Sexual Size Dimorphism (SSD) and Its association with IUCN-based extinction risk in turtles

Abstract

Turtles and tortoises are one of the oldest vertebrates with a long lifespan and they are among the most threatened group in the world. In this study we are investigated whatever SSD (Sexual Size Dimorphism) between male and female carapace width and height is linked to the extinction risk according to the IUCN classification. A dataset of 71 species from 350 species was examined in R with methods such as logistic regression, ANOVA and normality assessments. Our results indicated that SSD values were roughly normally distributed with a weak negative correlation of extinction risk. The ANOVA results showed no significant differences in SSD between threat categories and suggesting that SSD has limited predictive value for extinction risk for turtles and tortoise’s species. The study acknowledges limitations from not accounting for phylogenetic relationships and concludes that extinction risk is driven more by human pressures than by SSD.