If the female accepts the males courtship, the male directs her snout toward his vent region while both move forward stiffly with pelvic undulations. As the female follows, the male stops and deposits a spermatophore, and the female will move forward with the male to raise her tail and receive the sperm packet. The full courtship dance is rarely accomplished in the first attempt. Females deposit their eggs a few days after mating. In some lowland areas the adult salamanders will remain active all winter long, excluding cold spells. However, during the cold winter months in the northern parts of its range, the long-toed salamander burrows below the frost-line in a coarse substrate to hibernate in clusters of 8–14 individuals. While hibernating, it survives on protein energy reserves that are stored in its skin and along its tail. These proteins serve a secondary function as part of a mixture or concoction of skin secretions that is used for defense. When threatened, the long-toed salamander will wave its tail and secrete an adhesive white milky substance that is noxious and likely poisonous. The color of its skin can serve as a warning to predators ("aposematism") that it will taste bad. Its skin colors and patterns are diverse, ranging from a dark black to reddish brown background that is spotted or blotched by a pale-reddish-brown, pale-green, to a bright yellow stripe. An adult may also drop part of its tail and slink away while the tail bit acts as a squirmy decoy; this is called "autotomy". The regeneration and regrowth of the tail is one example of the developmental physiology of amphibians that is of great interest to the medical profession. While the long-toed salamander is classified as least concern by the IUCN, many forms of land development negatively affect the salamander's habitat and have put new perspectives and priorities into its conservation biology. Conservation priorities focus at the population level of diversity, which is declining at rates ten times that of species extinction. Population level diversity is what provides ecosystem services, such as the keystone role that salamanders play in the soil ecosystems, including the nutrient cycling that supports wetland and forested ecosystems. Two life-history features of amphibians are often cited as a reason why amphibians are good indicators of environmental health or 'canaries in the coal mine'. Like all amphibians, the long-toed salamander has both an aquatic and terrestrial life transition and semipermeable skin.