Utilizing Bats to Control Agricultural Pests

PROJECT BACKGROUND
Our farm, which consists of approximately 100 tillable acres, is a diverse operation using sustainable farming practices. While it is currently going through some changes, it will likely maintain a fairly large area for vegetable production (up to 30 acres). The remaining acreage will be rotated between field crops, pasture and hay. Our current vegetable operation utilizes about 10 acres. We also have a community garden program that utilizes about 24 acres.

PROJECT DESCRIPTION AND RESULTS
Project Objective:
Establish a bat colony near agricultural fields, to determine impact on agricultural pest.

Scope of Accomplishment:
Using a design provided by Bat Conservation International, Inc. (BCI) we constructed a bat house that could hold a colony of up to 1,800 bats. The bat house was modified, attaching the posts to a set of skids to allow the house to be moved. It was our hope to establish a colony in the house to determine if the bats would continue to use it if it were slowly moved out to the more open areas near the vegetable fields. We were also planning to provide water troughs for drinking and considered some solar powered lamps to attract insects to assure a steady source of food. This could have the added benefit of attracting some pests away from the vegetable fields.

The house was built by a group of young people from Tree Trust, as part of a job training program.

The house was built in July of 2001, so we did not expect to see it used by bats so late in the season, however, one bat did start to roost in it within a couple of weeks of completion. Hoping to attract bats at brooding time the following spring, the house was moved to another location. It is not certain whether the new location was a poor choice or if the sporadic weather that spring, from very hot early in the spring to an extended extreme cold that lasted into early summer, discouraged use of the house.

About midsummer the house was moved to a new sight near a place where bats were known to roost in a garage building.

At this time a graduate student volunteered to monitor the bat house for a short time to determine if it was being used at all. By physically viewing the house at dusk on a couple of evenings and observing bat droppings on the skid structure on which the house was attached, it was determined that several bats were using the house at least as a roosting area for evening flights. No bats were observed roosting in it during the day.

At that time it was determined that an extension of the grant would be needed to allow the bats another opportunity to move into the house during the following spring brooding season now that they were familiar with the structure. Our intent was to seal off the access to their current roosting area in the garage in a manner that would allow the bats to exit the roost, but at the same time deny them access, in the hopes that they would move over to the bat house sitting very near the area.

It was during the fall of this year that the Wilder Foundation, which owned the farm, made the decision to close down the total farm operation and terminate the employment of all staff, including those involved in this project. For that reason an extension of this project was not requested and the project was incomplete of any substantive conclusions.

OUTREACH
In speaking with a number of farmers there seems to be genuine interest in exploring the concept of this project further.