Species‐Specific Genetic Patterns in Sympatric Freshwater Turtles Challenge a Generalized Multi‐Species Conservation Approach

We used radio-telemetry to investigate the seasonal dynamics of wetland use by Spotted Turtles (Clemmys guttata) and Blanding's Turtles (Emydoidea blandingii) in southern Maine. Habitat use was examined in a temporally segregated manner, comparing wetland use among seasonally discrete activity periods. Distinct seasonal movement patterns were detected and logistic regression revealed significant differences in wetland characteristics across seasons for both species. Spotted Turtles exhibited a positive association with wetlands hosting abundant Wood Frog (Lithobates sylvaticus) egg masses in spring, and a negative association with forested wetlands from spring through late summer. Blanding's Turtles were closely associated with forested wetlands in spring, wetlands with abundant Wood Frog egg masses and good sun exposure in early summer, and deep-water wetlands in late summer and fall. The seasonal differences in habitat use found in this study highlight the complex and dynamic landscape required to sustain these rare turtles. Spotted and Blanding's Turtles' diverse habitat requirements require frequent terrestrial movements, exposing them to threats for which mitigation requires understanding spatial and temporal shifts in habitats use.

Lipid provisioning of turtle eggs and hatchlings: total lipid, phospholipid, triacylglycerol and triacylglycerol fatty acids

One of the deadliest roads in North America for species at risk fragments a marsh‐lake ecosystem. To reduce road mortality, stakeholders installed >5 km of exclusion fencing along a southwestern Ontario, Canada, causeway in 2008–2009. Between 2012 and 2014, 7 culverts were installed to provide safe crossings. We evaluated the success of these mitigation strategies by 1) comparing results of road surveys conducted 5 years before and 5 years after fencing installation; and 2) monitoring use of culverts by turtles using motion‐activated cameras at culvert openings and stationary antennas placed to detect movements of passive integrated transponder (PIT)‐tagged turtles (68 Blanding's turtles [ Emydoidea blandingii ] and 30 spotted turtles [ Clemmys guttata ]). We also radio‐tracked 30 Blanding's turtles to measure culvert use in relation to home ranges. Turtle and snake abundance was 89% and 53% lower, respectively, in completely fenced road sections than in unfenced sections; abundance was 6% and 10% higher, respectively, between partially fenced and unfenced sections. After mitigation, locations where we found reptiles on the road were associated with fence ends, underscoring the importance of fence integrity and ineffectiveness of partial fencing as a mitigation strategy. We confirmed use of culverts by Blanding's turtles, northern map turtles ( Graptemys geographica ), snapping turtles ( Chelydra serpentina ), and midland painted turtles ( Chrysemys picta ). Through radio‐tracking, we determined that male and female Blanding's turtles home ranges overlapped with different segments of the causeway. We recommend that stakeholders emphasize ensuring fence integrity and continuity, limiting impact of edge effects, and conducting a comprehensive monitoring program. © 2017 The Wildlife Society.

We report the season of emergence from the nest of hatchlings of five species of freshwater turtles from a wetlands/stream/lake complex in southcentral New Hampshire from 1988–1994. Only hatchling Chrysemys picta (Painted Turtle) overwintered in the nest and emerged the following spring, although there were some cases of autumn emergence, as well as some nests with hatchlings that emerged in both seasons. In nests monitored over the winter, mortality ranged from 26–100%. Hatchlings of the other four species—Chelydra serpentina (Snapping Turtle), Glyptemys insculpta (Wood Turtle), Clemmys guttata (Spotted Turtle), and Emydoidea blandingii (Blanding's Turtle)—emerged only in autumn.

The distribution of Ohio reptiles was worked out by Conant (1938), and the host names used below are those given by him. Ten species of turtles have been recorded from Ohio. Of these, the Cumberland terrapin, Pseudemys scripta troostii (Holbrook), and the brown soft-shelled turtle, Amyda mutica (Le Sueur), are rare, and local in distribution. In addition to these, we were unable to obtain specimens of the musk turtle, Sternotherus odoratus (Latreille), which, while not common, is rather widely distributed over the State. The seven species of turtles examined were as follows: spiny soft-shelled turtle, Amyda spinifera (Le Sueur); snapping turtle, Chelydra serpentina, (Linne); painted turtle, Chrysemys bellii marginata Agassiz; spotted turtle, Clemmys guttata (Schneider); Blanding's turtle, Emys blandingii (Holbrook); geographic terrapin, Graptemys geographica Le Sueur; and the land turtle Terrapene carolina (Linne). The number of host specimens examined of certain species is not adequate, but since there is no probability that additional specimens will be obtained from this area, the data are presented with these inadequacies. A summary of the results is shown in table 1. While we realize that our material cannot be considered sufficient in amount to allow for an ecological study, it seems desirable, nevertheless, to present short descriptions of the major habitats from which the animals were collected. This may be of value to someone doing work of a similar nature in the future. It is hoped that future workers will attempt to correlate distribution of the parasite with the ecology of the host, since little is known of the epidemiology of the helminths parasitic in wildlife. The locations from which collections were made are indicated by number on the map (Fig. 1.), and descriptions of these habitats are given below.

