The little flycatcher, whose portrait graced yesterday's post, and whose daily company I enjoy, chooses to regularly perch on various nearby limbs simply because he's afforded an excellent view of the Cottage Pool. A prime spot because this large pool—ten feet from the window, and constituting my flowing front yard—is located directly below a long, rocky, and thus well-aerated riffle. As such, it's a virtual free-eats food factory…at least if you like dinning on mayflies, caddis flies, and similar aquatic insects.
Most days—especially sunny ones—from midmorning onwards, various "bugs" whose life cycle is closely associated with water, either on or in, began to appear. Sparsely, steadily, and in massive swarms. Mayflies, caddis flies, stoneflies, dobsonflies, alderflies, dragonflies, damselflies—the list is long and, apparently, tasty.
Predators know this, eagerly watching and waiting. When the bugs are few, the feeding action is slow-paced, leisurely. One swoop, catch, gobble at a time. But some insects hatch and leave their watery homes en mass—thousands, even tens of thousands of mayflies or caddis boiling up from the depths, shucking their larval husks as they rise, popping onto the surface where they give their winged, airborne versions a bit of pre-flight drying time, floating a few moments on the river's surface before taking flight. Vulnerable. Available. In quantity!
Shazam! The feeding frenzy begins! Fish rise, slashing at floating insects. Birds wheel and swoop, catching their meals in the air—just above the water, ten feet up, at treetop level, and higher. As the insects rise and fly off, trying to disperse—or sometimes mate before returning to the water to deposit their eggs—the hungry, rapacious birds follow, nabbing at their ranks like starving teenagers at a pizza party. Swallows, flycatchers, swifts, nighthawks, waxwings, along with everything else from robins to sparrows to cardinals and jays. Any bird who likes a good bug from time to time occasionally gets into the melee. I've even watched woodpeckers make a few runs on occasion.
The image at the top of the post is of mostly swallows feeding high above the pool perhaps a half-hour after a recent hatch began. The photo at the bottom shows the density of this same hatch, a few feet above the river's surface, backlit by the setting sun. The middle shot is of the hatching mayflies causing all the fuss.