Subject: Re: Bat houses - natural pest control

From: [email-masked] (Anatum)
Date: 18 Sep 1994 10:06:01 -0400

In article <[email-masked]>,
[email-masked] (Dan Settles) writes:
I certainly don't mean to knock the use of bat houses, since I think its a
great idea, but do these work for anyone else. 

Hello,
I am a wildlife consultant in the North San Francisco Bay Area. Much of my
work is with winegrowers, specifically habitat enhancement for natural
aerial predators (raptors, bats, insectivorous birds). 
Perhaps a good place to start in obtaining data on successful bat house
usage would be through the BCI survey. I have not seen the results from
the survey at this point.
In my experience, bat houses are effective only when designed for the
species which are present in the area, since details such as size, landing
zones, maternity shelves, etc. are fairly species-specific. 
Man-made bat houses seem to be most successful when they are LARGE - at
least 2 by 3 feet, even larger. They should provide temperature and
humidity characteristics similar to those the bats would prefer when using
a building for a roost. Keep in mind there are many species of bats, and
not all like to use structures. There are cave-dwellers and tree-dwellers
which won't use structures, especially small man-made "bat houses".
There has been good success in some states with bat houses. Usually these
are large structures capable of housing several hundred bats. In Oregon,
the only successful project I have heard about is with little brown bats
(the common name of the species). This species seems easier to attract to
bat houses in many areas. There are others species that use bat houses, as
well.
I am waiting for the current results of the BCI curvey. Until then, I am
unenthusiastic about the use of small, store-bought bat houses. Because I
know the beneficial aspects of bats for agriculture, I am very interested
in finding and developing the most effective bat houses.
Good luck,
Greg Tatarian
Wildlife Research Associates
[email-masked]