Western Tiger Salamander: Size, Range and Life Cycle
The western tiger salamander (Ambystoma mavortium) is a stocky, burrowing salamander with dark skin and yellow bars or blotches. Adults are typically 15 to 22 cm (6 to 8.7 in) long. It spends most of its life underground and moves to fishless ponds to breed. Colorado Parks and Wildlife also calls the same species the barred tiger salamander.
Few salamanders are as widespread in the West. This one turns up in prairies, farm country and mountain meadows, and few people ever see it, because it lives in burrows.
Here is how to recognize it, where it lives, how it breeds, and how it fits with its look-alike relatives.
How this was made: prepared with AI assistance and checked against the sources listed at the end. Images are AI-generated illustrations, not photographs of real animals or products.
Key Takeaways
- Adults are typically 15 to 22 cm (6 to 8.7 in) long; Colorado gives a maximum of about 35 cm.
- Dark body with yellow bars or olive-to-yellow blotches.
- Adults live in rodent burrows and come out at night in damp weather.
- Breeds in fishless ponds, mostly from early spring to early summer.
- Some larvae keep their gills and breed without transforming.
- Montana calls the species common, widely distributed and stable.
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One animal, several names
Colorado Parks and Wildlife lists Ambystoma mavortium as the barred tiger salamander and notes it is also called the western tiger salamander. Wyoming reports three subspecies together because their life histories are alike and their ranges blend.
In practice, western tiger salamander covers the whole species. Barred and blotched are the names of regional forms. Read our posts on the barred tiger salamander and the blotched tiger salamander for those.
How to recognize it
Adults are stocky, with smooth moist skin, a broad head, small eyes and a long tail. Colorado counts 11 to 14 grooves along each side and four toes on each front foot.
The base color is black, dark brown or green. The pattern is vertical bars or many blotches, bright yellow for bars and olive green to pale yellow for blotches (Nebraska Herpetology).
The Montana Field Guide adds that tubercles on the soles of the feet separate adults from all other North American Ambystoma.
How big does it get?
Montana gives 15 to 22 cm (5.9 to 8.7 in) for typical adults. Nebraska gives 15.2 to 21.5 cm. Colorado gives a maximum of about 35 cm (under 14 inches).
These numbers differ because they describe typical animals versus the largest record. Use 15 to 22 cm as the usual range. See our tiger salamander size post for more.
| Source | Size given |
|---|---|
| Montana Field Guide | 15 to 22 cm (5.9 to 8.7 in), typical adult |
| Nebraska Herpetology | 15.2 to 21.5 cm (6.0 to 8.5 in) |
| Colorado Parks and Wildlife | Up to about 35 cm (under 14 in), maximum |
Where does it live?
Colorado says it is found statewide, from high mountains to low river valleys. Wyoming reports it throughout the state below about 10,000 feet. Montana records it across the prairies and parts of the mountains east of the Continental Divide.
The highest Montana site is 2,769 m (9,085 ft). Adults live in almost any habitat that offers burrowing soil and breeding water.
Life underground
Adults usually stay in self-dug or rodent burrows. Wyoming also lists cellars, window wells and manure heaps, which help them avoid drying out.
They are mostly terrestrial outside breeding season and need fairly moist conditions. Activity peaks at night, especially in damp weather.
What does it eat?
Adults eat insects, earthworms and other small invertebrates, and land adults may take small mammals, according to Wyoming and Montana. Larvae begin on aquatic invertebrates.
Some larvae turn cannibal. Colorado describes a cannibalistic form with a wider head, a slimmer body and large rounded teeth that eats bigger prey, including fathead minnows.
Breeding and development
Adults travel to shallow temporary or permanent ponds between March and June in Wyoming. Montana says breeding follows snowmelt, often in May on the prairie and from June to mid-August at higher elevations.
Eggs are laid singly or in small clusters of 5 to 120, and they hatch in about 15 days. Larvae usually transform at the end of the first summer, but may stay larvae for a second or third summer at high elevations.
Some larvae never transform. For that story, see our post on the paedomorphic tiger salamander.
Conservation and threats
Montana calls the species common, widely distributed and stable. Wyoming says populations are stable and that more than 30 new populations were documented over seven years.
Threats named by Wyoming include habitat fragmentation, energy development, road deaths during breeding migrations, trout stocking in mountain lakes, and disease such as ranavirus.
Frequently Asked Questions
Is the western tiger salamander the same as the barred tiger salamander?
Colorado Parks and Wildlife lists Ambystoma mavortium as the barred tiger salamander and also calls it the western tiger salamander.
How big is a western tiger salamander?
Typical adults are 15 to 22 cm (5.9 to 8.7 in). Colorado gives a maximum near 35 cm.
Where does it live?
Across much of the western United States, including Colorado, Wyoming and Montana, in burrows near fishless breeding ponds.
What does it eat?
Insects, earthworms and other invertebrates, and sometimes small mammals. Some larvae are cannibals.
Is it endangered?
Montana calls it common and stable, and Wyoming reports stable populations. Local threats include disease and habitat loss.
Does it stay in water?
Mostly no. Adults live underground and visit ponds to breed, although some individuals stay in the water as gilled adults.
What is the difference between western and blotched?
The blotched tiger salamander is a regional subspecies, Ambystoma mavortium melanostictum.
Bottom Line
The western tiger salamander is a quiet survivor of dry country. It hides, waits for rain and moves to ponds in spring.
If you are comparing forms, read next about the tiger salamander versus axolotl and the blotched tiger salamander.
Sources
- Colorado Parks and Wildlife: Barred tiger salamander, accessed Description, size, feeding forms, paedomorphs
- Montana Field Guide: Western tiger salamander, accessed Description, range, breeding, paedomorphs, status
- Wyoming Game and Fish Department: Tiger salamander species account, accessed Subspecies, habitat, development, threats
- Nebraska Herpetology: Western tiger salamander, accessed Size, color, diet, eggs
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