Silver-haired Bat (Lasionycteris noctivagans)

Description
Silver-haired Bat

Size

  • Silver-haired bats are notable for their size — they have a wingspan up to 30 centimetres (12 inches).

Appearance

  • Distinguishing characteristics for this species include:
    • Colour — black wing membranes and dark, silver-tipped hair
    • Flight pattern — slow and leisurely, often close to the ground
Distribution
  • Though widely distributed in North America, the silver-haired bat is most abundant in the northern Rockies.
  • Males and females appear to use separate ranges during the summer but apparently winter together in the southern United States.
  • They are strong fliers and some migrate seasonally from Arizona to northern Alberta.
Natural History

Habitat

  • The silver-haired bat is a non-colonial woodland bat, and is rarely found in buildings.
  • Silver-haired bats use tree roosts during the summer. They may be found as individuals or in small groups under bark, in abandoned bird's nests, in hollow trees, or hanging upside down among the leaves throughout the forests in central Alberta.
  • During the winter, they do not stay in Alberta but rather hibernate under the bark of trees, in rock crevices, and, occasionally, in buildings in the southwest United States.
  • During migration, the bats are most conspicuous as they often use temporary daily roosts in such locations as:
    • open sheds and garages
    • on piles of lumber, railroad ties, or fence posts
  • The specific location of the summer and winter roosts is unknown.

When Active

  • They appear to be present in southern Alberta only during the spring and fall migrations (April to July, August to October, respectively).
  • Males do not appear to migrate and, thus, records in Alberta include only adult females during the spring, and females and juveniles during the fall.
Reproduction and Growth

Breeding Behaviour

  • Litter size is two young per female.
Conservation and Management

Status

The silver-haired bat is classified as Sensitive in the current General Status of Alberta Wild Species report. See:

Issues

  • This species experiences mortality at current and potential wind energy projects.
  • Owing to their solitary nature and avoidance of humans, little is known about silver-haired bats in Alberta. As a result, there is a lack of population information for this species.

 

Page Information

Updated: Apr 27, 2009