Morphology of the limb, shell and head explain the variation in performance and ecology across 14 turtle taxa (12 species)

Abstract

Given that morphology directly influences the ability of an organism to utilize its habitat and dietary resources, it also influences fitness. Comparing the relationship between morphology, performance and ecology is fundamental to understand how organisms evolve to occupy a wide range of habitats and diets. In turtles, studies have documented important relationships between morphology, performance and ecology, but none was field based or considered limb, shell and head morphology simultaneously. We compared the morphology, performance and ecology of 14 turtle taxa (12 species) in Mexico that range in their affinity to water and in their diet. We took linear measurements of limb, shell and head variables. We measured maximum swimming speed, maximum bite force and how often turtles were encountered on land, and we used stable isotopes to assess trophic position. We used these data to test the following three hypotheses: (1) morphology, performance and ecology covary; (2) limb and shell variables, like hand length, are correlated with swimming speed and the percentage of time spent on land; and (3) head variables, such as head width, are correlated with bite force and stable isotopes. We find support for these hypotheses and provide the first evidence that morphology influences performance and ecology in turtles in the field.

How aestivation evolve in turtles? a macroevolutionary and morphological approach

“…Our results suggest that shell morphology is correlated with the length of aestivation time across different families of chelonians. This result seems to be consistent with other studies, since the shape, size, and other morphological dimensions of the turtle shell are important factors related to ecological and performance aspects (Murphy et al 2016;Butter eld et al 2021). However, it is necessary to consider this result with caution, since the aestivation time in animals depends not only on the contribution of morphological traits, but also on the effect generated by several factors such as the quality of the aestivation shelters, intrinsic adaptations of each species (i.e., physiological and behavioral traits, see below) and environmental conditions.…”

Biology of Yucatán Box Turtles (Terrapene yucatana) in Northern Yucatán

“…Despite their great isolation from other North American Terrapene species and likely ecological distinctiveness, empirical studies of T. yucatana in the wild are lacking. Since Buskirk's (1993) thorough review of the species' natural history, based largely on his own interviews and field trips to Yucatán, mostly brief or anecdotal notes have been published on the species' distribution (Lee, 1996; Smith et al, 1996; Buskirk, 1997; Ázquez et al, 2000; Ochoa-Ochoa et al, 2006; Pfau and Buskirk, 2006; Legler and Vogt, 2013), behavior and performance (Pfau and Buskirk, 2006; Butterfield and Macip-Rios, 2019; Butterfield et al, 2021), trophic position (Butterfield et al, 2021), parasitology (Rodríguez-Vivas, et al 2016), and paleodistribution (Gotz and Sosa, 2011).…”

Home range of three turtle species in Central Yucatan. A comparative study

“…Vogt and Gúzman-Gúzman [ 20 ] also documented the differentiated use of habitat of a three-species turtle community in Mexico. Only recently have studies aimed to understand resource partitioning in turtle communities that include terrestrial turtles [ 21 , 22 ], but they did not estimate home range or compare microhabitat use and activity patterns among sympatric species.…”