By Christopher B. Daly
Recently, I had the pleasure of sitting in my backyard near Boston on a warm summer evening. I could hear the screech owls calling, as they have been doing every night this summer. I have heard them before in the yard, but always as migrants, passing through in the fall or spring. This year, I could pretty clearly make out a family group, based on the numbers and the calls for food from the fledglings.
This night was the hottest of the season so far, and I noticed something different: air conditioners were going, in our house and in the house next door. I found the noise annoying, but then I got to wondering how it affects the owls. After all, they need to use their ears to hunt. According to a wonderful book I am reading, Bird Sense, by Tim Birkhead, owls use their famously large, front-facing eyes mainly to navigate in flight to the vicinity of their prey. The “final approach” to the target is guided by hearing, through the owls’ equally famous ears.
But what happens when two air conditioners are roaring all night? Does the sound level interfere with hunting? Do the motors drown out the faint – but vital — scritch-scratchings in the undergrowth that the owls depend on?
I don’t know, but I do know that on that hot night, the owls moved off and went hunting elsewhere. Presumably somewhere quieter.