Data from: The sex determination pattern in crocodilians: a systematic review after three decades of research
González, Edgar Javier et al. (2019), Data from: The sex determination pattern in crocodilians: a systematic review after three decades of research, Dryad, Dataset, https://doi.org/10.5061/dryad.1t2p835
1. Sex in crocodilians is not determined by chromosomes, but by egg incubation temperature, where different temperatures produce different clutch sex ratios. Two patterns have been proposed to describe these changes in sex ratios: a 100% female proportion at low and high temperatures with male predominance at intermediate ones (FMF) or a simpler pattern with a single female to male transition (FM). Over the last three decades, researchers have provided empirical information to support either of these two patterns in different species; however, no consensus has been reached partly because data has not been analyzed as a whole. 2. Here, we aimed at gathering the existing data on these patterns to provide models of temperature-driven sex-determination in those crocodilians studied so far. 3. A preliminary literature search allowed us to integrate a glossary of terms related with the phenomenon under study. With this, we created search queries that were entered into Web of Knowledge, Scopus, Scielo and Science Direct. Studies that reported results on the sexual identity of cocodrilian hatlings obtained from constant-temperature incubation treatments were considered. Using statistical models varying in their underlying assumptions, we evaluated which sex-determination pattern was best supported for the studied crocodilians and constructed species-specific and latitud-specific models. 4. Based on the 9030 sexed hatchlings studied throughout 30 studies, we show that the evidence supports a shared FMF pattern in all the crocodilian species thus far studied. We find that such pattern changes both at the species and population levels, but not at higher taxonomical ones. We provide single-species models of the FMF pattern, along with their variation at different latitudes. 5. These results suggest a lability of the FMF crocodilian sex determination pattern, a key feature under the present climate change scenario.