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.

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.

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.

The hawksbill turtle (Eretmochelys imbricata) is critically endangered throughout its global range and is particularly threatened in the eastern Pacific, a region where our knowledge of the ecological traits is very limited. Understanding habitat preferences of hawksbills at different life stages is necessary to create effective local and regional conservation strategies. We studied habitat use and the diet of juvenile hawksbill sea turtles at Punta Coyote, a rocky reef located along the Nicoya Peninsula on the north Pacific coast of Costa Rica, along the northern boundary of the Caletas–Arío National Wildlife Refuge. We tracked 12 juvenile hawksbills (36–69-cm curved carapace length) with acoustic transmitters to study their habitat use. Turtles were on the rocky reef more frequently than the sandy bottoms (χ²₁  =  29.90, p  =  0.00). The 95% fixed kernel density home range analysis revealed high-intensity use of the rocky reef, where hawksbills mainly dove in shallow waters (7.6 ± 3.3 m). Less than 5% of the 95% home range area overlapped with the Caletas–Arío National Wildlife Refuge. Hawksbills fed mainly on 2 invertebrate species regardless of season: a sponge (Geodia sp.) (mean volume  =  67%) and a tunicate (Rhopalaea birkelandi) (mean volume  =  51%). Our surveys along the Nicoya Peninsula suggested that use of rocky reefs by juvenile hawksbill turtles was common. To protect juvenile hawksbills in the study area, we recommend that this site be granted official protection status as part of the Caletas–Arío National Wildlife Refuge. We also suggest studying other discrete rocky reefs along the Nicoya Peninsula to determine critical habitats for the hawksbill turtle to improve conservation and management policy.

Crypsis can be facilitated by dynamic color changes that are mediated by chromatophores of the integument. The histological bases of dynamic color changes are well understood for some reptiles, such as lizards, but less so for turtles. We used pixel counts from digital images of tail-tip sections to study histological changes that occur during substrate color-induced melanization, and reversal of melanization, in Midland painted turtles (Chrysemys picta marginata) during 2 companion studies. Melanization in C. picta marginata can be induced in light-skinned individuals when placed on a dark substrate and can be reversed in dark-skinned individuals when placed on a white substrate but without the shedding of scutes. Therefore, we predicted that color change would involve variations in intracellular melanosome concentrations within melanophores, in the deepest living epidermal cells, or both. At hatching, and in individuals that were reared on a white substrate, mean pixel density was relatively low in the stratum spinosum and corneum. In contrast, melanosome densities of the melanophore layer, stratum spinosum, and stratum corneum were relatively high in turtles that were reared on a black substrate. In a second experiment, mean pixel counts of the epidermal layers of turtles reared on a black substrate and then switched to a white substrate were relatively low when compared with turtles that were reared on a white substrate and then switched to a black substrate. Contrary to our expectations, melanosomes were deposited or degraded in both the living and nonliving cells of the epidermis.

Despite great advances in the understanding of marine turtle biology over the past 60 yrs, there is still a paucity of demographic data on the juvenile stage of their life history. These data are required to adequately predict population trends for these long-lived marine turtle species. In the early 1990s, juvenile green turtles (Chelonia mydas) were observed in the Trident Turning Basin at Port Canaveral, Brevard County, Florida. We began a study in 1993 to assess the species composition, size class distribution, and degree of residency of the marine turtles utilizing this man-made embayment as developmental habitat. The results of the first 18 yrs of that study are related here. Juvenile green turtles constituted 99.4% of the marine turtle captures. Straight carapace lengths (SCL) of turtles ranged from 20.0 to 52.0 cm with a mean of 31.7 cm, smaller than those observed in other known green turtle developmental habitats in Florida. The mean SCL of the green turtles in the basin has declined over the course of the study. Although initially there was a high recapture rate of turtles tagged in the basin, that rate declined significantly along with the size of the turtles at their most recent recapture and the interval of time between their first capture and most recent recapture. We attribute these declines to the increase in the number of juvenile green turtles recruiting to developmental habitats along Florida's east coast and to the limited forage available in the basin. Population surveys over the past 13 yrs of the study yielded estimates that ranged from 27 to 224 green turtles in the basin, with a mean estimate of 61 ± 10 turtles. The results of this study illustrate the value of long-term monitoring projects in understanding both juvenile green turtle habitat preferences and sea turtle population dynamics.

