The Alpine Salamander: A Black Beauty of the Mountains
The alpine salamander (Salamandra atra) is a black salamander that can be found in the French Alps, and through the mountainous range in Europe. It is a member of the genus Salamandra, which includes other species of fire salamanders. Their species name, atra, may be derived from the Latin ater, meaning dull black. The salamanders’ coloration has evolved over time, as some species are completely monochrome black and others have yellow spotting and marks. Their life expectancy is at least 10 years. There are four subspecies of the alpine salamander, with varied distribution and physical coloration. Unlike other salamanders, whose larvae are developed in water, the alpine salamander and its subspecies are a fully terrestrial species in life and gestation. They give birth to live young. Alpine salamanders produce toxic compounds from their skin. These compounds may protect them from both predator and microbial threats.
Alpine salamanders are often small in size, and dark brown or black. Members of the subspecies are not wholly black or brown monochrome, but rather have mosaic or spotted patterns. Members of the subspecies Salamandra atra aurorae have bright splotches on its dorsal side and head. The color is often bright yellow, but can range to shades of white or even gray. Distribution of the pigment is dependent on the distribution of certain cells, so may be smooth and even or patchy. Female S. atra tend to be larger than the males, and can grow up to 151 millimeters, or around 5.9 inches. Males will grow to around 144 millimeters, or 5.6 inches: both measurements include the tail. Males have swollen, visible cloacae, and are more slender than females. The salamanders have parotid glands posterior and lateral to their eyes, giving them an elongated head shape. They tend to have between 11 and 13 costal grooves along the sides of their bodies, and a double row of dorsal glands runs down their backs on either side of their spines, down to the tips of their tails.
Distribution and Habitat
The alpine salamander can be found in the Alps from the Swiss-French border at the western end of its range through Austria to the Dinaric Alps at the eastern end of its range, at altitudes above 700 m (2,300 ft). They prefer moist habitats such as forests, meadows, pastures, and rocky areas with crevices and caves. They are active mostly at night or during rainy days, and hide under stones, logs, or leaf litter during dry or sunny periods. They are cold-tolerant and can survive temperatures below freezing.
Diet and Predators
The alpine salamander is a carnivore that feeds on various invertebrates such as insects, spiders, worms, slugs, and snails. They use their sticky tongue to catch their prey by flicking it out quickly. They may also use their teeth to grasp larger prey items. They have few natural predators due to their toxic skin secretions, which can cause irritation, inflammation, or even death in some animals. However, some birds such as crows and ravens may prey on them by pecking out their internal organs while avoiding their skin.
Reproduction and Life Cycle
The alpine salamander is one of the few salamanders that give birth to fully developed young instead of laying eggs or having aquatic larvae. They mate on land during summer or autumn, and the females store the sperm in their oviducts until fertilization occurs about two years later. The gestation period lasts for another two to three years, during which the embryos feed on their own yolk sacs and then on the oviductal secretions of their mother. The females give birth to one or two live young per litter, which are about 50 mm (2 inches) long and look like miniature adults. The young are independent from birth and reach sexual maturity at about four to six years of age.