Eastern Kingbirds hunting the insect emergence

The air above Suffield Wildlife Management Area shimmers with more than heat. Thousands of delicate wings catch the early summer light as mayflies, caddisflies, and midges rise from the water in synchronized clouds. This is emergence week, when aquatic insects complete their transformation and take to the air in numbers that can darken the sky.

Eastern Kingbirds wait for this moment. Perched on fence posts and dead branches along the wetland edges, they launch themselves into the swirling masses with mechanical precision. Each sortie lasts only seconds. The kingbird darts upward, snaps its bill shut around a mouthful of insects, and returns to its perch to swallow before launching again. Their white tail bands flash like semaphores as they work the emergence.

These insects have spent months or even a full year underwater as nymphs and larvae, breathing through gills, feeding on detritus and algae. Now they must shed their aquatic skins, unfurl new wings, and mate before their brief aerial lives end. Most will live only hours or days as adults. The mayflies are especially ephemeral, their mouthparts so reduced they cannot feed at all. They exist only to reproduce, rising in coordinated swarms that can stretch across miles of water. The caddisflies emerge more gradually, their tent-shaped wings carrying them away from the water to find mates in the surrounding vegetation. The midges, smallest and most numerous, dance in loose columns that pulse and weave like smoke.

For the kingbirds, this abundance means everything. During peak emergence, a single bird can capture hundreds of insects per hour. The protein fuels their own breeding efforts and feeds their nestlings, which are demanding more food as they grow toward fledging. The timing is no accident. Kingbirds nest when aquatic insect emergence peaks, their breeding cycle locked to this brief window of plenty. Other aerial insectivores, tree swallows and bank swallows, work the same emergence from different heights, but the kingbirds own the middle air space, their aggressive nature keeping competitors at bay. They will chase hawks, crows, even eagles that venture too close to their feeding grounds, but they tolerate the smaller swallows that hunt above and below them. The water ripples with the disturbance of more insects breaking the surface, and somewhere overhead, another kingbird launches into the rising swarm.