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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.
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
Museum Specimens
this section sponsored
by: 
Industry Canada
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