Growth rates of black caiman (Melanosuchus niger) in the Rupununi region of Guyana

Abstract

We conducted a study of black caiman (Melanosuchus niger) growth rates using data from a long-term mark-recapture study carried out in the Rupununi region of Guyana between 2005 and 2015. In contrast to previous studies, growth rates of black caiman declined with increasing size and this decline occurred more rapidly for females. Size-at-age models predicted that males and females reach asymptotic sizes of 178.2-189.0 cm SVL and 140.1-143.4 cm SVL, respectively. Our results suggest that growth rates of black caiman in the Rupununi region follow the same general patterns as for other crocodilians, and that disparities with previous black caiman studies may be largely related to density-dependent factors, among other possibilities. However, future studies that include large black caiman of known ages are needed to validate our findings.