In summer when I walk along the desert washes, I’ll often spook a Lesser Nighthawk. The startled bird lifts silently in strange, buoyant flight, more like a butterfly than a bird.
But then this is a most unusual bird. Nighthawks hunt at dawn and dusk, soaring low across the landscape, scooping up insects. Unfortunate bugs are inhaled from the air and trapped by small hairs that line the gaping mouth.
When not hunting Lesser Nighthawks hide in plain sight, sitting on the ground or sideways on a horizontal tree branch, completely concealed by their cryptic coloring.
Lesser Nighthawks are among the very few birds known to hibernate. They typically migrate south in winter, but they have the ability to slow their heart rates, temperature and respiration to a near stop for days and even weeks to survive. At the other extreme, when the weather is too hot for even resting in the shade, the bird turns into the breeze and open its wide mouth, making a passive cooling system.
Out walking in the early morning I’ve heard a low-pitched sustained trill – the mating call of the male Lesser Nighthawk. It’s eerie and beautiful. The bird also calls with a whinnying laugh.
The female lays her two eggs on the bare ground, and conceals them with her own mottled grey and brown body. She moves the eggs as needed, rolling them to shade or a safer hiding place. Her nestlings are born with eyes open and covered with a fine down. They will walk in a day or two, but won’t fly or feed themselves for several weeks.
Hear the calls of the Lesser Nighthawk: https://www.allaboutbirds.org/guide/Lesser_Nighthawk/sounds