To Bat or not to Bat House
Good Day! Myself and a few neighbors live in a neighborhood that backs up to a large wetland and ultimately, river. We suspect it’s this situation that allows our mosquito population to be horrendous. If you aren’t willing to douse yourself in Deet, there are many times you can’t be outside of your house. We were thinking a couple of bat houses could really help our situation. I know they aren’t always successfully inhabited but after 12 years of trying other solutions and getting nowhere, we’d really like to use our backyard and are desperate. We were aware of the rabies risk that largely seems to come with approaching a sick or dead bat, but just learned of the dangers of guano. The areas we intended to place the bat houses would be so high and out of the way that we had no intention of creating any kind of poop trap because we’d never clean them out. However, hearing that guano is dangerous makes me wrinkle my forehead because we also have heard it’s great for the garden and have never heard cautions about applying it as a fertilizer. Can someone provide me with the real, local associated risks with installing a bat house? We’re weighing the risks of histoplasmosis over those of West Nile, rabies over Zika, etc. Can you help? Thanks!
Bats can be excellent helpers in managing flying insects! http://www.dfw.state.or.us/wildlife/living_with/docs/bats.pdf
Bat Conservation International offers some great guidelines to help you find the optimal site and mounting for your bat houses: http://www.batcon.org/resources/getting-involved/bat-houses/install
It's good to keep potential conflicts such as disease risk in mind. However, although bats do come up with rabies occasionally in our area, it's a relatively rare risk. Avoid direct contact (including by pets!) with any bat that is down, behaving oddly such as flying during the day or deliberately flying at humans, or exhibiting other troubling signs. Reporting to your District biologist with the OR Dept of Fish and Wildlife (and County Health if rabies is suspected) is a good idea - they may ask you to (very carefully) collect the bat for testing. Histoplasmosis and other disorders from inhalation of body products become a problem if the guano is collecting in enclosed spaces and in large quantities -- attics, caves, etc. Having a bat house or two outdoors won't create that kind of risk, and you might eventually have enough guano below it to add some to the garden!
Overall, I'd say that trying out a bat house or two could be a good idea that would benefit both you and the bats!