Because of their secretive habits and cryptic colouration, snakes are often overlooked and considered to be of insignificant ecological value. However, such prejudices are likely the result of poorly informed judgement, as all snakes are predators and it is likely that many play important roles in the dynamics of energy flow through ecosystems. The contribution of snakes to the health of local biological systems should not be underestimated.
In British Columbia, six of the nine snake species have been placed on the provincial Blue-list (vulnerable or sensitive) or Red-list (endangered or threatened) due to loss of habitat and persecution. All nine species that occur in the province represent northern populations of animals that are more widely distributed at southern latitudes (in the United States). A large portion of British Columbia has severe climatic conditions, making it uninhabitable to most species of snakes. For this reason, northern populations may be unique, as they are likely genetically distinct from those in the south. They also exhibit unique ecology, presumably reflecting adaptations to northern extremes (Macartney and Gregory 1988).
Land use planning to conserve snakes in British Columbia requires reliable information about population sizes and viability, species distribution, and temporal trends. Such information is of particular necessity to snakes, as the ecology of most species is poorly known and, in most cases, even the most rudimentary natural history information is lacking. The prime objective of this manual is to recommend methods and protocols which are currently used by experienced herpetologists to sample snakes in the field. Because snakes are poorly studied and unfamiliar to most biologists, we also provide descriptions of the nine species and summarize broadly the known features of their natural history.