Technorati Tags: nighthawks,animals,wildlife

One evening in early May, I set out on a walk along the irrigation ditch at dusk. As I turned the corner onto the ditch road, I saw a cloud of birds flying back and forth, skimming low over the water, fluttering up over the road, then turning and flying back down the ditch like swimmers executing graceful laps.

I walked closer. Undisturbed by my presence, dozens of birds navigated the crowded air over the ditch, looping around each other, tilting as they turned, never colliding. The birds were mottled brown all over, with a wide, off-white wingbar near the pointed end of each long, crescent-shaped wing.

These evening flyers are lesser nighthawks, migrants that winter as far south as northern Chile and summer as far north as Colorado. Lesser nighthawks are members of an odd family of birds: goatsuckers, so named for their imagined tendency to suck the milk from goat¹s teats at night.

Lesser nighthawks and other goatsuckers are, indeed, nocturnal. However, their curious gaping mouth with its edging of stiff, bristle-like hairs is designed to scoop up flying insects at night, not to suck goat¹s milk.

By day, lesser nighthawks and other goatsuckers rest on limbs of trees or shrubs or on the ground, holding their body parallel to their resting place so that their mottled brown plumage renders them nearly invisible.

Lesser nighthawks arrive in the southern Southwest around mid-May. Unlike their larger cousins, common nighthawks, who summer in the mountains, lesser nighthawks stick to the lower elevations: from deserts to dry foothills grasslands. They live in towns and around farms, as wells as in the open desert.

Like other goatsuckers, lesser nighthawks do not build a nest. Instead, they lay their two eggs right on the ground, or on a flat gravel roof. Just as the parents’ plumage hides them at rest, so too the eggs, colored pale gray or off-white and spotted with pastel lilac, tan, or gray, disappear against the soil.

Because nesting right on the ground leaves the eggs vulnerable to all sorts of hungry predators, including prowling cats, lesser nighthawks’ nest period is short: the eggs hatch in just two-and-a-half weeks, and the young, born downy and with their eyes open, can fly three weeks after hatching. Soon they are hunting with their parents, swooping close the ground at night to catch beetles, moths, grasshoppers, winged ants, and other insects.

As I walked the ditch in the gathering darkness that May evening, I heard low whinnying sounds, like the trilling of toads. It was the lesser nighthawks, calling to each other as they wove back and forth over the ditch.

The cloud of nighthawks that crowded the air over the ditch that night have moved on, headed farther north for the summer. Only a handful remain, enough to delight me on my nighttime walks.