HAT's Community Bat Program is trying to learn more about bats in our region to guide conservation efforts, to enhance habitat through the placement of bat houses, and to help homeowners who choose to evict bat colonies to do so in a way that harms the bats as little as possible.
The Annual Bat Count
With other Community Bat Programs across BC, HAT is helping to coordinate the Annual Bat Count, a citizen science program to annually monitor bat populations in roost sites. Abandoned houses, barns, church steeples – and even currently-occupied structures – can provide a summer home to female bats and their young. Monitoring these “maternity colonies” can give biologists a good idea of how bat populations in an area are doing from year to year. With the occurrence of White-nose Syndrome in North America, monitoring these colonies is more important than ever.
Ideally, the Bat Count includes four counts during the summer - two between June 1 and 21 (before pups can fly) and two more between July 21 and August 15 (when pups are flying and exiting the roost with their mothers). Doing all four bat counts allows us to best compare data from year to year and between sites. However, if you don't have time you can choose your level of participation.
Bat Houses and Habitat Enhancement
In natural settings, bats would roost in wildlife trees. Wildlife trees are dead or dying trees whose hollow middles, flaking bark, and insect-riddled wood provide important habitat to bats, many birds, and other wildlife. Unfortunately, most wildlife trees in the Victoria area have been removed for safety or aesthetic reasons. Bat houses, like bird houses, provide roosts in areas where little natural habitat remains. If you are interested in a bat house for your property, please contact us.
Of course you can always build a bat house yourself. There are two designs that we recommend for Victoria. The most proven design is the 4 Chambered Maternity House. A number of houses with this design have been occupied by bats. It is best installed on the side of a building with as much sun as possible. In order to keep the box warm, it is also a good idea to paint it black. Bat Conservation International has an excellent set of easy to follow plans (pdf).
For open spaces, installing a Rocket-box type house can be much simpler. Built around a central pole, the box is much easier to install if there is no structure to place it on. While it hasn't been proven in the Victoria area to attract bats, it also hasn't been used as often. Painted black and placed in area where it will get lots of direct sunlight, we hope that it will be attractive to bats. The University of Nebraska has an excellent set of plans available (pdf).
Regardless of what plans you choose, if you want your bat house to be successful and safe, there are a few things you can do:
- Keep the box inaccessible to house cats and other predators. Unfortunately, these animals can quickly devastate a colony.
- Make sure the house gets lots of sunlight. In this climate, the more sun the house gets the better.
- Make sure there are no potential flying obstructions near the house. Tree branches and other obstacles will discourage bats from occupying the house.
Many people are deeply uncomfortable with bats in their home or outbuildings. One of our goals is to help people who feel it is necessary to remove bats from their buildings do so in a way that harms the bats as little as possible. HAT will visit homeowners with bat colonies and help them develop a plan to exclude the bats and provide some alternate place for them to roost and raise their young. We will help you identify what time of year to exclude the bats, what renovations will reduce the chances of bats re-occupying your home, and find a place for a bat house for the colony to use. Contact us if you have a colony and would like help with exclusions.
To learn more about bats, HAT uses a bat detector to do acoustic monitoring of bats and their colonies. With bats' rich array of echolocation behaviour and a bat detector we can learn what species are in a colony (often more than 1 species occupies the same site), and learn what times of day and seasons bats are most active. Understanding bat behaviour, for instance when pups first start to fly, is an important part of an effective conservation program. Acoustic monitoring is completely non-invasive - the detector simply listens to the bat echolocation calls.
In partnership with the Ministry of Environment, HAT is collecting guano for DNA analysis. This will provide the most accurate information about which species are in an area and how those species relate to one another. Guano is collected from the ground below the colony and there is no need to interfere with the bats.
HAT is mapping bat colonies so that non-invasive monitoring can be carried out (such as guano collection and acoustic monitoring).