Nesting ecology of Black Caimans, <i>Melanosuchus niger</i> (Spix 1825) (Crocodylia: Alligatoridae), in the Lago doCuniã Extractive Reserve, Amazon, Brazil

The reproductive success of a population is the expression of life history traits such as fecundity andfertility, which are strongly affected by ecological factors. We investigated the use of nesting sites by female BlackCaimans, Melanosuchus niger (Spix 1825) during three consecutive nesting seasons from 2019 to 2021 at Lago doCuniã Extractive Reserve in the southwestern Brazilian Amazon. We examined factors influencing nesting ecologysuch as chamber temperature and applied multiple linear regressions to test hypotheses related to reproductive tradeoffsbetween different variables, such as female, egg, and clutch sizes. We identified trade-offs between egg width,hatchling size, and clutch size, suggesting that larger clutches contain smaller eggs, resulting in smaller hatchlings.A better understanding of crocodilian reproductive strategies and trade-offs are essential to predict the viability ofpopulations and to foster conservation initiatives at the Lago do Cuniã Reserve, where caimans are currently subjectedto a sustainable harvesting management plan.