What species of bats do birds hunt

Habitats

Bats mainly hunt in the air, but they sleep, mate, raise their offspring and hibernate in roosts where they are protected from predators, drafts, moisture and cold. The roosts are so important that bats cannot develop a habitat without them.

1. Hunting grounds

Like insectivorous birds, bats hunt in many different habitats. Depending on the species, forests, karst areas, (shrub) heaths, watercourses, standing water and wetlands, parks and gardens, orchards and even settlements are preferred. Bat species with long, narrow wings - like appropriately equipped bird species - specialize in the free air space above open vegetation, while species with short, broad wings hunt in or between closed vegetation. In addition to the type of vegetation, the climate (i.e. the degree of longitude and the height above sea level) and the accessibility of suitable quarters are decisive for the occurrence of a species.
As night and twilight hunters, bats are much more difficult to spot than birds. If you want to watch them hunting near settlements, you should go to a pond, pond or lake on warm summer evenings and look at the still glowing sky when night falls: Suddenly you can see them fluttering silently and seemingly aimlessly over the water and the bank disappear from the field of vision and a little later come out again from behind a tree.

2. Summer quarters

This term is a bit fuzzy because it combines three functions or types of quarters.

  • Day quarters are searched for on the train to the nursery after the winter break. The animals spend the day here individually or in small groups to go hunting at night.
  • Nurseries are obtained by many females together to give birth and raise their young. During these months the males of many species live alone in their day quarters; in some species (e.g. noctule bat, two-colored bat), however, they form larger groups.
  • Mating roosts are often identical to the day roosts: Here the females meet the males after leaving the nursery roosts to mate.

While local species such as the relatively common pipistrelle bat (Pipistrellus pipistrellus) and bats in southern Europe seek these roosts in close proximity, migrant species in northern and central Europe cover greater distances between them. The train to their winter quarters can even be over 1,000 kilometers.
Bats can suddenly and unexpectedly appear in the apartment as "eerie nightmares" - for example, after a short vacation, hanging from the curtains behind a tilted window. As a rule, these are day quarters that would soon be given up again. On closer inspection, the animals are actually only "incredibly" small and harmless and, if they are not wanted there, can be carefully moved out in the evening.

3. Winter quarters

Roosts are suitable for a bat to hibernate if they meet four conditions:

  1. At the warmest point, the temperature must not drop below 0 ° C - otherwise hibernators can get frostbite or freeze to death. So the cave has to be deep enough.
  2. The relative humidity must be very high - at least 80%, better 90%.
  3. The hanging or sleeping place must be protected from drafts.
  4. The walls and ceiling must be sufficiently rough at the climatically most favorable point so that the claws can find a hold for hanging.

Bat species that originally hibernated in natural caves have long had problems asserting themselves in the north of their range: Many caves were too cold in winter, the few sufficiently deep and therefore frost-proof caves were therefore used by many species and thousands of animals at the same time. Human structures then brought relief for centuries: Mine tunnels, castles and churches, bunkers and wine cellars made it possible to hibernate at safe plus degrees. In old buildings, hibernating bats have been found behind grave slabs and pictures, in wall cracks and holes behind the plaster, between beams and walls, in the roof truss under rafters and in many other places near people. Tree-dwelling bats, which can survive in deep caves of old, mighty trees or crevices in the rock, "conquered" cavities in thick walls and attics, which remain more or less frost-free due to the rising warmth of the house.
This bat-friendly time was interrupted in the 20th century when people began to wall up old tunnels and cellar vaults as sources of danger, demolish or "modernize" old structures (i.e. seal them from the outside) and build new buildings without access to prevent heat loss. At the same time, the ecologically so important ancient giant trees fell victim to an equally "modernized" forestry. Today, great efforts are required to enable heat-loving species in particular to overwinter in our latitudes.

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