Eggshell of Caiman latirostris as Indicators of Environmental Disturbance by Human Activities

LEIVA, P.M.; SIMONCINI, M; BENÍTEZ, P.; MERCHANT, M.; LARRIERA, A.; PIÑA, C.I.

Skukuza

Congreso; XXIV Working Meeting CSG-UICN; 2016

CSG-UICN

Natural environments are affected by the growth of human populations and their (ie, expansion of agriculture). Today, this change persists and affects many species, including reptiles. In this study, we used Landsat-8 satellite images to asses anthropomorphized changes in the landscape during 2013 of five Proyecto Yacaré survey sites, and determined if these changes affect eggs characteristics and hatching success of Caiman latirostris nests. We collected 5 nests per site and then the eggs were incubated artificially. After hatching, we evaluated eggshell hardness, pore density, and measured the levels of heavy metals. Less antrophic sites (Fisco and Caminos natural reserves) produced bigger eggs. Although, we did not find relationship between the degree of human impact and hatching success of Caiman latirostris nests. The levels of heavy metals found in the eggshells from all sites was low (Al, Cu, Cr, Mn, Mo, Se and Zn), and there were very fex differences between sites. However, on the most anthropomorphized site (Lucero) we observed higher levels of Cr and Al. Future studies should expand the studied areas and continue to evaluate the relationship between the human-induced changes in habitats, the status of C. latirostris females, and the levels of contaminants in the eggshell, albumin and yolk, and the effects on the embryos.