Western toad (Bufo boreas) COSEWIC assessment and status report: chapter 12
Technical Summary
Bufo boreas
Western Toad – Crapaud de l’Ouest
Range of Occurrence in Canada:
YT NT BC AB Parks YFWMB
Extent and Area information
extent of occurrence (EO) (km²)
Based on map Fig. 3 in report: Ca. 1,300,000 km²
specify trend (decline, stable, increasing, unknown):
Stable
are there extreme fluctuations in EO?
No
area of occupancy (AO) (km²):
Ca. 130,000 km²
specify trend (decline, stable, increasing, unknown):
Decline especially on Vancouver Island and adjacent mainland
are there extreme fluctuations in AO ?
No
number of extant locations:
A great many
specify trend in #:
Decline especially on Vancouver Island and adjacent mainland
are there extreme fluctuations in # locations?
No
habitat trend:
Declining quality & extent especially on Vancouver Island and adjacent mainland
Population information
generation time:
3 – 4 yrs
number of mature individuals:
unknown
total population trend:
Decline especially on Vancouver Island and adjacent mainland
% decline over the last/next 10 years or 3 generations.
unknown
extreme fluctuations in number of mature individuals?
Most probably
is the total population severely fragmented?
yes
list populations with number of mature individuals in each:
unknown
specify trend in number of populations: Decline especially on Vancouver Island and adjacent mainland
are there extreme fluctuations in number of populations?
no
Threats (actual or imminent threats to populations or habitats)
- agricultural and urban development
- road traffic
- habitat deterioration, including fragmentation and the creation of unsuitable but attractive breeding ponds
- introduced exotic predators and competitors, especially bullfrogs and predatory fish
- diseases (Saprolegnia, chytridiomycosis)
- unknown factors implicated in US declines
- agricultural and urban development
- road traffic
- habitat deterioration, including fragmentation and the creation of unsuitable but attractive breeding ponds
- introduced exotic predators and competitors, especially bullfrogs and predatory fish
- diseases (Saprolegnia, chytridiomycosis)
- unknown factors implicated in US declines
Rescue Effect (immigration from an outside source)?
negligible
does species exist elsewhere (in Canada or outside)?
yes
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