The Santa Cruz long-toed salamander (Ambystoma macrodactylum croceum ) is an endangered subspecies of the long-toed salamander, which is found only close to a few isolated ponds in Santa Cruz and Monterey Counties in California. It has a black body, broken yellow or orange irregular striping along its spine, and a tail fin well evolved for swimming. Like other mole salamanders, it is found near pools or slow-moving streams and has a very secretive lifestyle, making it difficult to find.
Most of this salamander's adult life is spent in upland coast live oak forest in small animal burrows during the long dry season (May to October) in coastal California. Once winter rains have soaked the soil and filled ephemeral streams, both males and females migrate up to 2 km to breeding ponds that exist only in winter. In January, the males arrive at the ponds first, in time to prepare for a nighttime courtship. When the male and female have completed their courtship, the male deposits a packet of sperm, the spermatophore, in the water, which the female retrieves and uses to fertilize her eggs. She may lay the eggs singly or in loose clusters of six to eight eggs in shallow water 5–8 cm deep.Neither parent tends the eggs, which hatch into tadpoles in March and metamorphose into adult salamanders when the pond begins to dry out. The tadpoles commonly eat small copepods. Predators that eat long-toed salamander larvae include aquatic invertebrates, garter snakes, and other vertebrates. Other species of salamander tadpoles (larvae) compete with those of the long-toed salamander.
The breeding ponds of most species of long-toed salamanders completely dry up during the dry season. The year-round ponds likely harbor frogs, fish, and other aquatic predators that eat young salamanders, so these salamanders prefer ephemeral ponds. Most species of long-toed salamanders migrate up into nearby forests and do not spend any time near the breeding pond once they have metamorphosed and the pond is dry. A. m. croceum juveniles, though, often spend their first summer close to the breeding pond in a rodent burrow or rock fissure, only later migrating uphill into the forest. This may be because A. m. croceum breeding ponds retain water all summer.
Ambystoma macrodactylum croceum was designated as federally endangered in 1967 under the Endangered Species PreservationAct (a precursor to the Endangered Species Act of 1973), and endangered by the State of California in 1971;. It has also been designated as Critically imperiled at the global and state level by NatureServe. Its limited range and fragile specialized habitat place severe restrictions to the viability of this species. There is no definitive population estimate for the Santa Cruz long-toed salamander, but the numbers are deemed to be quite small. Further disturbance of its limited habitat could lead to this species' extinction.