We tested the effectiveness of nest screens and habanero pepper powder as deterrents for reducing depredation of loggerhead sea turtle (Caretta caretta) nests on Sand Island, South Carolina, including nest-screening (1 × 1-m plastic or metal mesh secured over the nest; n  =  33), surface-treatment (15 ml of habanero pepper powder sprinkled on the surface of the sand; n  =  10), bottom-treatment (15 ml of habanero pepper powder sprinkled 3 cm above the top egg; n  =  10), and 10 control nests. Twenty-two of 66 nests were partially or completely depredated by coyotes (Canis latrans), and nest survival rates varied from a high of 80% for surface-treated, 75% for screened, 45% for bottom-treated, and 32% for control nests. We propose that early surface-treatment of nests with pepper powder may provide an effective and more efficient management alternative to using screens, which are more difficult and costly to install, for reducing nest depredation at sea turtle nests.

We examined the histology, histochemistry, and ultrastructure of Rathke's glands in hatchlings of the three-toed box turtle, Terrapene carolina triunguis, and the desert box turtle, Terrapene ornata luteola. Both species possess one pair (axillary) of Rathke's glands, which are similar anatomically and histochemically to one another. Each gland is composed of a single, highly vascularized secretory lobule, which is surrounded by a thick sheath of striated muscle. Two types of large secretory vacuoles characterize most of the holocrine cells produced by a relatively thin glandular secretory epithelium. Analysis of our results suggests that the chief secretory material of the smaller dark-staining type 1 secretory vacuole appears to be a glycoprotein complex. The larger, mostly translucent type 2 secretory vacuole contains multilayered and variously sized lamellar bodies, whose structural design is reminiscent of an epidermal lipid delivery system in vertebrates. The functional role of Rathke's glands in Terrapene and in other turtles remains unclear at the present time.

Urbanization of riparian corridors may alter or eliminate suitable freshwater turtle basking habitat due to fragmentation of shoreline vegetation, reduction of basking sites, or frequent human disturbance. We used 3 indices of shoreline urbanization at 2 spatial scales to assess the relationship between shoreline urbanization and basking turtle behavior. Indices included local-scale Shoreline Modification and Disturbance Frequency and broad-scale Building Density. The community of basking turtles included the Texas river cooter, Pseudemys texana (Baur); red-eared slider, Trachemys scripta elegans (Wied); Mississippi map turtle, Graptemys pseudogeographica kohnii (Baur); midland smooth softshell, Apalone mutica mutica (LeSueur); pallid spiny softshell, Apalone spinifera pallida (Webb); and a turtle from the family Kinosternidae that could not be identified to species during basking surveys. At the local scale, abundances of basking turtles were greatest in areas of high Shoreline Modification, characterized by a substantial reduction in woody shoreline vegetation. Disturbance Frequency of human intrusion limited turtle basking in areas with daily disturbance. At the broad scale, most turtles basked adjacent to shorelines with nearby buildings. All species of the turtle community basked in urban environments, but their tolerance of urbanization varied.

