VARIATION IN SIZE CLASS AND SEX RATIO OF MORELET'S CROCODILE IN WETLANDS OF CAMPECHE, MEXICO

Size class and sex ratio in crocodilians could potentially be affected by environmental conditions or by habitat use during different ontogenetic stages within a single population. in this study, we determined whether size class and sex ratio varied in relation to years and localities, and we considered the relationships between climate variables and sex ratio for a natural population of a Morelet's Crocodile (Crocodylus moreletii). We undertook surveys for crocodiles over 5 y (2007-2011) at three study sites within Los Petenes Biosphere reserve, Mexico. We estimated the age of captured crocodiles from snout-vent length using the von Bertalanffy model to estimate the year of hatching. although the overall sex ratio reported in this study was significantly different from parity, we find no differences of sex ratio among size classes, survey localities, or survey-years. We found annual variation in sex ratio from estimated age data, but the relationship between sex ratio and climate conditions was unclear. our results are a first step towards understanding size-class structure and sex ratios in the status and trends of populations of Morelet's Crocodile.