Five-lined skink (Eumeces fasciatus) COSEWIC assessment and status report: chapter 2

• Previous page
• Table of contents
• Next page

Executive Summary

Species information

Eastern Canada’s only lizard, Eumeces fasciatus, is a secretive, small-bodied animal that reaches a maximum size of approximately 86 mm snout-vent length. Juveniles have five cream-coloured stripes on their black bodies and prominently display the species’ most characteristic feature, a bright blue tail. Body colouration fades with age in both sexes, although females retain more of the original colour pattern. In the breeding season, males develop orange colouration around the jaws and chin. The scales are unkeeled, giving the animal a smooth, shiny appearance.

Distribution

The geographic range of E. fasciatus roughly coincides with the deciduous hardwood forests of eastern North America, making it the most widely distributed lizard in eastern North America. The species’ range extends from the Atlantic seaboard west to Texas and Minnesota and from southern Ontario south to the Gulf of Mexico. In Canada, the species is restricted to two disjunct series of populations in Ontario: 1. the Great Lakes/ St. Lawrence populations which occur on the southern Canadian Shield (from Georgian Bay east to the St. Lawrence River); and 2. the Carolinian populations which occur in Southwestern Ontario (near the shores of Lakes Erie, St. Clair, and Huron).

Habitat

The species’ habitat varies throughout its range and includes rocky outcrops, sand dunes, and open deciduous forests. It primarily inhabits early successional habitat with low to moderate canopy cover. Individuals spend the majority of their time under rocks, woody debris and other forms of cover; thus suitable microhabitats are of great importance to the species. The two series of populations in Ontario occur in distinct habitats, within which individuals use specific cover elements for refuge. Great Lakes/ St. Lawrence populations occur on the Canadian Shield on rock outcrops embedded in a matrix of coniferous and deciduous forest, and individuals in these populations seek refuge under rocks overlaid on open bedrock. Carolinian populations occur in Carolinian forest with a sandy substrate, and individuals within these populations have a strong association with woody debris as refuge.

Biology

In Ontario, the active season of E. fasciatus is from mid-April to late September or early October. Individuals are sexually mature after they emerge from their second hibernation, at 21 months of age. Several weeks after mating, the female locates a suitable nest site, excavates a nest cavity and lays a clutch of approximately 9 eggs, which she will brood and defend. Females often nest communally. Eumeces fasciatus is an active forager and consumes mainly invertebrates. Predators of the species include snakes, small mammals and predatory birds. Skinks will often autotomize their tails to escape predators. Although males are aggressive toward each other during the breeding season, the species is not territorial and individuals do not have strictly defined home range boundaries.

Population sizes and trends

Approximately 84 populations have been reported on the Shield within the last decade, while only five Carolinian populations have been confirmed in this same period. Carolinian populations have been declining and disappearing since at least 1984. Data on population trends exist for only one Carolinian Population. As a result of microhabitat destruction and removal, this population suffered a three-fold to five-fold decline in numbers from 1990-1995. Population density varies greatly throughout the year, and cohort structure can vary among years depending on weather conditions and other factors. Any particular adult cohort can be reduced by at least half within a year for a variety of reasons.

Limiting factors and threats

Eumeces fasciatus has a strong association with particular microhabitat elements that provide refuge. Destruction or removal of this microhabitat (e.g. cover rock or woody debris) can cause a decline in population abundance. Illegal collecting has been documented in at least one Carolinian Population, and is likely facilitated by the social nesting behaviour displayed by females. Alteration of microhabitat and illegal collecting have been identified as threats to Carolinian populations; the impact of these threats to populations on the Shield is less clear. Other threats include dogs, cats and high numbers of raccoons (Procyon lotor) and road mortality.

Special significance of the species

Eumeces fasciatus is eastern Canada’s only lizard, and occurs exclusively within two distinct habitat types. The skink is a charismatic animal that may inspire the public to elevate their appreciation of Canadian reptiles.

Existing protection

Although listed as Secure in most of its southern U.S. jurisdictions, several northern jurisdictions consider the species to be imperiled or extirpated. The species has been assessed as Special Concern by COSEWIC in 1998; it is also listed as Special Concern by the Ontario Ministry of Natural Resources.

COSEWIC History

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list.  On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC Mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC Membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

Definitions

Wildlife Species

A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.

Extinct (X)

A wildlife species that no longer exists.

Extirpated (XT)

A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.

Endangered (E)

A wildlife species facing imminent extirpation or extinction.

Threatened (T)

A wildlife species likely to become endangered if limiting factors are not reversed.

Special Concern (SC) ^Footnotea

A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.

Not at Risk (NAR) ^Footnoteb

A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.

Data Deficient (DD) ^{Footnote c}

A category that applies when the available information is insufficient (a) to resolve a species' eligibility for assessment or (b) to permit an assessment of the species' risk of extinction.

Canadian Wildlife Service

The Canadian Wildlife Service, Environment Canada, provides full administrative and financial support to the COSEWIC Secretariat.