Chimney swifts hunting the insect rise
June 5, 2026
Above Concord's neighborhoods and wetlands, the air fills with the chittering calls of chimney swifts. These sickle-winged birds slice through the early summer sky in erratic arcs, their mouths open wide as they collect the season's bounty. The longest days of the year have arrived, and with them, the emergence of countless aquatic insects from streams, ponds, and marshes throughout the region.Chimney swifts never land except to nest and roost. They feed, drink, and even mate on the wing. Their entire lives unfold in three dimensions above us. In early summer, these aerial hunters face their greatest challenge: feeding nestlings tucked inside chimneys and other vertical structures around town. The young birds demand constant provisioning, and parent swifts respond by hunting almost continuously from dawn until dusk.The timing aligns perfectly with one of nature's most reliable food pulses. Mayflies, caddisflies, and other aquatic insects spend months or even years developing underwater as larvae. When water temperatures warm and daylight peaks, they emerge en masse over just a few days or weeks. The insects crawl from streams and ponds, shed their nymphal skins, and take to the air for their brief adult lives. Some mayflies live only hours as winged adults, just long enough to mate and lay eggs. For chimney swifts, this emergence represents a concentrated feast. The birds gather wherever the insects rise thickest. Over the Merrimack River and smaller waterways, swifts wheel and dive through clouds of newly emerged insects. Their gular pouches, expandable throat sacs, allow them to collect dozens of small insects during a single hunting flight before returning to feed their young.The swifts hunt in layers. Some skim low over water surfaces where insects first take wing. Others patrol the middle air where thermal currents carry the insects higher. The highest fliers intercept insects that have dispersed widely from their emergence sites. This vertical partitioning means swifts can exploit the insect emergence at multiple elevations simultaneously. Parent birds make dozens of feeding trips each day. They compress their catch into a compact ball held in their throat pouch, delivering protein-rich meals to nestlings that will double their weight in just weeks. The young swifts must grow quickly. By late summer, they will join the adults in their remarkable migration to South America, spending the winter months in perpetual flight above the Amazon basin.But for now, in these longest days, the focus narrows to the immediate demands of raising young. The adult swifts trace their hunting patterns against the evening sky, their calls echoing off buildings and trees. Each erratic flight path follows the invisible highways of rising insects, the ancient choreography of predator and prey played out in the air above Concord. Listen for their chittering calls overhead, sharp and insistent against the softer sounds of evening.
The frosted elfin's single choice
May 21, 2026
The morning light catches the silver undersides of leaves turning in a warm breeze. Here in this sandy opening among the pines, where the soil stays dry and the sun reaches down unfiltered, a small drama unfolds that most will never see. If you are walking through similar habitat today, pause at the edges where forest meets field. Close your eyes and listen to the quiet rustle of low-growing plants.A frosted elfin butterfly, no larger than your thumbnail, settles on a spike of purple flowers. Her wings are brown-gray above, frosted white below, and she moves with the deliberate care of someone making the most important decision of her life. The flowers belong to sundial lupine, a plant that grows in scattered colonies across this rare habitat. The butterfly tests the plant with her antennae, tapping the stem, the leaves, the developing seed pods. She is searching for the perfect place to lay a single egg.This is not a casual relationship. The frosted elfin caterpillar can survive on sundial lupine alone. No other plant will do. The butterfly evolved alongside this lupine, timing her brief adult life to match the plant's flowering period. When she finds a suitable flower spike, she curls her abdomen forward and deposits one small, pale egg on a flower bud or young seed pod. The caterpillar that emerges will feed on the lupine's flowers and developing seeds through the summer, then pupate in the soil below the plant. Next spring, if all goes well, another frosted elfin will emerge to continue the cycle. The lupine benefits too. The caterpillars eat some flowers and seeds but leave most intact, and the adult butterflies help pollinate the remaining blooms as they move between plants.But sundial lupine is disappearing. The sandy, open habitats it requires are rare in New England, squeezed between expanding forests and human development. The invasive multiflora rose and Japanese barberry that grow here crowd out native plants, changing the soil chemistry and light conditions the lupine needs. Each lost lupine colony means fewer places for frosted elfins to lay their eggs. The butterfly's specialization, once an advantage that allowed it to thrive in a specific niche, now makes it vulnerable. When the lupine goes, the elfin goes with it. The wood thrush calls from the canopy above, the eastern towhee scratches in the leaf litter, but the elfin's world shrinks to the handful of lupine plants that remain. You can see this partnership playing out right now if you know where to look. The lupine's purple flower spikes rise from low rosettes of palmate leaves. The plants grow in small clusters, connected underground by spreading roots. On warm afternoons in late spring, when the sun heats the sandy soil, frosted elfins emerge to mate and search for egg-laying sites. Their flight is low and erratic, easy to mistake for a small moth or skipper. But watch closely and you will see them return again and again to the same lupine plants, testing and choosing with an urgency born of a short adult lifespan and a single chance to get it right.
