Townsend's mole (Scapanus townsendii) COSEWIC assessment and status report: chapter 8

Limiting Factors and Threats

The amount of available habitat for Townsend’s mole in Canada is likely limited to 20 km² around Huntingdon/Abbotsford (Sheehan and Galindo-Leal 1996). Threats are primarily from habitat degradation through farming and urban development. Townsend’s mole is considered an agricultural pest and farmers remove it from their cultivated fields and pastures. The constant tilling and application of fertilizers and pesticides on farms growing vegetables, berries and flowers create soils with poor structure and less earthworm biomass. Pesticides and farm equipment may kill moles directly.

Urban development threatens to fragment farmland habitat. Three 1:15,000 air photos are provided in the Appendix showing Huntingdon and Sumas Way going north to Abbotsford from 1972, 1983 and 1996. The habitat loss due to urban development is clear, as is the impact of the Agricultural Land Reserve (ALR) in containing the development to a narrow corridor; the farmland outside the developed areas is all in the ALR. The ALR lands are subject to changes in provincial governments and priorities

The compound average annual population change for the Fraser Valley Regional District that includes Abbotsford and Huntingdon from 1976-1996 was 3-4% compared with the provincial average of 2% (www.bcstats.gov.bc.ca (a)). Projected population growth for the region from 1996-2016 is 1-2% compared with a provincial expected average of 1.4% (www.bcstats.gov.bc.ca (b)). Such population growth will result in a loss of mole habitat outside the ALR.

The average farm around Huntingdon/Abbotsford is 25 ha (British Columbia Ministry of Economic Development 1986). Farmland in the area is lost to housing, although the moles may still survive in the lawns of residential development if not actively persecuted. The Lower Fraser Valley has 300,000 ha in the Agricultural Land Reserve, of which 29,000 were expected to be lost by the year 2000 (Moore 1990). Townsend’s moles may be restricted to fewer fields and be subjected to the negative impacts of species relaxation and numerous extinction vortices (Saunders et al. 1991).

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