Ecological and Behavioral Implications of Multiple Paternity in the Smooth-Fronted Caiman in French Guiana

The identification of genetic mating systems in a variety of species has challenged the previous view on animal mating patterns over the past decade, resulting in the identification of multiple paternity across all vertebrate classes. In crocodylians, all species that have been investigated demonstrate multiple paternity, which may represent the ancestral state of the clade. The smooth-fronted caiman, Paleosuchus trigonatus, is one of the last species whose genetic mating system has yet to be investigated. In this study, we analyzed genetic samples of the smooth-fronted caiman in French Guiana, a secretive species that is difficult to observe in the wild. Scute samples were taken from three populations and five groups of neonates that hatched shortly before. Microsatellite markers were used to infer the minimum number of fathers that sired each clutch. Our results clearly show that multiple paternity was common, with 60% of the sampled group of neonates showing a minimum of two sires. The potential ecological and behavioral implications of this finding are discussed, as well as recommendations for future research avenues to elucidate this cryptic species' mating behavior and environmental constraints.