. No. 9. 89pp.

Back to top

About Belize|Administrative|Publications|Species List|Projects|Links|HOME

  

Send mail to meerman@biological-diversity.info with questions or comments about this website.
Copyright 2002 biological-diversity.info and Belize Explorer Group Design Concepts
Last modified: January 30, 2005