Blanding's turtle is a North American freshwater turtle whose main range occurs south of the Great Lakes; disjunct populations occur east of the Appalachian Mountains from New York to Nova Scotia. The species is listed as threatened or endangered in most of its range. We employed five variable microsatellites to examine samples of 300 individuals in 12 populations. Estimates of F ST based on pairwise comparisons of populations ranged from 0.000 to 0.465. Phylogenetic analysis of these F ST values reveals that the Appalachian Mountains and the Hudson River appear to present major barriers to gene flow in Blanding's turtle. The extent of fine-scale genetic structure previously reported in the Nova Scotian populations was not found in other parts of the species' range. We recommend that populations separated by the Appalachian Mountains as well as the highly disjunct Nova Scotian populations of Blanding's turtle be recognized as evolutionarily significant units.

This study was conducted to obtain accurate information on the reproductive ecology of the threatened population of Blanding's turtle (Emydoidea blandingii) in Nova Scotia. In 1994, 1995, and 1996, beaches and roadways in Kejimkujik National Park were surveyed for nesting turtles; all nests observed were covered with wire-screen cages to prevent predation and facilitate the collection of data on incubation and nest success. Nesting lasted from mid-June until early July. In each year, 80% of nesting occurred during a 10-day period in the third and fourth weeks of June. Turtles nested in the evening and predominantly on lakeshore cobble beaches. Site fidelity is high in this population: 73.3% of multiparous females returned to nest on the same beach in all years. No female produced more than one clutch per season, and most females (67.9%) nested less than annually. Mean clutch size was 10.6 eggs. Hatchlings emerge in September and October. Incubation times ranged from 80 to 128 days (mean = 94 days, SD = 11.7 days; n = 26 nests). In 1994 and 1995, most protected nests were productive; that is, 76.4 and 93.3% of protected nests produced at least one live hatchling in 1994 and 1995, respectively. In 1996, only 18.1% of protected nests were productive. Between 50 and 75% of productive clutches contained unhatched eggs and, on average, between 1.0 and 1.2 eggs failed per productive clutch. Total annual egg failure ranged from 26.5 to 94%. In the absence of nest predation, lower temperatures during incubation and nest flooding appear to be major cause of egg failure in this population. More effective means of reducing nest failure and bolstering recruitment must be implemented if efforts to aid the recovery of this threatened population of Blanding's turtle are to be successful.

No abstract

No abstract

In Canada and the United States, the Blanding's turtle, Emydoidea blandingii (Family Emydidae), is officially designated as endangered or threatened in several provinces and a number of states. In many areas, it has become a "poster species" for attracting public interest in issues common to conservation of freshwater turtles in general. Over the past three decades, knowledge of Blanding's turtle biology and ecology has increased dramatically, and among species with conservation concerns, it now ranks as one of the best known turtle species throughout much of its range. Blanding's turtles seldom occur in dense populations such as those of sympatric painted turtles, but two large populations exist in southeastern Minnesota, and in north-central Nebraska. Individuals delay maturity from 14-21 yrs, and can attain ages greater than 75 yrs and still reproduce successfully. Most populations of Blanding's turtles are threatened by collecting, road mortality, and the reduction and degradation of both aquatic and terrestrial portions of their core habitats. Adults of both sexes make extensive forays onto land to visit temporary wetlands, and adult females move overland on pre-nesting movements and to nest; both activities exposes adults to increased risk of mortality associated with roads, farm machinery, and terrestrial predators. Proposed conservation measures include: 1) methods to reduce road mortality (e.g., fencing and road passages); 2) elimination of commercial collecting; 3) protection of large resident wetlands and smaller ephemeral wetlands; 4) protection and management of adjacent terrestrial areas used for nesting and as corridors for movements among wetlands; 5) research on risks associated with the timing and duration of terrestrial movements of both sexes; and 6) where necessary, removal of nest predators. More extensive regional information can be found in Herman et al. (2003), COSEWIC (2005), and Congdon and Keinath (2006). DistriBution.-Canada, USA. Distributed disjunctly from southeastern Ontario, adjacent Quebec, and southern Nova Scotia, south into New England, and west through the Great Lakes to western Nebraska, Iowa, and extreme northeastern Missouri. synonymy.-Testudo flava Lacépède 1788 (name suppressed), Testudo meleagris Shaw 1793 (name suppressed), Lutremys meleagris, Emys meleagris, Cistuda blandingii Holbrook 1838, Cistudo blandingii, Emys blandingii, Emydoidea blandingii, Neoemys blandingii, Emys twentei Taylor 1943. suBsPeCies.-None recognized, but three separate evolutionarily significant units have been identified: 1) the main populations west of the Appalachian Mountains, 2) the disjunct populations east of the Appalachians in southern New York and New England, and 3) the highly disjunct eastern population in southern Nova Scotia. status.-IUCN 2007 Red List: Near Threatened (LR/nt) (assessed 1996, needs updating); CITES: Not Listed; US ESA: Category 2 (Candidate for Listing); Canada Species at Risk Act: Endangered (Nova Scotia), Threatened (Great Lakes / St. Lawrence). Taxonomy.-The Bl...