Salinity Influence on Crocodiles (genera Crocodylia) in the Yum Balam Protected Area, Quintana Roo, Mexico

Student: 
Maria Joana Batalha

The influence of environmental factors such as salinity on crocodilian abundance and distribution remains understudied in sympatric estuarine populations. This is particularly significant as salinity in these locations is highly susceptible to vary due to both the inherent habitat characteristics and climate change impact. The topic of how to distinguish between Crocodylus acutus and Crocodylus moreletii throughout their sympatric distribution has also risen in prominence, with cryptic hybrids typically presenting phenotypical similarity to one of the parental species, with or without atypical characteristics.
Most studies on head morphology between these two species have focused on skull shape differences without including admixture individuals, with this work being the first to compare head shape of live individuals of the three groups. We quantitively and graphically demonstrated there are three distinct head shapes while not finding any relation between this change and varying salinity. This study also created a crocodile abundance indicator and reported salinities for the estuarine habitat of Yum Balam Protected Area in the dry season, highlighting the potential for hybrids to have higher salinity tolerance. Our results underscore the importance of a multidisciplinary approach for effective conservation and management of crocodile populations.