West Babine Sustainable Resource Management Plan

. Habitat-related issues
Grizzly bears require habitat that provides for their nutritional, security, thermal,
reproductive and “space” needs. It is difficult to generalize about habitat requirements for
grizzly bears in B.C. because the bears have such a wide range of behavioural adaptations to
the diverse ecosystems that occur in this province. Although meeting nutritional requirements
is the primary factor in habitat choice, selection is also based on thermal cover (e.g.,
dens/bedding sites), security (e.g., females protecting cubs), or access to potential mates
during the breeding season. Habitat selection is also strongly influenced by social
interactions between bears and the presence and activities of people.
Because bears employ a variety of strategies to meet habitat requirements, management of
grizzly habitat must be considered at several spatial scales – from specific food-producing
stands and microsites (= critical habitats), to landscape level forage supply, to habitat supply
at the population unit scale. Habitat must also be considered over various time scales to
account for continually shifting seasonal food supplies and annual food variance (e.g., berry
crop failure) as well as longer-term changes in landscape condition.
Critical habitat
Critical habitats are areas that are considered essential for bear survival. These areas have
high forage, bedding or proven denning value, particularly in situations where these habitats
are in short supply. Critical habitat areas tend to receive repeated and/or prolonged use by at
least one bear. Overall, these relatively small areas of habitat can contribute in a large way to
the overall seasonal requirements of a bear, and thus of a population.
Critical habitat areas are defined at the stand level and are typically one to five hectares in
size. Critical habitats in the West Babine include herb-dominated avalanche tracks with
adjacent forest; non-forested fens; herbaceous riparian meadow/wetland complexes and
seepage sites; skunk cabbage swamps; subalpine parkland meadows; salmon fishing areas
(e.g., Grizzly Drop); and old burns or other successional areas dominated by Vaccinium
(blueberry or huckleberry) species. Non-forested critical habitats include a core area and
buffer of forested cover. Patches of forested critical habitat do not require an additional
forested buffer.
Habitat effectiveness
The Wildlife Branch has estimated grizzly bear populations for each Wildlife Management
Unit of the province under the Grizzly Bear Conservation Strategy. This estimate is based on
habitat capability (because of the impracticality of census), “stepped down” for the existing
levels of habitat loss, habitat alteration, displacement, fragmentation and mortality in each
Management Unit. These estimates are presented for Management Units 6–7, 6–8 and the
plan area in Table 6, page 24.
March 2004 Page 23