Abstract

Historic commercial collecting of the alligator snapping turtle (Macrochelys temminckii) appears to have severely reduced populations throughout much of its range. In this study, we analyze 8 seasons of turtle-trapping data from 11 major rivers in southern Alabama and provide the first report on the status of the species in the state. During 1332 trap nights, we captured 93 M. temminckii in 7 rivers in south Alabama. We recorded relatively low overall catch per unit effort (CPUE; 0.062 using paired hoop nets connected by a lead net, 0.081 using single-baited hoop nets) compared with recent studies from other states. By evaluating relative abundances, size distributions, and sex ratios, we document variation in abundance among independent river populations as well as unexpected sex ratios. In particular, the Fowl River population is characterized by unexpectedly high abundance (0.478 CPUE) and may represent historic population conditions prior to commercial trapping. We discuss distribution and abundances, conservation concerns, and the significance of the Fowl River with respect to the recovery of populations throughout the species' range. This study contributes baseline population data to better understand the ecology and conservation of M. temminckii both in Alabama and across its entire range.

Abstract

Optimal egg size theory predicts that natural selection optimizes egg size within populations and most of the variation in reproductive output is attributable to clutch size variation driven by body size, available resources, and age. For small-bodied turtles, morphological (pelvic) constraint on egg size has been considered the main explanation when populations exhibit considerable variation in egg size, because the pelvis could be under selection for other functions besides reproduction. Kinosternids, a small-bodied and semiterrestrial lineage of turtles, show evidence for both pelvic and nonpelvic constraint on egg size. In order to test if small species show a tendency toward pelvic constraint on egg size, we examined possible pelvic constraints in 1 population of the small-bodied Kinosternon chimalhuaca from western Mexico and in 3 populations of medium- to large-bodied Kinosternon integrum from central Mexico. Gravid females were X-rayed to measure both pelvic aperture and egg width. To test for pelvic constraint on each population we compared the slopes of pelvic aperture and egg width (mean and maximum) to body size (plastron length) with analysis of covariance (ANCOVA); we also compared egg elongation with fresh egg measurements among populations using ANCOVA (with body size as covariate), and we conducted an allometric analysis in order to test for egg size optimization. We found evidence of pelvic constraint in 1 population of K. integrum, and evidence of nonpelvic constraint in the K. chimalhuaca population and in the other 2 populations of K. integrum. Our data did not support the supposed adaptive compromise and pelvic constraints on egg size in small-bodied turtles reported in other studies. Environmental factors such local pressure on egg size (stability of the environment) could explain this pelvic constraint discrepancy in kinosternids.

Abstract

Nest-site selection can influence both the survivorship of a clutch of eggs as well as the phenotype of resulting hatchlings. The purpose of this study was to determine whether nest sites of Gopherus polyphemus in southern Mississippi differed from randomly chosen prospective nest sites with respect to various habitat parameters. Data were collected that described habitat variables we thought could be biologically relevant. Univariate tests were used to both compare nest sites with non–nest sites, as well as to further narrow the list of variables into those included in an analysis with Akaike's Information Criterion (AIC). Our AIC analysis suggests that the amount of bare soil at the apron and the composition of the soil are important factors when modeling nest-site selection for this tortoise. Aprons with nests contained more bare soil (less vegetation and litter cover) and less clay content in the soil than did randomly chosen aprons that did not have nests. These results indicate that nest sites of G. polyphemus in southern Mississippi differ from random, potential nest sites, implying that females exhibit nest-site selection.

A boy had stopped his car

To save a turtle in the road;

I was not far

Behind, and slowed,

And stopped to watch as he began

To shoo it off into the undergrowth—

This wild reminder of an ancient past,

Lumbering to some Late Triassic bog,

Till it was just a rustle in the grass,

Till it was gone.

I hope I told him with a look

As I passed by,

How I was glad he’d stopped me there,

And what I felt for both

Of them, something I took

To be a kind of love,

And of a

Stranding and Outcome Data for Cold-Stunned Sea Turtles in Massachusetts, 2008–2022: Evolution of Management Methods in Response to Increasing Caseload and the COVID-19 Pandemic

Charles J. Innis,

Kate Sampson,

Alessia Brugnara,

Sean Perry,

Karen Dourdeville,

Robert Prescott,

Constance Merigo,

Deana Edmunds,

Kathryn A. Tuxbury,

Linda Lory,

Kerry McNally,

Julie M. Cavin,

Melissa Joblon,

Jessica Ciarcia,

Michaela Wellman,

Katie Pugliares Bonner,

Julika Wocial,

Sarah Perez,

Sarah Dicarlo,

Kristen Luise,

Kurt Hood,

Nicole Hunter,

Jennifer Kiesling,

Elizabeth Linske,

Erin Mangan Sullivan,

Marisa Tardiani,

Eric Payne,

Katie Yungman,

Tina Wilkins,

Christine Sinnigen,

Aubrey Sperry,

Mary Beth Tims,

Nina Nahvi,

Alyssa Kaufold,

Nina Fischer,

Abigail S. Holding, and

Adam Kennedy