Abstract: We investigated the habitat use and movements of two turtle species to assess the importance of conserving multiple wetlands and the upland matrix in which they occur. Spotted turtles ( Clemmys guttata ) and Blanding's turtles ( Emydoidea blandingii ) are considered threatened and endangered, respectively, in Maine where they are near the northeastern periphery of their geographic range. We used resightings of marked individuals (69 spotted, 16 Blanding's) and radiotelemetry (13 spotted, 9 Blanding's, radiotagged for one or two seasons) to investigate the movements and habitat use of both species. Individuals of both species used multiple wetlands throughout the year, including permanent and seasonal pools, forested swamps, and wet meadows. Pools occupied by spotted and Blanding's turtles were small (<0.4 ha), and they were less isolated from other wetlands than pools that did not contain turtles. Both species used uplands extensively for nesting, dormancy, and traveling between wetlands. Turtles traveled 70–570 m (spotted) and 100–1620 m ( Blanding's) to nest, and nests were located 1–120 m (spotted) and 70–410 m ( Blanding's) from the nearest wetland. Spotted and Blanding's turtles entered relatively dormant stages for 15–89 and 3–21 consecutive days, respectively, and upland dormancy sites were 12–80 m (spotted) and 30–110 m ( Blanding's) from the nearest wetland. Total distance traveled overland throughout a season was 0–1680 m and 0–6760 m for radiotagged spotted and Blanding's turtles, respectively. Most spotted turtles followed a seasonal pattern of habitat use: pools for spring activity, upland forest for relative dormancy during part of the summer, and wet meadows or forested swamps for overwintering. A seasonal pattern in the habitat use of Blanding's turtles was not as evident. Our study suggests that protecting small wetlands, maintaining generous terrestrial buffers around individual wetlands, and conserving wetlands in groups are important components of a landscape approach to species conservation.

Overwintering habits of hatchling Blanding's turtles (Emydoidea blandingii) are unknown. To determine whether these turtles are able to survive winter in aquatic habitats, we submerged hatchlings in normoxic (155 mmHg Po2) and hypoxic (6 mmHg Po2) water at 4 degrees C, recording survival times and measuring changes in key physiological variables. For comparison, we simultaneously studied hatchling softshell (Apalone spinifera) and snapping (Chelydra serpentina) turtles, which are known to overwinter in aquatic habitats. In normoxic water, C. serpentina and A. spinifera survived to the termination of the experiment (76 and 77 d, respectively). Approximately one-third of the E. blandingii died during 75 d of normoxic submergence, but the cause of mortality was unclear. In hypoxic water, average survival times were 6 d for A. spinifera, 13 d for E. blandingii, and 19 d for C. serpentina. Mortality during hypoxic submergence was probably caused by metabolic acidosis, which resulted from accumulated lactate. Unlike the case with adult turtles, our hatchlings did not increase plasma calcium and magnesium, nor did they sequester lactate within the shell. Our results suggest that hatchling E. blandingii are not particularly well suited to hibernation in hypoxic aquatic habitats.

Nineteen Blanding's turtles (Emydoidea blandingii), eight snapping turtles (Chelydra serpentina) and fourteen painted (Chrysemys picta) turtles trapped in Nova Scotia in 2005 were examined for epizoic algae. Algae were macroscopically apparent on 14 Blanding's and seven snapping turtles; microscopic examination of material scraped fiom various surfaces of these turtles revealed the predominance of two algal taxa. The cladophoroid green alga Basicladia chelonum was common on the shell of both Blandiig's and snapping turtles and also present on the head and tail of the latter. B. chelomun is reported for the first time in Canada east of Ontario. A filamentous cyanobacterium, Komvophoron sp., formed extensive colonies solely in the leg bases of Blanding's turtles, where B. chelonum was absent. Although the nature of the interaction is unknown, this is the first potential symbiosis between a cyanobacterium and a turtle. Examination of a historical (2001–05) photographic database for Blanding's turtle in Nova Scotia revealed a colonization rate of 10% for B. chelonum and 46% for Komvophoron sp. It also revealed population and age-specific differences in frequency of the two algal taxa on Blanding's turtles.

