The silver-haired bat feeds on insects (1) (2) (4), commonly taking flies, beetles, flying ants, termites and moths, although it is an opportunistic hunter that will also eat a wide range of other insect prey (1) (3) (5). It is believed to be one of the slowest flying bats in North America, but is highly manoeuvrable, and typically pursues prey over short distances (1) (2) (3) (4). Foraging commonly takes place along streams and ponds or in small clearings (4), although this species has also been reported to consume insect larvae on trees and even to forage on the ground (1).
Although often regarded as a solitary species, the silver-haired bat may form small ‘maternity colonies’ in spring, and has been reported to come together in groups of both sexes for the autumn migration (1) (2) (4), which takes place from August to October (2) (4). Courtship and mating also occur in the autumn, and most of the bats travel south to hibernate for the winter months (1) (2) (3) (4) (5), although some individuals are also known to hibernate in more northerly locations (1) (5). Female silver-haired bats are believed to migrate further than males (3), and it is possible that some males remain in the winter range throughout the year, with females moving north in April and May to give birth (2) (4) (5).
After mating, the female silver-haired bat is believed to store sperm over winter, delaying fertilisation until the spring. Two young (sometimes one) are normally born between June and July, after a gestation period of 50 to 60 days (1) (2) (3) (4) (5). The female roosts with the head facing upwards during the birth and bends the tail membrane forward to catch the young as it is born (1). The young are weaned after around 36 days and start to fly at about 3 weeks (2) (5). The silver-haired bat may reach sexual maturity after 5 months, and individuals have been recorded living for up to 12 years (2).