Going to Bat for Bats

Bats can eat up to 1,200 mosquitoes an hour. Often, bats consume their body weight in insects every night, helping keep bug populations in check.

The Nature Conservancy

Many of Vermont’s nine species of bats are in serious trouble, but there are things you can do to help them.

The primary causes of bat decline include white-nose syndrome and human development which result in habitat loss and death. White-nose syndrome – a fungal disease – attacks bats while they are hibernating. It has caused a 95-99% decline in affected populations. That makes providing healthy habitats for bats a top priority.

Five species are threatened or endangered – the Little Brown Bat, Eastern Small-footed Bat, Northern Long-eared Bat, Indiana Bat, and Tri-Colored Bat. On the brighter side, the Big Brown Bat is doing well.

Recently, a colony of Little Brown Bats in Vermont has shown early signs that its numbers may be stabilizing, indicating possible resistance to the fungus. Still, as female bats produce only one pup per year, recovery will take a very long time.

All of Vermont’s bats are insectivores, preying primarily on mosquitoes and moths, as well as on many agricultural and forest pests. They feed only at night during the warmer months, using echolocation to pinpoint bugs.

During the day, bats seek warm, dark, dry, draft-free roosts such as hollow trees, barns, and attics. Some species hibernate in caves over the winter and others fly south.

Given these facts, what can you do? First, you can provide shelter, such as bat boxes in appropriate locations; and second, you can provide food and water by conserving a diverse and healthy habitat.

This summer, the Norwich Conservation Commission has erected bat houses at the Milt Frye Nature Area field, Huntley Meadow, Foley Park, Barrett Park, and Brookmead. The students in the Richmond Middle School wood shop built 11 houses. These seven installed houses will be monitored for bat activity starting next spring. Additional houses will be added anywhere bats have taken up residence.

Installing a bat house begins with the construction, or purchase, of a house certified by Bat Conservation International (BCI).

BCI’s research into bat house design and placement maximizes your chance of success.

The houses must be painted black and kept airtight and dry. Follow instructions closely: spacing of 3⁄4 inch is essential between the slots and scoring on the landing pad and all vertical surfaces inside.

To assure adequate warmth, the houses should be placed facing south, with 8-10 hours of continuous sun, and also within a quarter mile of a pond or other body of water with 8-10 feet of open water surface.

Do not place a bat house on a tree. It will not get enough sun and it will attract predators.

Gardening for bats follows the same goals and principles as gardening for native pollinators and birds. Plant native species, emphasize those plants that support the most insects, replace non-natives with natives, and have a continuous succession of blooms from early spring to late fall.

For bats, you want plants that are open at night – the more fragrant the better.

An excellent resource for native plants that support the most insects is Doug Tallamy’s work on keystone species. His books and his website, provide specific resources for finding plants suitable for our area. The Norwich Conservation Commission has a complete list of keystone species native to the Upper Valley as well as local resources for finding plants or seeds.