Seasonal Variation in Basking in Two Syntopic Species of Map Turtles (Emydidae: Graptemys)

The purpose of this study was to quantify seasonal variation in basking habits within 2 syntopic species of map turtles (Graptemys pseudogeographica kohnii and Graptemys ouachitensis sabinensis) in eastern Texas. Basking surveys were conducted twice per week from January 2005 to January 2006 along a 1.5-km transect of the Sabine River in Smith County. During this period, 312 observations of male and 178 observations of female G. pseudogeographica kohnii were recorded, while 2761 observations of male and 1334 observations of female G. ouachitensis sabinensis were made. Basking activity peaked in March (G. pseudogeographica kohnii) and May (G. ouachitensis sabinensis) with a peak of lesser magnitude for both species occurring in November. Within G. ottachitensis sabinensis, significantly more males than females were recorded basking throughout the year; however, in G. pseudogeographica kohnii significantly more males were recorded only during spring and fall.