Glacier harvestman

(Mitopus glacialis)

Distribution/habitat

As an endemite to the Alps, the glacier harvestman is found exclusively in the Alps. The arachnid is only found above the tree line, can survive even at 3,600 m altitude and thus advances higher up than any other harvestman. In Ötztal it populates the numerous glacier forefields (e.g. that of Rotmoosferner), which in addition to scarps and stone runs form its habitat.

Description/characteristics

Its body is patterned blue-greyish to black-white, with the female being some 9-10 mm large and the male 5.5-6 mm. The full span is up to 12 cm. The long, thin legs make it a speedy hunter. It grabs its prey, such as glacier fleas and other insects, with its fangs and swallows them whole. Like all other harvestmen, the glacier harvestman has scent glands. These contain a strong-smelling defensive secretion, which is emitted when threatened by a predator and slightly stuns the hunter. After mating, females mostly lay their eggs in hollows between rocks in the ground. The hatched youngsters shed their skin about four to eight times, until reaching sexual maturity. Adult animals can easily survive frost of down to -20°C, which in the mountains can occur even in summer.

Special features

The glacier harvestman is only found in the Alps and there in the very highest habitats. This is made possible by its cold adaptions developed during the last ice age. Climate warming makes temperatures rise and presents a problem to the glacier harvestman, as retreating to higher altitudes and colder areas is no longer possible.

Endangerment/protection

With progressive climate change, the glacier harvestman is likely to face increasing threats to its population.