TIGER SALAMANDER Ambystoma tigrinum Family Ambystomatidae - Mole Salamanders Order Caudata - Salamanders and Newts Risk Status Official status The Tiger Salamander is currently on the Provincial Red list (CDC=G5 S2). It has no official COSEWIC status. Risk Status Distinguishing Features Distribution Habitat Why is it endangered? Biology Sources for more information Museum Specimens Image Credits: sketch in Amphibians of British Columbia, Green and Campbell, 1992. Photos by Dick Cannings Distinguishing features The Tiger Salamander is the most widespread salamander species in North America and is one of the few that is capable of tolerating the dry conditions of many regions in the interior of North America. It is extremely variable in its markings and many subspecies are recognized. This is a large salamander that is smeared with yellow and black to form irregular blotches or vertical stripes. Two tubercles are present on the sole of each foot. There are no parotoid glands present. The Tiger Salamander in British Columbia has large blotches of yellow or dirty white on a black, grey or dark brown background. The borders of the blotches are often indistinct or they might join in such a way as to form a zebra-like pattern. The blotches extend down the sides and are not confined to the back nor do they ever form a distinct dorsal stripe. The belly is dirty grey while the legs and tail are mottled with light and dark patches. The head of the Tiger Salamander is round and relatively short but may have a pronounced snout. The eyes are fairly small and are widely spaced on the sides of the head. There are usually 13 costal grooves on the sides of the body. The well-developed legs overlap by three or four costal grooves when adpressed along the body. Each foot has two tubercles on the sole. Males have slightly longer tails than females and have swollen vents in the breeding season. Adult Tiger Salamanders may be as much as 200 mm long but generally average between 140 and 180 mm; the tail makes up about half this. The larvae of the Tiger Salamander are pond-type and have large gills and tail fins. The head is depressed and the eyes are rather small. The larvae of Tiger Salamanders may reach 75 to 80 mm before transforming. Paedogenic adults are sometimes called "mud puppies" and can reach lengths exceeding 20 cm. Neotenic individuals may occur in some localities, especially in deeper ponds or lakes. Distribution Map Red dots indicate specimen records or confirmed breeding sites. British Columbia It enters the Southern Okanagan Valley, reaching as far north as Summerland and Meadow Valley and east at least to Myer's Lake. Subspecies is the Blotched Tiger Salamander (Ambystoma tigrinum melanostictum ). North America The salamander has widespread but fragmented distribution across Canada with three subspecies being recognized in parts of British Columbia, Alberta, Saskatchewan, Manitoba and possibly Ontario. In the U.S.A., it occurs in the western states south to Wyoming and Nebraska and south down through eastern Mexico. Habitat Tiger Salamanders inhabit the dry southern interior of the province and are usually found near small, frequently alkali, lakes and ponds. They resist periods of drought by residing below ground. During the summer they hide below ground in abandoned mammal burrows or in other hollows in rotting logs or other subterranean hibernating sites (perhaps rocky areas). Generally, they are active near the surface only at night during or just after spring or fall rains or during their breeding migration in early spring or migration after metamorphosis. Otherwise, the adults are rarely seen. They also choose breeding sites that are adjacent to grassland foraging habitat with access to suitable alkaline lakes and ponds with prey availability. Why is it endangered? Development of lake margins for roads, agriculture, and housing is a main limiting factor in the distribution of Tiger Salamanders. Trampling of lakeside habitat by livestock impacts salamander eggs or larvae in small depressions near the water's edge because it causes the depressions to dry out, causing the eggs to desiccate. Soil compaction by livestock limits opportunities to gain subterranean refuge. Trampling of burrows by livestock, overgrazing or destruction of adjacent foraging habitat, and degradation of water quality are additional concerns. In permanent lakes, game fish and other predatory fish prey on salamander eggs and larvae. The fish have been introduced into lakes suitable for salamanders (e.g. Kilpoola and Frank Lakes). Also, poisoning of lakes for removal of coarse fish kills aquatic salamanders. The remaining populations in temporary ponds are subject to periodic drought. Water use for irrigation may lower water levels sufficiently to be detrimental to the salamander population. Improperly screened pumps cause mortality. Biology Breeding In early spring Tiger Salamanders migrate to nearby permanent or semi-permanent lakes and ponds to breed. There is no amplexus, instead courtship consists of much nudging, pushing and lashing of tails. Finally, the male will crawl ahead of the female and lifting his tail, lay a spermatophore for the female to pick up. There is a great deal of competition for mates when the salamanders congregate together. Males try to push and shove their chosen ones to more secluded spots but males will often interfere with one another's courting. Males also tend to lay their spermatophores on top of other spermatophores to cover them up. Many spermatophores are produced by a male during a bout of courtship. Eggs are laid shortly after mating, sometimes singly and sometimes in small masses. They are attached to stones, twigs or plants. The eggs hatch in two to three weeks. The larvae grow rapidly and transform in three to four months. They usually prefer warm areas of the pond where there is considerable growth of algae to hide in. The larvae eat aquatic insects and invertebrates and are not above cannibalism. Neoteny is frequent in the Tiger Salamander in many parts of its range. Another apparent adaptation to dry conditions is that some adults are paedogenic (individuals become sexually mature while retaining larval characteristics and an aquatic habitat). Although paedogenesis is common in many parts of the salamanders' range, only two paedogenic populations are known in British Columbia Several environmental factors are thought to influence paedogenesis. Behaviour Tiger Salamanders can live for up to 20 years. Cannibal morphs help to ensure population survival by ensuring that some of the population reach maturity in harsh conditions. Diet or Growing requirements Tiger Salamander's food consists of earthworms, insects or molluscs as well as the occasional frog or baby mouse. Neotonic Tiger Salamanders may live in deep, permanent pools. They will eat small fish, aquatic insects and worms or other larval Tiger Salamanders. Predators Predatory fish that have been introduced into interior lakes. Sources for more information Related On-line Sites to Visit Publications The Amphibians of B.C., Green and Campbell, 1992, p. 37 Habitat Conservation Fund, Species of Concern, August 1992 Living Landscape Directory of Researchers and their projects Museum Specimens this section sponsored by: Industry Canada

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