Rubber boa (Charina bobttae) COSEWIC assessment and status report: chapter 5

Habitat

Habitat requirements

Rubber Boas occupy a wide variety of habitats including riparian, chapparal, grassland and montane forest (Hoyer 2001; Gregory and Campbell 1984; Stebbins 1966). In Western Oregon, the Rubber Boa occurs in most habitats except where regular grazing and cultivation are practiced, and has even been captured in vacant city lots, near railroads and highways, and in areas adjacent to industrial plants (Hoyer 1974). The major habitat requirement appears to be an abundance of coarse woody debris (Hoyer and Stewart 2000a; Cannings et al. 1999) which the snakes use for protective cover and to aid in thermoregulation (Dorcas and Peterson 1998). As well, artificial cover (such as plywood) has proven to attract Rubber Boas; the capture rate of Rubber Boas in southern California under artificial cover was one every 34 minutes compared with one every 2 hours and 29 minutes under natural cover (Hoyer and Stewart 2000a). Rubber Boas also spend a considerable amount of time underground in rock crevices and abandoned rodent burrows (Dorcas and Peterson 1998). Telemetry data from the Creston Valley population in British Columbia indicates that Rubber Boas spend 25% of their time under cover and the rest underground (St. Clair 1999). These boas are found primarily in rocky outcrops in forest clearings. There is some evidence to support that Rubber Boas select rocks of varying thicknesses and, therefore, varying temperatures, to regulate body temperature (R. St. Clair, unpublished data).

Trends

Increasing urbanization, intensive agriculture and forest practices that remove coarse woody debris are all likely to cause a decrease in the amount of suitable habitat available to Rubber Boas.

Protection/ownership

Under the British Columbia Forest Practices Code, the Rubber Boa is considered ‘Identified Wildlife’ (at some level of risk) and consequently forest licensees are legally obligated to manage areas of harvest that provide critical habitat for the snake. Critical habitats include breeding, den and feeding sites. Unfortunately, such specific information on habitat use is not available for the Rubber Boa. The Creston Valley population is protected within the Creston Valley Wildlife Management Area.

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