Loggerhead sea turtles Caretta caretta using an important shallow-water foraging ground at Drini Bay, Albania, were monitored over 3 consecutive summers (2008–2010). Working closely with local artisanal fishermen, researchers were able to obtain many of the sea turtles captured as bycatch (nontarget species). There were 407 new records (402 loggerhead and 5 green turtles, Chelonia mydas), with most (99%) being captured in 2 stavnike fish traps (a type of pound net) and a few with mrezh (gill nets). Morphometric data were collected from all captured turtles, and they were allocated into 10-cm size classes (length-frequency-distribution) based on their curved carapace length; caudal measurements were used to assess the developmental-stage of secondary sexual characteristics. An unusually high number of male loggerhead turtles (27%) were captured; their morphometric data were subsequently used as a reference for determining if short-tailed turtles might be adult or sexually developing females. Nesting has not been reported for Albania, so the presence of females is unclear. Drini Bay is also a developmental habitat, as 69% of the studied turtles were yet to mature. Interannual recaptures of 26 turtles allowed their incremental growth rate to be calculated.

The in-water status of green turtles (Chelonia mydas) in the northwestern Gulf of Mexico has received comparatively little attention in the management and conservation of this species in US waters. We addressed this void via entanglement netting surveys at 3 estuarine areas (Lavaca-Matagorda Bay, the Aransas Bay complex, and the lower Laguna Madre [LLM]) to assess trends in the relative abundance, distribution, and size composition of green turtles in Texas inshore waters during 1991–2010. Overall catch per unit effort (CPUE) in the LLM (1.5 turtles/km-hr) was significantly higher than that observed in the other 2 estuaries and corresponded to general climate patterns and seagrass areal coverage along the Texas coast. Yearly CPUE of green turtles from the LLM exhibited a significant exponential increase from 1991 to 2010, despite variability in capture rate during recent years. Mean straight carapace length (SCL) of green turtles was statistically similar across the 3 study areas and indicative of dominance by juvenile individuals (LLM mean  =  42.2 cm SCL). Historical green turtle size data in the LLM also reveal an overall decreasing trend in mean SCL and shift toward an increased percentage of smaller individuals (30–39.9- and 40–49.9-cm SCL size classes). Also, sighting frequency of postpelagic green turtles at the Brazos-Santiago Pass jetties within the LLM during 2009 was roughly 9 times that reported for comparable months during 1992–1993. These results are indicative of enhanced recruitment of neritic green turtles to the northwestern Gulf of Mexico, most likely due to elevated nesting productivity at beaches in Mexico, Florida, the Caribbean, and the western Atlantic. Overall, the lower Texas coast serves as an important developmental foraging habitat for an increasing population of juvenile green turtles in the northwestern Gulf of Mexico.

We scored 48 Malaclemys terrapin nests destroyed by raccoons on Fisherman Island, Virginia, for the presence or absence of tree canopy, shrub canopy, no canopy, bare sand, grass cover, and herbaceous cover. Significantly more nests than expected were found in the open with no vegetation cover and observed distances of predator-destroyed nests from the edge of the nearest habitat island of woody vegetation were significantly different from a normal distribution; most were placed near the island margin. Our results underscore the need to understand the influence of predator search behavior on terrapin nest survival in different habitat types.

We used informal conservation and focus group techniques to gather information in 2 Ashaninka communities in Pichis River valley, central Peru. We found that turtles were mainly used as food, although some medicinal and supernatural uses were also reported. Locals demonstrated a comprehensive knowledge on the underlying causes of contemporary reductions in turtle abundance within their territory; their spiritual beliefs, including taboos on catching turtles, and those relating to supernatural or sacred sites caused them to avoid hunting and fishing in some wetlands.

We radiotracked individuals of the exotic aquatic turtle Trachemys scripta elegans and 2 coexisting species of native turtles (Mauremys leprosa and Emys orbicularis) in southern Spain. Aquatic home range areas differed among species only in winter, when T. s. elegans moved in larger areas and showed shorter inactivity periods than the native turtles. Differences in these activity patterns may provide an advantage for individuals of the exotic species, which were already moving widely when native turtles started their posthibernation activity and would have been expected to be recolonizing their home ranges in depleted physical condition.

We report on a Euphrates softshell turtle (Rafetus euphraticus) nest and hatchlings that emerged from the nest that was constructed in a sand patch of the Dez River in southwestern Iran and discovered on 8 July 2012. Information on nest location and structure and hatchling morphology is presented.