Common Five-lined Skink Recovery Strategy Executive Summary
This document provides a summary of the recovery strategy for the common five-lined skink, which advises the ministry on ways to ensure healthy numbers of the species return to Ontario.
Prepared by D. C. Seburn
The Common Five-lined Skink (Plestiodon fasciatus) is the only lizard native to Ontario. Juveniles and some adults have five stripes that run down the back. Juveniles have bright blue tails, but the colour fades with age. Females typically lay a clutch of 9-10 eggs under cover, such as logs or rocks. The young mature in just under two years and typically live less than five years.
The Common Five-lined Skink is widespread in eastern North America, being found from Florida and Texas in the south to Minnesota and Ontario in the north. Canadian populations are limited to Ontario, where they occur in two disjunct areas: a small area in southwestern Ontario along the shorelines of Lakes Erie, St Clair, and Huron (Carolinian population) and along the southern edge of the Canadian Shield (Southern Shield population). Under the Endangered Species Act, 2007 (ESA) the Southern Shield population is listed as special concern, while the Carolinian population, reduced to only a few sites, is now listed as endangered. There is little information on abundance or trends across Ontario. The only intensive study of the Common Five-lined Skink is at Point Pelee National Park, where abundance declined as a result of disturbance to cover objects. Approximately 36 percent and 76 percent of element occurrences for the Southern Shield population and the Carolinian population, respectively, are considered either historic or extirpated. The Carolinian population has been reduced to six element occurrences.
The Common Five-lined Skink is associated with openings in, or edges of, deciduous forests. Within this broad category there is a wide range of habitats used including rocky outcrops, stabilized sand dunes, riparian forests, open deciduous forests and forest clearings. The Common Five-lined Skink is generally found in sandy areas in the Carolinian population and rocky areas in the Southern Shield population.
The major threat to the species is habitat loss and degradation from development. Disturbance is also a significant threat in the form of destruction or removal of cover objects used by Common Five-lined Skinks. Illegal collecting, traffic mortality and increased predation are also important threats.
A significant knowledge gap is that the complete distribution of the Common Five-lined Skink is not fully known. Other knowledge gaps include a lack of information on movements (habitat use, home range and dispersal), accurate population estimates for most sites in Ontario, and an assessment of the threat that succession poses to sites in Ontario.
A recovery goal has been prepared for each population. The goal for the Carolinian population is to ensure the long term survival of all remaining subpopulations. This recovery goal recognizes that some extant sites may not currently have enough suitable habitat to support the species in the long term. Increasing the amount of suitable habitat and microhabitat should be a high priority to ensure recovery of the species. The goal for the Southern Shield population is to ensure the long term survival of representative subpopulations across the range.
The recovery objectives for both populations are to:
- Determine the complete distribution of the Common Five-lined Skink in Ontario.
- Improve understanding of population estimates, spatial ecology and clarify uncertain threats.
- Develop and implement management measures to protect sites, reduce identified threats and increase available habitat.
It is recommended that any Ecological Land Classification unit containing a verified Common Five-lined Skink occurrence in the Carolinian population be prescribed as habitat in a habitat regulation. An exception to this approach is any observation outside of suitable habitat. Such an approach is recommended because it ensures all habitat elements required by the Common Five-lined Skinks (nesting, foraging, and hibernating sites) are regulated. Only sites with occurrences documented in the past 20 years should be prescribed as habitat in a habitat regulation for the population. This time period recognizes the cryptic nature of the Common Five-lined Skink and its ability to persist in even small pockets of suitable habitat. No area is recommended for habitat regulation for the Southern Shield population because as a special concern species the habitat protection provisions of the ESA do not apply.