That's very interesting; they're lucky to have so many bats in that area. I've been wondering what has happened to the bats around here. When we moved to the NW part of Burnaby more than 40 years ago, bats weren't numerous; but we would see them a few times each summer. For the last 10 or 15 years, I haven't seen a single bat.
There are still bats here, but very few swallows anymore. Was wondering if it might be associated with mosquito control and the use of Malathion.