| Abstract/Description or Keywords |
The objectives of this base-level amphibian assessment were to determine the West Kootenay distribution of all local amphibian species, provide a benchmark for future population monitoring and to survey for the chytrid fungus. This project is a follow-up to 1995 and 2005 amphibian surveys conducted in the East Kootenay which suggested that the Western Toad (Bufo boreas) has disappeared from several historic breeding sites (Ohanjanian et al. 2006). Surveys were conducted within the Interior Cedar-Hemlock (ICH) Biogeoclimatic Ecosystem Classification (BEC) zone of the Arrow-Boundary and Kootenay Lake Forest Districts, in south-eastern British Columbia. Field protocols were a combination of methods used in the 1995 and 2005 East Kootenay Amphibian Surveys (Ohanjanian et al. 2006), provincial inventory standards (MELP 1998) and the draft provincial Western Toad Monitoring Plan which is currently being developed (Wind in review). Thirty-eight random wetland sample sites were conducted through GIS analysis of TRIM data. Two additional non-randomly selected sites were also surveyed for a total sample size of 40. Visual encounter and dipnet surveys were conducted over 17 days from 7 July – 1 August 2008. Each site was visited once. Amphibians were found at 90.0% of the wetlands sampled and breeding was confirmed at 77.5% of the sites. The Columbia Spotted Frog (Rana luteiventris) was found at most sites (72.5%) followed by the Pacific Chorus Frog (Pseudacris regilla) (42.5% of sites), Long-toed Salamander (Ambystoma macrodactylum) (40.0% sites), Western Toad (Bufo boreas) (27.5% of sites) and Northern Leopard Frog (Rana pipiens) (2.5% of sites). Breeding-site encounter rate for the Western Toad was 0.225 compared to 0.040 in Southeast Alaska (Payre et al. 2007) and 0.193 in the East Kootenay (Ohanjanian et al. 2006). This suggests that our region may be an important breeding region for the species. Amphibian species richness was also higher than that reported in the East Kootenays (Ohanjanian et al. 2006). Eleven sites (27.5%) had one species present, 15 sites (37.5%) had two species, seven sites (17.5%) had three species and three sites (7.5%) had four species present. Amphibian species richness was greater at sites where fish were not observed. American beaver activity was noted at 40.5 % of the wetlands. Most (72.5%) of the sampled wetlands were small (<10 ha) and were classified as marshes according to the provincial wetland classification standard (MacKenzie and Moran 2004). Of the forty-six chytrid samples taken from 22 site, two tested positive. In our opinion, randomly selecting wetlands sample sites through GIS using TRIM data is an effective way to satisfy the requirements of occupancy modeling and these sites are good candidates for future amphibian monitoring using proportion of area occupied (PAO) analysis. In order to determine occupancy rates for each amphibian species, we recommend sampling each site at least twice over the breeding season, preferably with two observers collecting data independently. There were some issues with the collection of several covariates—mainly involving standardizing and quantifying survey effort. Larval trapping could be used in the future to provide additional and more reliable amphibian presence data. Wetland classification using MacKenzie and Moran (2004) was sometimes difficult and additional habitat data may need to be collected in the future. We recommend incorporating a wetland “health” assessment methodology which was recently tested in the East Kootenay (Ross et al. 2006). Government agencies, conservation organizations and consultants throughout British Columbia are initiating amphibian monitoring plans. Because of this, there is a great need for the roles and responsibilities of all groups with regard to leadership, coordination, communication, funding, data ownership and standardization etc. to be discussed and clarified. We should continue to standardize our methods with province- and continent-wide amphibian monitoring efforts while creating an effective and custom-made monitoring plan for the entire FWCP area. The completion of this base-level amphibian assessment is a first step toward mid-level amphibian monitoring and we recommend continuing and expanding base-level amphibian monitoring throughout the FWCP project area. If long term monitoring reveals that regional amphibian species are in decline, apex-level monitoring efforts may help determine the causes. Habitat management could include actions such as stewardship outreach, land use planning, land acquisitions, protection of breeding areas and connectivity corridors, mitigating for road mortality and habitat enhancement or restoration. Non-habitat management tools might include captive breeding, population augmentation and translocations, non-native species control and predator or competitor control. These actions would require follow-up monitoring to ensure their efficacy. |
