Observations on the Ecology of Trachemys adiutrix and Kinosternon scorpioides on Curupu Island,Brazil

摘要

Brazil has an extensive coastline in the state of Maranhao,including many islands and a continental area called the "BaixadaMaranhense," where several turtle species of the familiesChelidae, Pelomedusidae, Kinosternidae, and Emydidae occur.Both Kinosternon scorpioides and Trachemys adiutrix occur onCurupu Island. Kinosternon scorpioides lives in both still andrunning water, frequently in areas affected by human activity,especially drainage canals (Pritchard and Trebbau 1984). Thisspecies is distributed from Mexico to South America, whereit thrives along the coast in Colombia, Guiana, Trinidad, andBrazil as well as the interior of the Amazon to Bolivia (Pritchardand Trebbau 1984). The genus Trachemys ranges from NorthAmerica into Central America (Savage 1966), southern Brazil,Uruguay, and Argentina (Vanzolini 1995) and has the largestgeographic distribution of any turtle genus in the New World(Seidel 2002). Trachemys adiutrix is an aquatic species thatinhabits permanent and seasonal bodies of water, and maymove great distances during the rainy season (Vanzolini 1995).The only published reference on Trachemys in Maranhao is theoriginal description of T. adiutrix from the northeastern region ofthe state (Vanzolini 1995). Information on the occurrence of K.scorpioides in the coastal region of Brazil consists of one recordreported by Pritchard and Trebbau (1984), who observed thespecies on Marajo Island, Para state. Because little is known ofK. scorpioides and T. adiutrix, we report data on selected aspectsof their biology in the coastal zone of northeastern Brazil. Wespecifically examined reproductive ecology (nesting behaviorand season) and population structure of these two species.