Species Profile

Western Tiger Salamander Southern Mountain population

Scientific Name: Ambystoma mavortium
Taxonomy Group: Amphibians
Range: British Columbia
Last COSEWIC Assessment: November 2012
Last COSEWIC Designation: Endangered
SARA Status: No schedule, No Status

Individuals of this species may be protected under Schedule 1 under another name; for more information see Schedule 1, the A-Z Species List, or if applicable, the Related Species table below.


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Quick Links: | Description | Habitat | Biology | Threats | Protection | National Recovery Program | Documents

Image of Western Tiger Salamander

Description

Western Tiger Salamanders are among the largest salamanders in North America and are top predators in the largely fishless ponds and lakes where they occur. Terrestrial adults have a blotched, barred or reticulate pattern of yellow or off-white on a dark background. Genetic and morphological evidence indicates that the Western Tiger Salamander, consisting of several subspecies, is a separate species from the Eastern Tiger Salamander, Ambystoma tigrinum, with which it was previously combined as a single species. Much of the older literature does not necessarily distinguish the Western Tiger Salamander from the Eastern Tiger Salamander, as currently recognized. (Updated 2017/05/25)

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Distribution and Population

Western Tiger Salamanders have a wide distribution in arid interior regions of western North America. They occur along the border of the Prairie ecozone in Alberta, east to the Red River in Manitoba, south into western Minnesota and down to Texas, west along the border of Mexico and then north through Arizona and along the eastern slopes of the Rocky Mountains north to Alberta. There is a disjunct distribution in northern Oregon, Idaho and through Washington into the southern Okanagan region of British Columbia. Tiger salamanders in British Columbia are disjunct from populations in the remainder of Canada and occur in the Southern Mountain ecozone, whereas the remainder of the Canadian distribution occurs in the Prairie ecozone in Alberta, Saskatchewan and Manitoba. This distribution is likely the result of post-glacial expansion into Canada from at least two points on either side of the Rocky Mountains. (Updated 2017/05/25)

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Habitat

Western Tiger Salamanders occupy a variety of open habitats, including grasslands, parkland, subalpine meadows, and semi-deserts. Key habitat features include sandy or friable (crumbly) soils surrounding semi-permanent to permanent water bodies lacking predatory fish. Terrestrial Western Tiger Salamanders burrow actively into soil or utilize small mammal burrows for refuges and over-wintering. Breeding habitats must hold water for the 3 to 7 months required to complete larval development. Populations of completely aquatic neotenic adults (animals that retain larval form after sexual maturity) are occasionally found in cool, fishless lakes. (Updated 2017/05/25)

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Biology

Western Tiger Salamanders migrate to breeding sites in wetlands or lakes following spring rains soon after ice-off. Females lay eggs singly or in small clusters attached to twigs or stems of emergent plants below the water’s surface. Juveniles migrate en mass from breeding sites into terrestrial habitats in late summer. Males may reach sexual maturity in their second year, while females mature a year or two later. Generation time is approximately 5 - 6 years. Both larvae and adults are carnivorous and feed on a wide range of small prey. Western Tiger Salamanders do not fare well where predaceous fish have been introduced, or are naturally occurring, as all life stages are preyed upon. (Updated 2017/05/25)

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Threats

Tiger salamanders face the same pressures and threats as other amphibian species with separate requirements for terrestrial adults and aquatic larvae. Over much of the species’ Canadian range, there are immense pressures from loss, degradation and fragmentation of habitat. In the Prairies, a change has occurred in land use from grazing and low-scale agriculture to large-scale farming and conversion of habitat to accommodate growing urban populations and expansion of oil and gas developments. Within the core area of the species’ distribution in British Columbia, in the Okanagan Valley, there has been rapid habitat loss due to housing and vineyard developments with associated pollutant run-off. The introduced American Bullfrog poses an additional threat in this region. Increasing human populations and road densities have greatly increased the potential for road mortality during seasonal migrations between breeding sites and terrestrial overwintering and foraging habitats. Fish stocking for recreational fishing, aquaculture, and mosquito-control can have severe impacts on tiger salamander populations and continue to occur throughout the species’ Canadian range. The emergence of infectious diseases, specifically the widespread Ambystoma tigrinum virus, can decimate local populations. (Updated 2017/05/25)

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Protection

Federal Protection

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.

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Documents

PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.

3 record(s) found.

COSEWIC Status Reports

  • COSEWIC Assessment and Status Report on the Western Tiger Salamander Ambystoma mavortium in Canada (2013)

    Western Tiger Salamanders are among the largest salamanders in North America and are top predators in the largely fishless ponds and lakes where they occur. Terrestrial adults have a blotched, barred or reticulate pattern of yellow or off-white on a dark background. Genetic and morphological evidence indicates that the Western Tiger Salamander, consisting of several subspecies, is a separate species from the Eastern Tiger Salamander, Ambystoma tigrinum, with which it was previously combined as a single species. Much of the older literature does not necessarily distinguish the Western Tiger Salamander from the Eastern Tiger Salamander, as currently recognized.

Response Statements

  • Response Statement - Western Tiger Salamander, Southern Mountain population (2013)

    This large salamander has a range restricted to southern British Columbia which mostly overlaps with populated and modified agricultural areas in the South Okanagan Valley. The species has suffered loss of available breeding habitat through wetland draining, contamination, and stocking with fish. Salamander habitats are fragmented by roads and urban and agricultural developments that continue to expand, resulting in disruption of migration routes, mortality through roadkill, and loss of upland habitat for terrestrial adults. Increased drought and lowering water tables, as well as introduced Bullfrogs, also threaten this species.

COSEWIC Annual Reports

  • COSEWIC Annual Report – 2012-2013 (2013)

    Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings in this reporting year (October, 2012 to September 2013) from November 25 to November 30, 2012 and from April 28 to May 3, 2013. During the current reporting period, COSEWIC assessed the status or reviewed the classification of 73 wildlife species. The wildlife species assessment results for the 2012-2013 reporting period include the following: Extinct: 0 Extirpated: 2 Endangered: 28 Threatened: 19 Special Concern: 19 Data Deficient: 4 Not at Risk: 1 Total: 73 Of the 73 wildlife species examined, COSEWIC reviewed the classification of 50 species that had been previously assessed. The review of classification for 26 of those species resulted in a confirmation of the same status as the previous assessment.