Blanding's Turtle Nova Scotia population
Scientific Name: Emydoidea blandingii
Other/Previous Names: Emydoidea blandingi
Taxonomy Group: Reptiles
Range: Nova Scotia
Last COSEWIC Assessment: November 2016
Last COSEWIC Designation: Endangered
SARA Status: Schedule 1, Endangered
Image of Blanding's Turtle
Blanding’s Turtle is a medium-sized freshwater turtle, which is readily distinguished by its bright yellow throat and chin. Adults have a domed and smooth upper shell (carapace), which may be up to 27 cm in length. The carapace is generally black or dark brown, with some individuals exhibiting lighter shades of gray or brown. The carapace is marked with irregular yellowish or tan streaks and spots. The markings tend to get smaller and may fade altogether as the turtle ages. The lower shell (plastron) is a rich yellow colour and is hinged at the front. Because of this hinged plastron, some individuals can completely close their shell after retracting their head and feet into the shell. Males have a concave plastron, to facilitate mating, whereas the female’s plastron is flat. The sides of the long neck and top of the head are generally dark brown or black in males and lighter in colour or even mottled in females. The beak is notched on the upper jaw, and the mouth curves upward in what appears to be a permanent smile. Colours are generally brighter in younger individuals, but the spots and streaks that characterize the carapace of this species do not develop until after the second year. The hinge on the plastron is not functional in hatchlings and young juveniles, and in hatchlings and young juveniles the tail extends well beyond the edge of the carapace.
Distribution and Population
This northern species is found primarily in and around the southern Great Lakes region. Its range extends from the extreme southwestern edge of Quebec and southern Ontario to the west as far as central Nebraska and to the east to Ohio. In the United States, the range of Blanding’s Turtle in the northern states extends from Nebraska eastward to Ohio and Michigan and south to Missouri. Outside this main range, there are small isolated populations in New York, Massachusetts, New Hampshire and Maine. The Canadian population is divided into two geographically separate units, the Great Lakes/St. Lawrence population and the Nova Scotia population. These two populations are separated by several hundred kilometres. The small, isolated Nova Scotia population is at the extreme northeastern edge of the species’ range. It is restricted to two drainage basins in the centre of the southwestern portion of the province. At least three distinct sub-populations are recognized in Nova Scotia: one in Kejimkujik National Park of Canada and two others in working landscapes outside the park’s boundaries (McGowan Lake and Pleasant River). These three sub-populations are genetically distinct from each other and from other populations of Blanding’s Turtles. The Nova Scotia population has declined because of habitat alteration, collecting, mortality associated with roads, and other anthropogenic causes. A recent population viability analysis identified an alarming decrease in the Kejimkujik National Park population. This analysis, based on survivorship and reproductive data from the Nova Scotia population, has suggested that management actions are necessary to reverse the decline. In 2005, there were estimated to be only 210 to 245 adult Blanding’s Turtles remaining in Nova Scotia. Models based on demographic data from a long-term study of Blanding’s Turtle populations in Michigan indicate that population stability of such a long-lived, late-maturing species requires an annual survivorship of at least 76% for juveniles (ages 2 to 14 years) and adult survivorship of at least 96%. Blanding’s Turtles in Canada attain sexual maturity even later than in Michigan, so it is likely that Canadian populations require an even higher annual survivorship to maintain their numbers.
