Description

Tiger Salamanders are the largest land-dwelling salamander in the world. They can attain a total length of 40 cm, although generaly they are less than half of that. The tail makes up about half of their total length. The colour pattern is highly variable: spots, stripes or blotches on a dark background, or dark spots on a light background. Males have proportionally longer tails and hind legs than females.

Confusing Species

For much of its range in western Canada, the Tiger Salamander cannot be easily confused with any other salamander. In Manitoba, the Blue- spotted Salamander has the same stocky build, but its blue flecking easily distinguishes it from the Tiger Salamander. The Northwestern Salamander of British Columbia can have a similar background colour but it lacks the spotty or blotchy patterning of the Tiger Salamander and is only found along the Pacific coast. The Pacific Giant Salamander of British Columbia is most similar to the Tiger Salamander. It is blotchy, but its snout is more pointed than the Tiger Salamander.

Distribution

The Tiger Salamander can be found from the Okanagan Valley of British Columbia to southern Manitoba. There is a single historic record from Point Pelee in Ontario. Outside of Canada, they are found throughout most of the central United States as well as part of the Atlantic coast.

Habitat

Tiger Salamanders are adaptable to many types of habitats. They can exist in short grass prairie, aspen parkland, boreal forest and even subalpine areas. Although they can survive in very dry areas, they are generally not found far from water. Breeding occurs in permanent or semi-permanent ponds or lakes.

Reproduction

Breeding occurs after spring rains stimulate a migration to the breeding ponds. Pond temperatures can be as low as 10oC. Eggs are laid singly or in small groups on stones or aquatic vegetation. Within a month the larvae will hatch at approximately 1.5 cm in length. Sometime during the summer the larvae will transform into salamanders when they are about 10 cm long. In some lake populations the larvae do not transform, but reach maturity in the larval state. This strategy (neotony) is believed to occur when conditions are particularly harsh on land, or the aquatic habitat is particular safe -- a permanent, fishless waterbody.

Natural history

Outside of the spring breeding period Tiger Salamanders are not very conspicuous. They spend most of their time in subterranean burrows, which they can excavate themselves. Tiger Salamanders feed on a wide variety of insects, other invertebrates and even small vertebrates. They can live for over 15 years.

Conservation Concerns

Tiger Salamanders have been widely used as live bait in fishing. This has resulted in the introduction of Tiger Salamanders into areas where they are not naturally found. Game fish introductions into many lakes threaten neotonous Tiger Salamanders. Tiger Salamanders are designated endangered in British Columbia and extirpated from Ontario but have not apparently declined in other parts of the range.