It’s not just anglers who follow emerging mayflies. The drama plays to appreciative audiences above and below the water. Hatching nymphs rise from dark, watery depths up to the wide blue sky, a glorious curtain call and tolling dinner bell.
By May, the tree swallows – a troupe of aerial acrobats – wheel, dip, and tumble while hawking insects over the river. Beaks dimple glassy water. They rise and fall in an acrobatic synchronized feeding ballet, alternately showing iridescent green backs and snow-white breasts, like two-toned cottonwood leaves blown over the river from surrounding woods.
Unseen, pink-flanked rainbow trout and bejeweled speckled brook trout rise in a mirror image choreography. Trout sip struggling mayflies at the water’s surface. Concentric rings dimple quiet pools. Audible tail splashes break the mirrored surface as trout snatch nymphs and roll down to dark depths. Where waters run clear, witness the flash of fins or bellies as trout troll through nymphs rising like champagne bubbles.
Rivers run high and cold in spring. Mayflies emerge, struggle upward, fly, breed, and die. The fluttering horde surrounds me as I hike in the last light of day. Small price to pay for the performance I’ve witnessed.
Insect protein forms the broad base of the food pyramid. All wildlife ultimately depend on diverse insect populations. It’s the reason why millions of colorful, neo-tropical songbirds hazard the risks of migration to northern latitudes. They’d stay year-round if insects remained as plentiful.