Ruby-throated hummingbirds arrive at early flowers

The air above the Dover Community Trail holds a different quality now. A faint whirring cuts through the morning stillness, then stops. Ruby-throated hummingbirds have returned to southern New Hampshire, their arrival timed to the opening of the first reliable nectar sources and the emergence of the tiny insects they need to fuel their breeding season.

A male ruby-throated hummingbird weighs less than a nickel, yet he has just completed a journey of over five hundred miles from wintering grounds in Central America. His throat flashes crimson as he hovers at the small white flowers of Canada mayflower, his bill probing for nectar while his tongue flicks out forty times per second. But nectar alone cannot sustain him. Hummingbirds require protein for muscle maintenance and egg production, and they find it in gnats, aphids, and spider silk gathered from webs stretched between branches.

The timing matters. Northern red oaks along the trail are releasing clouds of pollen now, their catkins dangling in the warming air. This pollen feeds countless small insects, the same insects the hummingbirds hunt. Gnats cluster around the oak flowers. Aphids work the tender new maple leaves. Small spiders rebuild their webs each morning, and the hummingbirds harvest both the trapped insects and the silk itself, using the protein-rich strands to construct nests no larger than a golf ball. The pink lady's slipper orchids, emerging now from the forest floor, attract small bees and flies that also feed the returning birds. Each flower that opens extends the foraging opportunities for creatures that measure their energy expenditure in heartbeats per minute.

The male hummingbird establishes a territory around these resources, defending a circuit of flowers and insect-rich areas with fierce precision. He dive-bombs intruders, his wings producing different sounds for different threats. Against other hummingbirds, his wingbeats create a sharp chittering. Against larger birds, he produces a lower buzz. His mate, when she arrives, will need these defended resources to fuel the production of two eggs, each the size of a navy bean. She will incubate them for two weeks, leaving only briefly to feed, then spend another three weeks bringing insects to the nestlings every ten to fifteen minutes throughout the daylight hours. The forest's insect abundance in late spring makes this intensive schedule possible.

Listen now. That high, sharp chip from somewhere in the canopy above might be a hummingbird calling from his perch between foraging runs. The sound carries farther than you might expect from such a small bird. If you are still, if the morning light catches just right, you might see the flash of green and red as he moves between the oak flowers and the understory blooms, his presence proof that the forest's smallest partnerships have resumed their ancient rhythm.