Thursday, March 31, 2016

Red-eared Slider, Trachemys scripta elegans (Family Emydidae)

This is an invasive species in Trinidad.

Mohammed (2010) wrote, “Juveniles of Trachemys scripta elegans were imported in large numbers during the 1980s as part of the pet trade. Anecdotal evidence tells of several escapees across the island during that time. Their import was halted later in that decade. Currently, in addition to the Emperor Valley Zoo, there are at least three other privately owned collections of this American species where successful breeding occurs and of these, one is uncontrolled and weather determined. These specimens are possibly of 1980s stock, considering this turtle achieves sexual maturity at five years of age (Wibbels et al. 1998). There has now been resurgence in the popularity of this species and once again import has been permitted within the last four years. It should be noted that with the exception of these two adults, no other individuals have been recorded for the island. Communi­cation with J.C. Murphy revealed the existence of some individuals at a pond within the Arima Valley during the 1980s and 1990s. The natural distribution of T. scripta elegans occurs within the Mississippi Valley, from northern Illinois to south of the Gulf of Mexico (Lever 2003). There are records of its naturalization in over 30 countries, from Europe to Asia, Africa, South America, the West Indies, Australasia, the Indian Ocean and the Pacific Ocean. This species has also naturalized in a wider territory within North America (Lever 2003).The natural breeding habits and requirement for this species (Wibbels et al. 1998) are very similar to the local species (Murphy 1997) and it is possible that with the continued occurrence of escapes, they will colonize Trinidad. Similar to our local species, they are also omnivorous (Hart 1983), giving rise to the speculation of potential niche competition and poten­tially a new introduced exotic vertebrate to our drainages. Pritchard and Trebbau (1984) noted a much generalized diet for R. punctularia punctularia, feeding equally readily on land and in water. Our observations support this school of thought, but it should be noted that these feeding habits were aspects of specific captive behavior, and they were observed for Trachemys scripta elegans as well. The Emperor Valley Zoo has in the past housed this exotic species together with the agouti as a means of popu­lation control (the agoutis ate eggs of the turtles). Whilst the unnaturally high density of all species housed within the enclosure does not reflect the wild scenario, it demon­strates to some extent the potential niche competition and aggression the exotic species are capable of inflicting upon our native species.”

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