The order Onygenales contains multiple fungal pathogens that affect free-ranging and zoo-housed reptilian species. Emydomyces testavorans, an onygenalean fungus associated with skin and shell disease, has been sporadically detected in aquatic chelonians. Because of the recent discovery of this organism, little is known about its prevalence in free-ranging chelonians. The objective of this study was to perform surveillance for E. testavorans in six free-ranging aquatic and terrestrial chelonian species in Illinois, USA: Blanding's turtles (n=437; Emydoidea blandingii), painted turtles (n=199; Chrysemys picta), common snapping turtles (n=35; Chelydra serpentina), red-eared sliders (n=62; RES; Trachemys scripta elegans), eastern box turtles (n=73; Terrapene carolina carolina) and ornate box turtles (n=29; Terrapene ornata). Combined cloacal-oral swabs (COSs) or shell (carapace and plastron surfaces) swabs were collected from 2019 to 2021 and tested for E. testavorans using quantitative PCR. The PCR detected E. testavorans in COSs of an adult male, subadult female, and juvenile male Blanding's turtle (0.6%; 95% confidence interval [CI], 0.2-1.9%) and a shell swab from an adult female RES (1.6%; 95% CI, 0-8.7%). Shell lesions consistent with E. testavorans infection were present in two of the positive Blanding's turtles. These results document the rarity of this pathogen on the landscape in Illinois. Additional studies should determine this pathogen's impact on individuals and clarify its significance for conservation efforts of Blanding's turtle, in which E. testavorans has not been reported previously.

Diel activity patterns in animals can be diurnal (concentrated during daylight), nocturnal (concentrated during darkness), cathemeral (both daylight and darkness) or crepuscular (concentrated at twilight). Freshwater, Nearctic turtles are typically considered diurnal, apart from crepuscular or nocturnal nesting migrations by mature females. However, some crepuscular and nocturnal activity has been observed in non‐nesting freshwater turtles. There are no quantitative studies of nocturnal movements in freshwater turtles, but GPS‐tracking devices provide an opportunity to collect and archive locations for 24 h, providing the GPS antenna is exposed above water. We collected GPS locations and shell temperatures from mature spotted turtles (Clemmys guttata, n = 12) and Blanding's turtles (Emydoidea blandingii, n = 12) from May to July 2018 in southern Ontario, Canada. We compared the minimum distance moved by turtles during the day and night, and we tested previously proposed hypotheses that nocturnal movement is linked to nesting or thermoregulatory benefits. Blanding's turtle movements were primarily diurnal, but spotted turtles were cathemeral. Nocturnal activity by spotted turtles was not restricted to the nesting season and did not confer thermoregulatory benefits. We hypothesize that nocturnal exposure and movement by spotted turtles provide increased time for foraging or mate‐seeking, allowing daytime hours to be used for basking. Our study demonstrates cathemeral diel patterns in spotted turtles and quantitatively tests hypotheses about the drivers of nocturnal behaviour in freshwater turtles. Future research should use observational methods in order to better understand the purpose of nocturnal activity in Nearctic, freshwater turtles.

AimChanges in both land use and climate can cause population declines and species extinctions, but the relative effects of these two stressors are often dependent on species‐specific life histories. Turtles are highly threatened as a taxonomic group and are particularly sensitive to environmental change due to their life history, habitat preferences and physiology. We used both sex data and genetic diversity across a landscape‐scale gradient in land use intensity and recent climate change to characterize the relative effects of these factors on three turtle species (including the endangered Blanding's turtle, Emydoidea blandingii) with different life histories and thus different vulnerabilities to environmental change.LocationWisconsin, USA.MethodsTurtles were captured and sampled for genetic analyses at 18 sites. Sampled individuals were genotyped for species‐specific sets of microsatellite markers, and population‐level genetic diversity was assessed using rarefied allelic richness and heterozygosity. The relative effects of road density, public land area and recent climate change on genetic diversity and sex ratio were evaluated using regression methods and model‐selection criteria.ResultsIncreased land use intensity was associated with male‐skewed sex ratios and decreased genetic diversity in E. blandingii but not co‐occurring species. Recent climate change did not explain variability in either sex ratio or genetic diversity for any of the three species examined.Main conclusionsChanging land use has multiple impacts on turtle populations that are modulated by species‐specific life history traits. Extensive terrestrial movements associated with nesting in E. blandingii increase female vulnerability to road mortality, which in turn has led to declines in genetic diversity. The predicted effects of recent climate change may have been dampened by behavioural plasticity. We suggest that the disproportionate effect of land use on E. blandingii warrants greater legal protection for this species.

