0000000000097265
AUTHOR
Jurgis Suba
Body weight provides insights into the feeding strategy of swarming bats.
Temperate bat species that hibernate in underground sites are known to visit hibernacula in late summer where they perform an activity known as "swarming". We analysed trends in body mass-to-forearm ratio - the body condition index (BCI) - to investigate whether bats arrive at swarming sites following intensive nocturnal feeding. In a two-year study, Myotis daubentonii, M. brandtii and M. dasycneme were captured by mist-net at one swarming site from late July until early October. In late summer, the BCIs of captured males, females and subadult bats were positively correlated to the time of their capture during the night. In September, adult bats had higher BCIs than in late summer and the B…
Fly-and-Forage Strategy in the Bat Pipistrellus nathusii During Autumn Migration
Populations of Pipistrellus nathusii (Nathusius's bat), an insectivorous aerial-hawking species that breeds in north-eastern Europe, perform long-distance migrations between breeding sites and hibernation areas in central and southern Europe. The feeding strategy of migrating P. nathusii was investigated in Latvia on the east coast of the Baltic Sea, exploring evidence for and against two non-mutually exclusive predictions that i) the bats feed shortly after dusk at highest aerial insect activity and continue to migrate thereafter or ii) apply a ‘fly-and-forage’ strategy and frequently interrupt their migration flight to feed. Echolocation calls and feeding buzzes of P. nathusii were record…