Abstract

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Lang, J.W. 1982. Distribution and abundance of the five-lined skink (Eumeces faciatus) in Minnesota. Final report submitted to Nongame Wildlife Program, Minnesota Department of Natural Resources. 109 pp.

Abstract:

The five-lined skink (Eumeces fasciatus), a small smooth-scaled lizard, occurs in southwestern Minnesota as a disjunct population(s) on rock outcrops in a restricted region of the upper Minnesota River valley. Determination of the species' status in the state requires detailed and accurate data on its current distribution and abundance - the objectives of the present study.

Fieldwork was carried out in May-July 1982; suitable habitat was located and surveyed fro skinks. A total of 119 captures/sighting were recorded. The species was found on 26 specific sites at three localities between Granite Falls and Redwood Falls. Each locality (Swedes Forest, Delhi, and South Granite Falls) is described with respect to location, distribution, suitable habitat, skink populations, and land ownership and use. Skinks occur in high densities in favorable habitat, but skink distribution is patchy. Estimated population sizes range at maximum levels from 45,900-3600 to 4590-360 at minimum levels and vary considerably among localities. Suitable habitat is characterized by 1) proximity to bedrock exposures, 2) open sunny areas, 3) abundant cover, and 4) access to water. Bare rock openings with large and small loose rock for cover are the preferred habitat, but disturbed areas that are open and near rock outcrops are also favored. Activity and hence habitat requirements change seasonally; skinks are very active in the early spring and summer but not later in the season.

Dense stands of eastern red cedar now cover many rock outcrops which were formerly (prior to 1930s & 1940s) devoid of vegetation. Open areas on rock outcrops in 1938 occupied three times the area occupied in 1968. If cedars continue to encroach into openings at the present rate, openings will virtually disappear by 1990. Skink populations have probably declined with the reduction in the "openness" of rock outcrop habitat, and will likely continue to decline in the future as openings on the rock exposures are vegetated.

In many important life history attributes, e.g., growth rate, age of maturation, annual reproduction, the Minnesota population(s) of five-lined skinks are similar to populations in Kansas. Prairie skinks (Eumeces septentrionalis) were found at the same sites and in the same habitats with five-lined skinks. Prairie skinks appear to be inhabiting rock outcrops as these become vegetated; if so, then interactions between these two skink species may ultimately affect the distribution and abundance of five-lined skinks in Minnesota.

Protection and management of suitable skink habitat is recommended as well as prohibition on collecting/taking. Specific recommendations have been formulated for the three localities. The major threat to the species' continued existence in Minnesota appears to be the loss of suitable habitat due to the spread of eastern red cedar on previously exposed bedrock; management by controlled burning, selective cutting, etc. is considered essential. Furthermore, additional fieldwork is needed at the South Granite Falls locality and in areas south of Delhi. An appropriate public relations program is desirable in order to acquaint local residents and visitors with the various species, including skinks, which live on the rock outcrops. Specific recommendations are advanced for the overall protection, preservation, and management of the rock outcrops together with the plants and animals which inhabit this unique natural feature of the Minnesota landscape.

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