SUCKLING BEHAVIOR IN THE BROWN LONG-EARED BAT (PLECOTUS-AURITUS)

Thirty-two adult female brown long-eared bats were taken into captivit y. Eight individuals gave birth to single young in captivity (known mo ther-young pairs). 10 were lactating when captured (putative mother-yo ung pairs), and the remaining 14 bats were non-reproductive, Bats were maintained in five groups consisting of females from single (n = 3) o r mixed (n = 2) wild roosts. All bats were housed in outdoor, free-fli ght enclosures and fed mainly on free-flying noctuid moths. Bats were individually marked with exclusive codes using black and white plastic split rings. Suckling associations were determined daily (n = 152) fo r a single group of bats containing four known mother-young pairs and five non-reproductive bats. The probability of a bat being attached to the nipple declined from 100% of records at 1-5 days of age to 5% of records at 36-40 days of age. Females were always found suckling their own young. Suckling associations were determined using infra-red sens itive video-recordings of bat behaviour within the roost box. For both known (n = 8) and putative mother-young pairs (n = 10), there were no records of young attached to lactating females other than their own m others (from the same or different wild roosts).