Habitat Acquisition Trust's Community Bat Program bat counts began in 2013. This means we can look back a few years now at specific roosts and see a snapshot of the bat population.
While this is a small sample size, and not yet a long trajectory to look at to draw conclusions, it is very interesting and will be useful as a growing baseline of data for bat conservation. This data also contributes to the province wide data on bat roosts collected through the BC Community Bat Program.
We hope all of you bat counters are proud to be part of moving our knowledge of and protection for local bats forward.
The larger scale volunteer led bat counts with HAT began in 2015. Looking across the major bat counts for the 7 sites we looked at from 2015 – 2017, the total number of bats counted increased from 2015 to 2016, then decreased from 2015 and 2016 numbers in 2017. Since this is such a small sample size and across a very short period of time, it’s tough to say if this is any kind of trend. So we will just have to keep collecting data to learn more.
Of the 9 sites surveyed in both 2016 and 2017, 5 actually had their highest numbers of bats recorded compared to previous years, with 8 still higher in 2017 than their lowest year’s count number. Between 2016 and 2017, of all 9 sites 6 had an increased number of bats and 3 had a decreased number of bats counted. So it seems to be generally that the data is simply reflecting regular fluctuations and no clear trend is observable yet.
2 of the sites where there were bats counted in an original roosting structure and bats had colonized a newly placed bat box, the overrall number of bats increased. This may show some promise for adding bat boxes to provide more habitat for colonies to grow.
For the two bat colony sites that we have data for each year from 2013 – 2017, their bat count numbers went down in 2014, up in 2015 and 2016, and dipped again from 2015-2016 levels in 2017, but still remain above their lowest numbers.