Ambystoma tigrinum
(Tiger Salamander)

Key Characteristics:

General Description:
These heavy-bodied salamanders are the largest representatives of the family Ambystomatidae (up to around 13 inches total length). They are variably colored, ranging from black, tan or olive ground color and olive, yellow or tan markings (some have almost no markings at all). The blotches generally form a marbled pattern.  Tiger Salamanders have evident costal grooves along their sides, and their eyes seem to protrude from their large head.

The larvae of this species are adapted for pond habitats and consequently have certain larval characteristics such as long delicate external gills and a wider fin along their tail. Tiger Salamander larvae can be distinguished from larvae of Long-toed Salamander and Rough Skinned Newts because they have more than 16 gill rakers on the third gill arch. Tiger Salamander larvae also lack balancers (these are two small growths from the sides of the head in young larvae).

The eggs of this species are about 2.5mm across and are laid in linear clumps ranging from a single egg to 120 eggs. Tiger Salamander eggs are pigmented brown dorsally (Nussbaum et al. 1983) and are generally attached to submerged plants or debris.

Idaho Distribution:
In Idaho, Tiger Salamanders can be found in suitable habitat in the eastern part of the state, the western edge of the panhandle and in some southwestern areas.

Habitat:
Found in virtually any habitat, providing there is nearby body of water suitable for breeding. In Idaho, suspected to be present in scattered populations throughout appropriate habitat of grasslands and shrub steppe.

Tiger Salamanders are generally found in ponds, small lakes or slow moving streams in grassy or sagebrush cover. These secretive salamanders are not often encountered as they are largely fossorial. They are sometimes found out in the open on moist evenings following rains. The aquatic larvae can be abundant in ponds or wetlands with limited aquatic vegetation (Stephen Burton, unpubl. data).

Feeding:
Adults eat any small animal that can be captured and swallowed. Larvae eat aquatic invertebrates and vertebrates (especially amphibian larvae) as available.

Ecology:
Hibernates/aestivates. Activity is often associated with rainfall. Inactive in winter in colder climates. Terrestrial adults are usually underground in self-made burrows, or in those made by rodent or other animals. In some years, drying of breeding pond may result in total reproductive failure.

Reproduction:
Lays up to 1000 eggs, singly or in small clusters, on submerged vegetation. Larvae metamorphose in first or second summer, or become paedomorphic. In Idaho, breeding occurs in spring.

Conservation:

Status:	Unprotected nongame species
Global Rank:	G5
State Rank:	S5