Western Tiger Salamander
Western Tiger Salamander
Other names: Ambystoma tigrinum, Blotched Tiger Salamander, Barred Tiger Salamander, Tiger Salamander
Tiger Salamanders are members of the family Ambystomatidae, also known as the mole salamanders. This family is native to North America and are characterized by distinct and laterally compressed tails. Tiger Salamanders are the largest terrestrial salamanders after the Giant Salamanders, and are only active at night. In British Columbia, the Western Tiger Salamander can grow to over 30 cm in total length, although most individuals are between 15-20 cm. They have a robust body with 12-14 costal grooves, a broad head with small eyes, and a laterally compressed tail that is especially obvious in males. Tiger Salamander colouration shifts with age, with young individuals displaying light yellow or cream blotches or bars on a dark background, that changes to dark bars or blotches on a light background. Western Tiger Salamanders may also persist in forms, and can grow larger than terrestrial adults. Neotenic individuals are olive to greenish yellow with both front and back legs, a tail fin, and feathery gills.
Listen to the Indigenous words for “salamander” here!
In B.C., the Western Tiger Salamander may be confused with the Northwestern Salamander or the Coastal Giant Salamander, although their ranges do not overlap. No other species of salamander in the range of the Coastal Giant grows quite as large and has a marbled brown or gold patterning. The Northwestern Salamander also grows quite large, but has , and is usually a uniform dark colour.
Credit: Marcus Atkins
Western Tiger Salamander
Credit: John Clare
Credit: Dave Huth
Coastal Giant Salamander
Tiger Salamanders are widespread in North America with several subspecies. The Western Tiger Salamander occurs in Canada in southwestern Saskatchewan, southern Alberta, and the southern mountain region of British Columbia. Their range expands in the United States where it can be found south of the Canadian Border to Arizona, New Mexico, and Texas.
Adult Western Tiger Salamanders may be either terrestrial or aquatic (neotenic). Neotenic adults will only persist in permanent water bodies devoid of fish. Terrestrial adults spend most of their lives underground, using their forelimbs to burrow into soft and malleable soils. Western Tiger Salamanders are associated with Ponderosa Pine, Bluebunch Wheatgrass, and Douglas-Fir ecosystems. Terrestrial adults are found close to ponds and small lakes and may take shelter in small animal burrows or beneath coarse woody debris in damp areas. Tiger Salamanders are most often spotted at night during the spring breeding season, especially during rain events. In the summer months, adults will hunker down in burrows to escape hot and dry conditions. Tiger Salamanders will overwinter underground below the frost line either in burrows they excavate themselves, or old mammal burrows. In British Columbia, there is a positive association of Tiger Salamanders with Pocket Gophers, as old burrows provide easy access to subterranean (underground) habitat.
During warm spring rain events, Tiger Salamanders will emerge from their overwintering burrows and migrate to breeding wetlands, with males typically arriving before females. Breeding begins after an elaborate courtship. After breeding, females will attach eggs in clusters to submerged vegetation at least 30 cm below the surface. Females may lay anywhere from 100-5,000 eggs depending on location and body size. Hatching occurs within 2-3 weeks, with aquatic larvae metamorphosing into terrestrial juveniles in late summer, although some individuals will retain their larval features as adults and remain in aquatic habitats for their entire life, retaining their larval features (e.g., gills) while becoming reproductively mature adults. Sexual maturity is reached after 2 years for males, while females may take 3-5 years to mature, breeding only every other year. Western Tiger Salamanders are long-lived and may live to over 25 years of age.
Tiger Salamanders are opportunistic predators and eat a variety of invertebrates including insects, spiders, worms, mollusks, and leeches. Occasionally, Tiger Salamanders may also eat small vertebrates like mice. Aquatic larvae generally eat aquatic invertebrates, frog tadpoles, and larval salamanders . Cannibalism amongst Tiger Salamander larvae has been observed.
Western Tiger Salamanders are listed as ‘Endangered’ federally, and they are Red-Listed in British Columbia due to their restricted range, vulnerability to introduced fish, and the extensive loss of terrestrial habitat. The greatest threat to Western Tiger Salamanders in British Columbia is habitat loss and degradation, particularly wetlands. They appear to be vanishing at alarming rates in mountain valleys in British Columbia as land is being converted into urban areas, orchards, and vineyards. They are also sensitive to cattle grazing and off-road vehicles that disturb breeding ponds and surrounding soft-terrain that these salamanders use as burrowing habitat. Road mortality can also be a substantial threat to Tiger Salamanders where roads bisect spring migration routes to breeding wetlands. Pollution from herbicides, agricultural effluent, and road salt can be harmful to salamander populations as they easily absorb toxins through their skin. The introduction of predatory sport fish into breeding ponds and lakes can cause drastic declines in populations. Climate change and introduced pathogens are also potentially serious threats for Tiger Salamanders in British Columbia.
Did You Know?
Cannibalism has been observed in Tiger Salamanders when there are many salamander larvae relative to other food items in a pond. Some of the Tiger Salamander larvae will grow enlarged teeth and mouths, making them especially well-equipped to catch and eat other Tiger Salamander larvae. However, they appear to avoid eating larvae that are related to them and may be able to determine their brothers and sisters apart from unrelated individuals through smell!