According to a new study, bat-eating spiders are all over the place except for Antarctica.
An extensive bibliographic search was done in order to discover any information available on bat-catching spiders. The search was based mostly on the Thomson-Reuters data base (Web of Science), Google Scholar, Google Books, ProQuest Dissertations & Theses, and Flickr image-hosting website (hosting more than 6 billion images).
Bats are one of the most successful groups of mammals worldwide. There are 1,200 species of bats which accounts for 20 per cent of all mammal species.
Bats are known for having few natural enemies. The most prominent bat enemies mentioned in the scientific literature are owls, hawks, and snakes.
However, the new study has found that web-building spider species that kill and trap bats with the web are more frequent than previously known. Researchers were aware of deaths of bats caught in spiderwebs by chance in the past.
88 per cent of the reported cases of bat catches were due to web-building spiders with giant tropical orb-weaving spiders with a leg-span of 4 to 6 inches (10 to 15 centimeters) seen catching bats in huge, strong orb-webs up to 5 feet (1.5 meters) wide.
The study notes that it is still arguable whether all incidences reported in this paper are real predation attempts or whether some are just deaths by web ensnarement without the active involvement of the spider (non-predation deaths).
The finds were published on online March 13 in the journal PLOS ONE.