Pacific Giant Salamanders
The Pacific Giant Salamander is the largest land-based (as adults) salamander in Canada. The larval salamanders live in very small, steep streams along the Coast and Cascade Mountains from BC to California. Larvae may take up to four years to reach metamorphosis, and some individuals become sexually mature without ever leaving the stream, in a process called neoteny. The larvae are predaceous and live in pool areas of streams, often just downstream of a small cascade, where they find refuge under rocks.
Since 1994, Dr. William Neill (Zoology, UBC) and I have been studying the demography of over 12 populations of Pacific Giant Salamanders (PGS) in the Chilliwack River valley in southwestern British Columbia. The PGS is on BC’s Red List as a threatened species. The range of the species within BC is very restricted and the species reaches its northernmost range limit not very far north of the 49th parallel. There are several components to the overall studies, including population genetics (using microsatellites), recolonization dynamics, adult movements (using radiotelemetry), and detailed capture-recapture studies.
For over five years we have visited each stream site for up to five bouts of capture-recapture sampling. Individuals are measured and weighed, and each receives a PIT tag (passive integrated transponder) which allows us to identify each individual without having to leave any other marks on the animal. Repeated visits to the sites allow us to estimate survival (from month to month and overwinter), growth, and rates of movement around the streams.