May 12th was both one of the best and one of the most grueling birding days of my life.
It was one of the best because Will Russell, Pete Dunne and I had chosen the perfect day and perfect place for a “Big Day Big Stay,” and a morning flight of songbirds passed at a rate of 300 per hour. By day’s end we had seen 139 species, apparently a new North American record for birds seen from a single location in a 24-hour period.
It was the most grueling because when I say “seen,” that’s what I mean. On a normal Big Day, 60 to 70% of the birds are heard, but on the Big Stay, barely 10% were audio identifications. We scanned constantly with both binoculars and scopes, sometimes identifying small birds at long distances, and often faced viewing birds backlit by the sun.
Big Stays are unique, perhaps, in the long-term intensity of scanning, but some other kinds of birding are similar. Hawk-watching is the closest match, perhaps. Sifting flocks of gulls at the local dump can be both tedious and eye-testing, as can working shorebirds on a flat or scanning passing flocks of waterfowl at a seawatch. How can you get on every bird possible without gradually going blind?
Though I didn’t exactly poll my teammates on the subject, I’m sure we each coped with the eye strain in different ways. Pete, for example, was the only one wearing sunglasses, which he often does. Will and I dislike sunglasses for birding, feeling that the lost light and distorted color more than offset any advantages. But certain tactics were common for all three of us, and they might help you, too:
Alternate scanning with binoculars with periods of scanning naked eye. This does two things. First, it gives your eyes a break from the pull of magnification. Second, it gives you the widest field of view possible - the naked eye view - which helps prevent birds from sneaking by.
Learn to scope with both eyes open. This is easiest to do with an angled scope, since the “off” eye is pointed at the uninteresting ground and has little reason to try to take over. Keeping both eyes open minimizes “scope eye;” the unpleasant state that long-term scoping often brings, wherein the left eye and right eye refuse to agree what to focus on and thus, everything looks blurry. Just as alternating between binoculars and naked eye helps, so does alternating between scoping and using binoculars.
Find a way to steady your binoculars. Hand shake, and the resulting unsteady image, will rapidly fatigue your eyes, as they work hard to keep the seemingly moving image in view. I found that a seated position, with elbows resting on knees, kept the binoculars very still. While standing, resting the bins on my scope helped. If there had been a tree or post nearby, I would have leaned against it.
Close your eyes periodically for short periods. Closing your eyes stimulates the tear duct to release moisture, and the closed eyelid keeps that moisture there to do some good.
Vary the distance you scan. For example, I would alternate between scanning a nearby row of trees, a distant marsh, the bay to the horizon line, and the sky.
Wear a brimmed cap. Obviously, this keeps direct sun from your face.
Use sunscreen formulated for athletics. Birding is athletic, after all! Non-greasy sunscreen that stays in place even when wet will stay out of your eyes and off your binocular lenses.
Use dark make-up under your eyes, like pro athletes do. Okay, I confess, none of us tried that - but maybe that would have gotten us to 140 species!