
© Stefan Zurschmitten
Fauna
The Binntal valley is home to an extremely diverse fauna. Many species are found only here in Switzerland or have their main distribution here.
The steep relief of the Binntal valley has always successfully prevented overly intensive use. In the Binntal Landscape Park, extremely dry and rocky slopes on the sun-exposed side of the valley form a stark contrast to the wooded, rather damp slopes on the shady side. In simplified geological terms, a distinction can be made between the southern side of the valley, which is dominated by alkaline rocks, and the northern side, which is dominated by acidic rocks. These geological and topographical features as well as the extremely dry and sunny climate of the Valais have led to an exceptionally rich fauna in the Binntal Landscape Park, whose park area extends from the lowest altitudes at around 1000 m above sea level to the regions of perpetual snow.
Apollo butterfly
The Apollo butterfly Parnassius apollo belongs to the knight butterfly family. This group includes the most beautiful and largest butterflies of our native fauna. Already extinct or highly endangered in other European countries, the butterfly can still be observed quite frequently in the Binntal Landscape Park. The butterfly can be found on almost all dry slopes in the region. The striking, bright red spots of color on a white wing base mimic eyes and are intended to scare off predators. The mating behavior is also special: After mating, the male glues the female's mating hole with a hardening substance and thus prevents the female from mating again.
Asp viper
In Switzerland, the asp viper Vipera aspis is mainly found in the Alps, Pre-Alps and Jura. The Binntal can be described as a hotspot for this snake species. There are several areas where the species still occurs in very good numbers. After spending the winter in torpor, aspis vipers are all the more active in spring, as they need to warm up in the sun and the mating season begins. In late summer, the young are born alive from the mother (without laying eggs). The animals are generally very shy and flee when approached by humans. Incidents are therefore very rare and generally unproblematic.
Black mortar bee
In contrast to the colony-forming honeybees and bumblebees, the black mortar bee Megachile parietina, which is more reminiscent of a bumblebee in terms of its size and black coloration, lives a solitary life: a single female builds concrete-hard nests made of mortar (clay, small stones) in depressions and uneven areas of stones and rocks, which consist of 5-10 brood cells. They provision these cells for their larvae solely with sainfoin (Onobrychis sp.) pollen, which takes 2-3 days per brood cell in good weather. A few occurrences of this very rare species are known in the Landscape Park, which are being preserved through targeted support measures.
Chamois
The Latin name Rupicapra rupicapra means "rock goat" and describes them very aptly. These mountain dwellers, which are also distantly related to our domestic goat, are skilled climbers that deliberately seek out steep and inaccessible rocks to protect themselves from predators, especially when they have young. Males and females live separately almost all year round. Only during the mating season in November/December do the males join the female packs and fight fiercely for the females. Both sexes of chamois have horns, which they keep for the rest of their lives.
Crag martin
The cliff swallow is a very common sight in the Binntal Landscape Park. It once only colonized Mediterranean areas. In recent decades, however, the crag martin has spread further and further north - as far as the canton of Jura and Lower Austria. As a cliff-nesting bird, it prefers to live and nest in rugged rocky terrain. In recent years, there has been increasing evidence that it is also breeding in urban areas. It finds sheltered nesting opportunities on the ledges of buildings and roofs, where it builds its cup-shaped nests with clay mortar. In the hamlet of Heiligkreuz, as in the other villages in the park, it is therefore worth keeping an eye out for cliff swallows and their nests under the roofs and gables.
Emerald lizard
The emerald lizard Lacerta bilineata is found in Switzerland exclusively in the climatically favorable southern parts (Geneva, Valais, Ticino and Grisons) and, with a body length of more than 30 cm, is the giant among the native lizard species. In the Valais dialect, it is called "Grienig", which means "green lizard" and refers to its emerald green coloration. However, only the males are so magnificently colored: In their wedding dress in spring, they show off their bright blue throats during territorial fights with other males. The females live much more hidden and are therefore less conspicuously brownish-olive green in color.
Escher blue butterfly
In Switzerland, the critically endangered Escher blue Polyommatus escheri only occurs in the cantons of Valais and Grisons, with the main distribution area in Valais. Switzerland is also the main international distribution area for this butterfly species, which means that it bears a great deal of responsibility. The caterpillar lives almost exclusively on the butterfly flower "French tragacanth". In the Binntal, this blue butterfly colonizes open pine forests and dry meadows, where it also finds the caterpillar food plant. The beautiful blue tones on the wings of the males are not caused by a dye, but are due to pure light refraction effects.
Large mantis shrimp
The large mantis Arcyptera fusca is one of the most colorful and largest native grasshoppers. The species is unmistakable due to its imposing body size and yellow-black ringed hind legs with bright red rails, making it easily recognizable even to laypeople. In August, the mute grasshoppers are in peak season and the males make entire mountain meadows resound by rubbing their hind legs against the edge of a wing (stridulating). They use this song to attract females. Throughout Switzerland, around two thirds of the population of the greater mute grasshopper is found in the canton of Valais, which is why the canton bears a great deal of responsibility for its conservation.
Marsh Grasshopper
The marsh grasshopper Stethophyma grossum is very similar in size and coloration to the large grasshopper, but lives in a completely different habitat. While almost all native grasshopper species prefer dry and warm habitats, the marsh grasshopper prefers moist habitats such as fens and wet meadows. As such habitats can be found as far up as the mountains, the highest occurrences are often well above 2000 m above sea level. Grasshoppers usually draw attention to themselves through their striking song. Not so the marsh grasshopper: it flings both hind legs backwards in a jerky motion and grazes an edge of the wing, making a soft, discreet "zigzag" sound that can only be heard by trained ears.
Monkshood bumblebee
The aconite bumblebee Bombus gerstaeckeri is easily recognizable even to laypeople due to its characteristic colouring (brown-yellow thorax, white abdomen tip) and typical flower visitation. While other bumblebee species choose different flowers for foraging, it collects pollen and nectar exclusively on monkshood. With its almost body-length proboscis of 2.5 cm, it is almost the only bumblebee species able to reach the nectar in the deep-cup aconite flowers. Despite intensive searches, it has only been found in very few places in the park. Due to its rarity, populations of this species are periodically surveyed and monitored in the Landscape Park.