Blanding’s Turtle is largely aquatic. In summer, it is found in a variety of freshwater habitats, including lakes, permanent ponds, temporary ponds, slow-flowing brooks, marshes and swamps. An individual turtle may use several of these habitats, travelling more than 6760 m during a season. In general, Blanding’s Turtles prefer shallow, nutrient-rich waters with an organic substrate and dense vegetation. In Nova Scotia, this species is associated with darkly coloured acidic water and peaty soils. Adults are generally found in open or partially vegetated sites, whereas juveniles prefer sites that provide numerous refuges, i.e., thick aquatic vegetation, including sphagnum, water lilies and algae. Juveniles keep close to the water’s edge. The terrestrial habitat is also important, as these turtles travel long distances between aquatic areas to locate suitable basking and nesting sites. Despite these seasonal movements, Blanding’s Turtles exhibit strong site fidelity. The species generally nests in upland wooded areas consisting of mixed-wood forest up to 410 m from the nearest water source. Females also prefer nesting locations in relatively open areas, such as fields or roadways. Blanding’s Turtle nests in a variety of loose substrates, including sand, organic soil, gravel and cobblestone. Blanding’s Turtle overwinters under water, in permanent pools that average about 1 m in depth or in slow-flowing streams. In Nova Scotia, individuals tend to return to the same sites each year, where they overwinter in dense aggregations. Little is known about these overwintering sites.
In Canada, females reach sexual maturity fairly late, at the age of 25. Upon reaching maturity, adult females produce a maximum of one clutch per year (often only one clutch every two or three years). Each clutch has between 3 and 19 eggs (the average in Nova Scotia is 11). The eggs are laid in June, with hatchlings emerging in late September and early October. The cool Canadian climate results in a short active season, which limits nest success. Embryo development is dependent on incubation temperature; eggs incubated below 22°C or above 32°C will not develop properly. Since the minimum temperature for the successful development of Blanding’s Turtle embryos is relatively warm, the embryo mortality rate in the Canadian climate is high. The sex of Blanding’s Turtles is determined by the temperature of the eggs during incubation; eggs incubated at or below 28°C will produce males, while eggs incubated above 30°C will produce females. The Blanding’s Turtle is an exceptionally long-lived species and can survive in the wild in excess of 75 years.
Increased human activity (road building, cottage development and agriculture) has increased the fragmentation and degradation of the habitat of this small population. Similarly, changes in water flow regimes, primarily for power generation, are a particular concern as they may impede seasonal movements of Blanding’s Turtles and affect their ability to nest, to feed, and to reach overwintering sites. After habitat loss, nest predation by racoons, skunks, foxes and coyotes is one of the main causes of nest failure. There are few predators of mature turtles, as their carapace strength and overall size deter or prevent most predation. Cool summer temperatures may also increase the rate of nest failure. In such climatic conditions, those juveniles that do hatch fail to survive because a certain amount of heat is required for the eggs to develop fully. A recently discovered source of nest failure is parasitism by sarcophagid fly larvae. Development of wetlands and their surrounding terrestrial areas significantly reduces the amount of available and suitable habitat for Blanding’s Turtle and may result in nest destruction. In addition, development results in increased road traffic as well as the creation of new roadways. Individual Blanding’s Turtles travel long distances over land and they tend to travel along roadways; as a result, they are particularly susceptible to being struck and killed while crossing roads. Additionally, Blanding’s Turtles often nest on the gravel shoulders of roads. Females that nest beside a road are at risk while they are laying their eggs and the hatchlings are at risk when they emerge. Additionally, in Nova Scotia, many nests are laid on lakeshore cobblestone beaches, where they are susceptible to flooding during wet years. The pronounced yellow chin and throat of the Blanding’s Turtle contribute to its appeal. Unfortunately, this has made it a sought-after species in the pet trade. Individuals who collect species from the wild do not discriminate between age classes. Usually the adult females are removed from wild populations, as they are easier to locate. Removal of reproducing individuals from a population is a severe risk to the survival of a long-lived species. Removal of Blanding’s Turtles from the wild for the pet trade is a growing threat, but it is difficult to estimate the severity of this threat at this time. Finally, the high survivorship of adults, delayed sexual maturity, low reproductive output and concomitant low rate of recruitment of juveniles into the adult population each year make this species vulnerable to even tiny increases in the annual mortality of adults.
