| Citation |
Ohanjanian, P, D. Adama, and A. Davidson (2006) An Amphibian Inventory of the East Kootenays with an emphasis on Bufo boreas, 2005, Consulting biologist, Adama Wildlife Consulting, Wildlife Technician. Prepared for Fish and Wildlife Compensation Program - Columbia Basin. Prepared for Fish and Wildlife Compensation Program - Columbia Basin. |
| Abstract/Description or Keywords |
Amphibians have experienced declines throughout the world. The western toad, Bufo boreas, has undergone rapid declines in the western US, but its status in south-eastern British Columbia is unclear. The objectives of this project were to 1) carry out amphibian inventories at wetlands throughout the East Kootenay 2) determine presence of western toad at historical breeding sites 3) re-survey historical northern leopard frog sites 4) collect tissue samples for future disease diagnostics and 5) provide recommendations. The study was located in the southern Rocky Mountain Trench. We carried out Visual Encounter Surveys at 57 wetlands from 29-Jun to 10-Oct, 2005. Survey sites included 23 historic toad breeding sites and 11 historic northern leopard frog occurrence sites. Visits to toad breeding sites were timed to maximize the probability of detecting tadpoles. To prevent the potential transfer of pathogens between sites all gear was disinfected. Environmental conditions, survey effort and wetland attributes were recorded. Amphibian species and developmental stages were identified, and snout-tovent lengths and weights of metamorphs, juveniles and adults obtained. To assess chytrid prevalence, toe clips and swabs were collected and preserved for future lab analysis. UTMs of all amphibian sightings were recorded and maps depicting amphibian distribution were generated. Amphibians were detected at 27 of 57 sites. Western toads were found at 12 sites. Toad breeding was confirmed at 30.4% the 23 historic breeding locales visited in 2005. Other species detected were Columbia spotted frog (14 sites), long-toed salamander (6 sites) Pacific chorus frog (3 sites) wood frog (1 site) and tailed frog (1 site). No northern leopard frogs were detected. We observed >1 species at only 7 of 57 sites. Although western toads and spotted frogs were detected in a wide geographical area, the actual number of occurrence sites was low. Gross inspection of 92 amphibians revealed no obvious disease-related morbidity. Tissue samples and swabs were obtained from 24 animals for future PCR testing for chytrid. Recent research has shown that chytrid has a profound effect on B. boreas tadpoles. In 2005, metamorphosis was only confirmed at 2 toad breeding sites; we cannot say with certainty that reproduction was successful at 9 other sites based solely on the observation of tadpoles. This report provides preliminary evidence that a decline in western toads may be underway in southeastern British Columbia. To substantiate this, a statistically sound, multi-year monitoring program should be initiated. The issue of chytridiomycosis must be investigated, including tissue sampling and lab analysis. The presence of toad tadpoles alone does not indicate successful reproduction - surveys must continue through to metamorphosis and beyond. All future amphibian surveys should follow a rigorous disinfection protocol to prevent the spread of pathogens between ponds. |
