Population Survey Data for Coastal Giant Salamanders in the Chilliwack River Valley

The Coastal Giant Salamander (Dicamptodon tenebrosus, formerly known as Pacific giant salamander) is considered a species at risk (Assessed as Threatened by COSEWIC and red-listed by BC-CDC), and the primary putative threat in BC is forestry. Forestry operations impact both the aquatic and terrestrial habitats of the salamanders. Lack of forest cover exposes the adults to wider temperature extremes and the possibility of desiccation. Development of land for farming and settlement along Vedder Mountain and the Cultus Lake area has encroached on the B.C. distribution range of Dicamptodon tenebrosus. Adults depend on riparian forests, which are often removed by logging. In the streams, larvae (and neotenic adults) must cope with more variable stream flows, erosion and sedimentation of stream habitats, and increased water temperatures. This long-term (1994-2001) mark-recapture study of Coastal Giant Salamanders led by Dr. John Richardson (UBC) and Dr. William Neill (UBC) took place in 12 small streams in the Chilliwack River Valley, BC. This study includes survey data to assess whether forest harvest history near the streams or other geomorphic characteristics impacted density, survival, and growth rates. These data, the only long-term data using mark-recapture designs (CJS, using Lebreton design) for this species anywhere, will play a crucial role in future recovery efforts for this threatened species in Canada. The scientific value is high in understanding population dynamics and in the face of continued land use impacts and climate change, offering hope for the future of these salamanders.