Federal ProtectionThe Blanding's Turtle, Nova Scotia population, is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
In Kejimkujik National Park of Canada the species is protected under the Canada National Parks Act. At the provincial level, the Blanding’s Turtle is protected under the Nova Scotia Endangered Species Act.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Blanding's Turtle (Nova Scotia population) in Canada
Status Final posting on SAR registry
Recovery Progress and Activities
Summary of Progress to date In Nova Scotia, Blanding’s Turtles are restricted to the south-western interior of the province where there are at least three small genetically distinct populations. In 2005, COSEWIC up-listed the Nova Scotia population of the Blanding's turtle from threatened to endangered, based partly on a population viability analysis that indicated at least one of these populations was declining. In 2000, Blanding's Turtles were declared endangered under the Nova Scotia Endangered Species Act. These decisions were based, in part, on the species’ limited distribution within the province, the population’s uneven age structure, and the low rate of recruitment into the breeding population. The Blanding’s Turtle Recovery Team has been in place since 1993 and there is a well-established research and stewardship program underway to protect turtles and their habitats, locate additional populations, and ascertain the true status and threats to the population. The goal of the Blanding’s Turtle recovery plan is to maintain and restore, where appropriate, the population size and structure through the maintenance and restoration of habitat and ecological processes. High adult survivorship is critical in this long-lived (70+ years) species. Summary of Research/Monitoring Activities Researchers have been individually marking Blanding’s Turtles in Kejimkujik National Park and National Historic Site (KNPNHS) since 1969 and monitoring their nesting activity annually since 1992. Research on populations outside the Park began in 1996 and has increased in recent years. The primarily student-driven research team has investigated various aspects of the turtle’s biology including population genetic structure, overall range in Nova Scotia, nesting behaviour and nest success, hatchling movements, over-wintering ecology, juvenile growth, habitat characteristics, age-relate survivorship, and population trends. Researchers have been conducting studies on genetic variation throughout the North American range since 1995. Research has shown that the Nova Scotia population has significantly diverged genetically from populations in the main range and harbours a significant portion of the total genetic biodiversity of the species. Within Nova Scotia, the three known populations are genetically distinguishable suggesting that there is very little movement of turtles between them. Differences in behaviour, habitat use, growth rates, adult size, and clutch size also have been recorded among them. Summary of Recovery Activities Of the three known populations of Blanding’s Turtle in Nova Scotia, one occurs in a National Park, one primarily in a combined provincially and privately protected area, and one in a working landscape dominated by small private landholdings. This diversity presents an array of conservation and management opportunities. Recovery activities in working landscapes have incorporated research and public education and outreach, allowing science and stewardship to converge. Recovery activities to date have involved collaborations with government, industry, local organizations, and community members. A volunteer-based nest protection program was established in KNPNHS in the 1990’s and has since expanded to the two known populations outside the Park. Each night during nesting season, volunteers and researchers monitor known nesting sites and observe females as they go through the nesting process. Once a turtle nest is complete, a wire-mesh cage is placed over the nest to protect it from predators. In recent years, over 1000 hours of volunteer effort each year has helped protect more than 30 nests annually. This program is continuing to expand to provide local community members, and other volunteers, opportunities to be directly involved with many aspects of recovery. Since 2002, researchers have been captivity rearing hatchlings in an area where we know the population has declined over the past 40 years in an attempt to boost the population size. Hatchlings are raised in captivity for the first 1 or 2 years of life and then released back into the population when they have reached a large enough size to reduce their risk of predation. Because Blanding’s Turtles are slow to mature (20+ years), there is a long lag between the time researchers initiate recovery actions, such as protecting nests or rearing hatchlings, and the time new adults begin to appear in the breeding population as a result of these actions. URLs Nova Scotia’s Blanding’s Turtles Conservation and Recovery:http://www.speciesatrisk.ca/blandings/
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
11 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- COSEWIC Assessments (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Action Plans (1 record(s) found.)
- Orders (3 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Critical Habitat Descriptions in the Canada Gazette (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2005 (2005)2005 Annual Report to the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
Critical Habitat Descriptions in the Canada Gazette
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