(Lasionycteris noctivagans). Patient Number 22-995 and 22-996.
Date of admission: July 12, 2022.
Reason for admission: Born in care.
Silver-haired Bats are a medium-sized, solitary, tree-roosting bat species. They can live up to 12 years and weigh 8-12 grams. Their scientific name can translate to “night wandering shaggy bat”. They have dark brown-black hairs tipped with silver; this gives them the appearance of looking frosted. These bats have short, hairless, rounded ears, faces, necks, and wings. They also have a cute slightly upturned snout. Adult males and females look alike.
Silver-haired bats are insectivores, they have been found to eat a large variety of bugs. They feed mid-flight and occasionally on the ground. Some predators of the silver-haired bat include skunks, owls, cats, and raccoons.
This species of bat is most common in the United States and in southern Canada. Silver-haired bats are found in boreal, coniferous, and deciduous forests close to bodies of water. Deforestation is a big threat to this bat species and could affect their status in the near future.
They hibernate in small tree hollows, buildings, rock crevices, wood piles, and cliff faces or under tree bark. It may be interesting to know that some populations of silver-haired bats migrate while others don’t. Western populations leave their winter hibernating locations and migrate both east and north. Eastern populations only move north and populations in British Columbia may not migrate at all. Silver-haired bats are also one of the slowest flying bats in North America.
Silver-haired bats breed once a year during fall migration. The males and females form a swarm during migration to reproduce. The sexes typically do not commingle during the rest of the year. Females store sperm through the winter, awaiting spring to ovulate, and become pregnant in late April or May. They then form maternity colonies in tree cavities or hollows. Gestation lasts approximately 50 to 60 days. One or two pups are born blind and deaf with folded ears and no fur, in late June and early July. They are nursed for 36 days and will weigh 1.4 to 2.3 grams at birth. On average, Silver-haired bat pups take 152 days to reach maturity, but only 36 days to become independent.
Our silver-haired bat pups were born in care on July 12. They were found just as their mother was about to be released. Their mother was brought into care after being found in Carstairs on the ground unable to fly due to cold weather. She was admitted in May and was pregnant then, or become pregnant in care. The pups are doing very well in care, and we are working hard to make sure they will be big and strong before they are released. Thank you for your support of this bat family in need!