As August dawns I begin what I consider to be the official start of fall and winter collision monitoring at the Noble Research Center, and the 10 or so Barn Swallows streaming past as I conducted this morning’s survey reinforced that migration is well under way. On the 19th of this month, I will mark the official 5-year anniversary of near daily monitoring at the NRC. Right now, I am scrambling to get some ABC Bird Tape up on a critical alcove surface for an in-the-field test of that window treatment’s efficacy in reducing collisions.
The spring/summer monitoring just concluded spanned the 153 days of Mar.–Jul. 2014. With some assistance from Scott Loss, we conducted surveys on 122 (80%) of those days or one survey every 1.25 days. I left 6 carcasses in place to estimate removal rates during this period, and the first 5 lasted 1, 5, 6, 3, and 4 days, respectively, before removal (mean = 3.8 days). Thus, my survey rate was well within the bounds of the removal rate and it is unlikely that I missed many fatal collision events. In other words, the total 18 dead birds I found is close to the total number of birds that died at the NRC during this period. This is excluding the outlier Mourning Dove estimated to have died on June 10 that has now been easily discernible and identifiable for 52 days this summer.
One positive note for this period is that (also with Scott’s help while I was away), 5 “trapped” birds were discovered and steered away from the building before they too became casualties.