Going Batty

International Bat Week, a global celebration of the world's most misunderstood mammal, fittingly comes to a close tomorrow on Halloween. To celebrate, let's take a trip down memory lane to that time five years ago when I helped with a bat colony count. It was late summer in 2017. I was just a few weeks away from leaving the Northwest and returning to my native Pennsylvania. I was invited to a pot luck for volunteers at Northwest Trek, a wildlife park in Eatonville, WA. I'd worked with them doing amphibian egg mass surveys for the state and nature mapping for Nisqually Land Trust. There was also a bat colony count happening that night, and I was asked if I would like to join. Of course I said yes. After white nose syndrome was detected in Washington, the state fish and wildlife service wanted to colony counts to establish a baseline population for monitoring purposes. Having worked on other conservation projects with Northwest Trek it was only natural that they would ask them to partner up again. And it was a no-brainer for me to get in on the action. After eating, we took an extended afterhours tram ride through the free roaming area to see the deer, elk, bison, moose, mountain goats, and bighorn sheep who don't know they're lving in captivity. There's nothing wrong with a little extra time hanging out with our animal friends. Afterwards, we returned to the park entrance. I was supposed to monitor the comings and goings at a bat box inside the park just inside the entrance. All I had to do was count how bats flew out and how many flew in, until I couldn't see anymore. Ins and outs, then subtract and the difference is my count. Very simple. But the bats had other plans for the night. Before we even got inside we could hear bats moving around inside the roof of the entrance. I never made it in. Instead, I stood outside the entrance counting bats. I watched as a little bat would drop down from the roof and gain altitude as it moved towards me. I only ducked once or twice. It was just instinct. I knew they wouldn't hit me. I figured with their echolocation they could tell where I was long before I saw them. I could hear theirs wings flapping and feel the breeze as they zipped past my head. At the end of the night, all the participants gathered to turn in their tally sheets. The counting station at the entrance, which wasn't on the list at the beginning, and was almost an afterthought, turned out to have the highest count of the night. I don't remember how many bats we counted collectively, or what my total was. It was a great night and I hope we collected important data. I'm forever thankful I was able to be a part of it.

Firefly Watch 2022

The 2022 season of Firefly Watch was the most disappointing so far. There was a dramatic decrease in the number of flashes counted from 2021, which was a decrease from the previous season. Run by Mass Audubon, Firefly Watch monitors populations of fireflies nationwide, using citizen science observations. Observation protocols are simple. Count how many flashes you see in three separate ten second periods. I space mine ten minutes apart to get varying levels of darkness, starting just before sunset. We also record the flash pattern (single, double, or triple flash for instance), start and end times, wind, precipitation, and temperature. For good measure, I also record the colors of the flashes. I start at the end of May and depending on how long I keep seeing fireflies, I go until late August or early September. I use the same location every year to track the same population, and try to stick to the same dates every year. This year the dates for my second observation of the week were a day later than last year. I end the season when I go two consecutive observations with no fireflies. The latest I ended was September 26 in 2018. This year I ended on August 24, the first time I didn't make it into September. The last firefly I saw was August 7, so I actually went beyond the two night standard. 2022 saw a decrease of 94 flashes from 2021, nearly a 16% drop. That's close to 30% fewer than 2020, the highest count so far. The charts below show the population trends. Chart 1 shows each year's counts by date and how the number of flashes observed changes within the season. Chart 2 shows each year's total counts side by side.

While I could use rainy nights in 2021 as a partial explanation for the decreased count, I only had rain during one or two observations this year. This summer was abnormaly dry, but not quite a drought. Not enough rain could be a possible cause. Other factors include light pollution, although the amount of light is unchanged year to year, and pesticide use, but I have no way to measure who is using what pesiticides in the neighborhood. One final explanation is that the neighbors cleared some vegetation from their small woodlot in the back yard. I'll continue monitoring and hopefully the negative trend will reverse itself.