Do olive ridley turtles select mates based on size? An investigation of mate size preference at a major arribada rookery

Abstract

We investigated mate size preferences in olive ridley sea turtles (Lepidochelys olivacea), one of the world's smallest and most abundant sea turtle species, using data from two years near a single mass nesting site. Even though past research has focused on many aspects of the reproductive biology of these turtles, not much is known about their mate preference and related behaviors. Our study focused on the large number of turtles that congregated for mating in nearshore waters before mass nesting. We captured, tagged, and measured 268 individuals (134 mating pairs), analyzing the correlation between male and female carapace length to test for assortative mating and found a significant positive correlation. Larger females produce more eggs, and larger males can have physical advantages during mating, and we think that these factors drive size-based assortative mating. We also observed frequent biting scar marks on females and multiple males attempting to mate with individual females, suggesting competition during mating. These findings enhance our understanding of olive ridley sea turtle mating behavior, specifically mate choice related to size.