Adult tiger salamanders are usually terrestrial and spend most of their lives underground, either in a burrow they have dug themselves or in the burrow of another animal (1) (2) (3) (5) (6) (8). Individuals of this species have been found up to two metres below the soil surface (2). Members of the family to which the tiger salamander belongs, the Ambystomatidae, are commonly known as ‘mole salamanders’ due to this predominantly underground existence (3) (4).
On rainy nights between late winter and early spring, the adult tiger salamander migrates from its burrow to its breeding ponds (2) (5) (6) (7) (8). These ponds normally lack fish, which may prey on the salamander’s eggs and larvae, and range from clear mountain pools to temporary lowland ponds, farm ponds, gravel pits, ditches and ornamental ponds (1) (2) (5) (6) (7).
Male tiger salamanders typically arrive at the breeding grounds a few days before the females (2) (3) (6) (7). Courtship takes place at night and involves the male nudging the female with his snout, possibly to move her away from other males, before leading her forward. The male then deposits a package of sperm known as a spermatophore, which the female picks up in her cloaca (6).
The female tiger salamander lays rows or clusters of eggs on submerged vegetation or on the bottom of the pond (2) (5) (6) (7). Each egg mass contains up to 100 or so eggs (3) (6) (8), and each female may potentially produce several thousand eggs in a breeding season (2) (7). The tiger salamander’s eggs hatch in about two to six weeks, depending on the water temperature (6) (7) (8).
The larvae of this species measure around 1.3 to 1.7 centimetres in length on hatching (6), but grow rapidly, sometimes reaching 10 to 15 centimetres in length before they metamorphose (2) (3) (6) (7). Tiger salamander larvae can undergo metamorphosis at around ten weeks old (2), but many take much longer, sometimes even overwintering in the pond and transforming the following spring (2) (6). After metamorphosis, the newly transformed adult salamanders usually migrate away from the water (2). The tiger salamander may be able to breed at a year old (3) (6) (7).
Adult tiger salamanders feed on a variety of insects, worms, snails, slugs, and even small vertebrates, such as mice, frogs and lizards. The larvae of the tiger salamander eat any prey which can fit into their mouths, including small crustaceans, insect larvae, molluscs, leeches, frog tadpoles, other salamander larvae, and even small fish (2) (3) (6) (7) (8). ‘Neotenic’ adults, which remain aquatic, have a similar diet to the larvae (2).
The tiger salamander’s eggs and larvae are vulnerable to a wide range of predators, including aquatic insects, newts, larger salamander larvae, birds, snakes and fish, and only a small number reach adulthood. Adult tiger salamanders may be taken by snakes, birds and mammals (2) (6) (7) (8), but those that survive can potentially be quite long-lived (5) (6), with individuals in captivity reaching over 20 years old or more (2) (5) (6). To deter potential predators, the adult tiger salamander produces noxious secretions from glands on the upper surface of its tail, and may raise and lash its tail if threatened (2) (6) (8).