Monitoring Bat Colonies

bat houses on a barn

Vermont’s bats are in trouble and we need your help finding and counting colonies of bats living in buildings.

Monitoring summer bat activity

Female little brown and big brown bats congregate in groups in the spring through summer to give birth and rear their young. Your help monitoring summer bat activity around the state will let us make informed decisions about the welfare and long-term conservation of these important mammals.

How do I get involved?

We make it easy. We supply a detailed instruction sheet and all the necessary forms to fill out. So if you are interested, download the instructions and forms and get ready to start your counts.

What is the commitment level?

  • Bat Reporter - Conduct at least one count of the number of bats exiting a roost a night (emergence counts) between May 15 and July 31. If conducting only one count, try to conduct in mid-July when the colony should be most stable.

  • Bat Tracker - Conduct at least one (preferably 2) emergence counts of a roost before most pups begin flying. Conduct between June 3 and June 23. And at least one (preferably 2) emergence counts after most pups begin flying. Conduct between July 8 and July 28.

  • Bat Enthusiast - Conduct at least one emergence count of a roost every 2 weeks (preferably every week) from: May 15 through July 31.

How will monitoring bat colonies help?

Monitoring summer bat activity will help us gather baseline information on summer bat colonies. It will also let us evaluate the impact of White-Nose Syndrome (WNS) on summer bat colonies by:

  • Identifying the location and evaluating the approximate size of bat maternity roosts by counting the number of bats exiting the roost at night (emergence counts).

  • Determining where more monitoring is needed by comparing the bat counts before the young bats (pups) can fly (pre-volant counts) and after the pups start flying (post-volant counts).

See also:

Contact Us

Vermont Department of Fish & Wildlife
Commissioner Louis Porter

1 National Life Drive
Fish & Wildlife LogoDewey Building
Montpelier, VT 05620-3208

Staff Directory

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