Freshwater turtle hatchlings primarily use visual cues for orientation while dispersing from nests; however, hatchlings rapidly develop a relationship between a sun or geomagnetic compass and a dispersal target that allows them to maintain an established direction of movement when target habitats are not visible. We examined dispersal patterns of hatchling snapping turtles (Chelydra serpentina) and Blanding's turtles (Emydoidea blandingii) dispersing in large arenas in a mowed field and in dense corn. The dispersal of three categories of hatchlings were examined: (1) naïve individuals (no previous dispersal experience), (2) arena‐experienced (limited dispersal experience in arenas in natural habitat), and (3) natural‐experienced hatchling Blanding's turtles (captured after extensive experience dispersing W in natural habitats toward wetlands). Experienced hatchlings were assigned to treatments consisting of having a magnet or a non‐magnetic aluminum sham or nothing glued to their anterior carapace before release in the corn arena. Dispersal patterns of naïve hatchlings of both species were strongly directional in the field arena with visible target horizons and primarily random in the corn arena where typical target horizons were blocked. When released in corn, dispersal patterns were similar for arena‐experienced hatchlings with magnets or shams attached and differed from their prior dispersal headings in the field arena as naïve hatchlings. Natural‐experienced hatchling Blanding's turtles with and without magnets were able to accurately maintain their prior headings to the WNW while dispersing in the field or corn arenas (i.e., the presence of a magnet did not disrupt their ability to maintain their prior heading). Based on the assumption that no other type of compass exists in hatchlings, we conclude that they were not using a geomagnetic compass, but by default were using sun compass orientation to maintain dispersal headings in dense corn where no typical target habitats were visible.

Multi‐species approaches provide valuable insight for conservation planning, yet most studies focus on only one species while generalizing across taxa. Here, we employed 5–14 microsatellite DNA loci to evaluate population genetic patterns and future vulnerability for a freshwater turtle assemblage distributed across north‐eastern Illinois. Focal species (Emydoidea blandingii, Clemmys guttata, Chrysemys picta and Chelydra serpentina) differ in conservation status as well as in ecological and life‐history traits, which modulate gene flow across heterogeneous landscapes. We hypothesized (1) common and more ubiquitous species (C. picta and C. serpentina) would exhibit higher levels of genetic connectivity compared to species more restricted in distributions and with an elevated conservation status (E. blandingii and C. guttata) and (2) endangered species exhibit a greater loss of future genetic diversity. We found that genetic patterns varied considerably among co‐distributed species. Endangered species had lower levels of genetic diversity and gene flow, more pronounced genetic structure and a higher risk of genetic drift compared to common species, thus supporting our hypotheses. The observed patterns are potentially attributable to life‐history and ecological traits and will affect the long‐term viability of the four species within a modified north‐eastern Illinois landscape. Our study is an important first step for understanding how landscape features and species‐specific traits interact to affect gene flow and population genetic structure within altered landscapes. It also underscores how multi‐species approaches can be informative for conservation actions.

Tropical reef fishes exhibit a large disparity of organismal morphologies contributing to their astonishing biodiversity. Morphological disparity, scaling from differences among individuals within populations to differences among species, is governed by ecological and evolutionary processes. Here, we examined the relationship between intra- and interspecific disparity in 1111 individuals from 17 tropical reef fish species, representing 10 families with different dispersal abilities, across four Indian Ocean regions. We compared intraspecific measurements with species-level measures from a database of 1061 reef fish species. Species with high morphological disparity among individuals from distinct regions are found to be nested in families that display a high disparity among their genera. We show an association between the morphological disparity at the intra- and interspecific levels for several morphological ratios such as the caudal peduncle elongation. We evaluated the link between morphological disparity and genetic diversity with species dispersal ability. A structural equation model indicates that dispersal ability correlates positively with species genetic diversity, which is associated with morphological disparity. Our results suggest that traits associated with dispersal may foster gene flow and morphological evolution. Future works combining genomic, morphological and environmental data across more species is necessary to generalize these findings to other regions.

Dispersal ability of island endemic plants: What can we learn using multiple dispersal traits?