Discovered bird-eating bat migrating during the night

The blood sample of the largest bat in Europe shows that it seems to have hunted birds flying at night. If so, they are the only species known to do this so far.

Nearly 5 billion birds fly over the Mediterranean Sea each year, mostly at night. Although more than 90% of them weigh on average less than 20 grams, their total weight can be up to more than 100,000 tons - a source of desirable food for carnivores.

However, no animal known to hunt birds when they are flying in the night. Eagles hunt along the Mediterranean coast only during the day, while owls and some other tropical bat species eat terrestrial vertebrates or on other surfaces at night.

In 2001, biologist Carlos Ibáñez at Doñana Biological Station in Seville, Spain and his colleagues discovered evidence that the extremely rare giant bat Nyctalus lasiopterus seemed to eat bird meat, based on the huge amount of bird feathers in the 14,000 samples of their droppings. This amount of bird feathers peaks in spring and autumn - also the season when birds migrate.

Giant bat Nyctalus lasiopterus (Photo: msu.ru)

Recently, bat expert Ana Popa-Lisseanu and colleagues provided strong evidence of this meat-eating habit. That's high levels of carbon and nitrogen isotopes in bat blood - reflecting their menu.

They found blood in the bird diet in spring, autumn and insect diets in the summer. In winter, they sleep in the cave.

T.An