Lesser Nighthawks on the Grasslands

Arid scrublands.  Desert washes.  Dry grasslands.  

Perhaps these words don't conjure up images of idyllic natural beauty for most people, but for one very special bird, these marginalized habitats are prime.  This bird is just one of several reasons why I love deserts and desert-like places, and this special bird, I think, has a special message for all of us.

A few days ago, I encountered a pair of these incredible nocturnal birds not too long after sunrise on the grasslands, and was delighted to snap a few photos that capture this species' remarkable beauty.  

As residents of the arid Southwestern United States, Lesser Nighthawks are perfectly equipped to handle life in hot, dry climates.  Nocturnal (active at night) and crepuscular (active at dawn and dusk) behavior is a classic example of how many species have been designed to handle the heat, as flying during the cooler, darker hours prevents them from overheating while hunting on the wing.  It also minimizes moisture loss in a habitat where water is often scarce.  In order to navigate in the dark, the large eyes of nighthawks are equipped with tapeta lucida, mirror-like structures at the back of each eye that reflect additional light back to the retina, allowing for increased night vision.  This structure is present in other nightjars (like whip-poor-wills) and owls, and in nocturnal mammals as well.  (The tapetum lucidum is responsible for the "eyeshine" we see when our headlights shine into the eyes of, say, a cat or coyote.)

Without this adaptation for night vision, our best chance at seeing nighthawks in flight is around dawn or dusk, when these graceful birds hunt most actively.  In flight, Lesser Nighthawks exhibit a distinctively buoyant, fluttering flight style as they course through the air on long, thin wings.  As aerial insectivores, nighthawks "hawk" insects on the wing, often flying low to the ground in their open habitats.  Flying with their unexpectedly large trap-like mouths wide open, nighthawks capture any flying insects they happen across.  Fine hairs (or hair-like structures) line the mouth, making it more difficult for prey to escape before the wide mouth is snapped shut.  

Hidden in plain sight: Near the center of this photo, a Lesser Nighthawk is roosting on a patch of rocky ground within its arid grassland habitat.

Lesser Nighthawks are well-suited to their dry, rocky habitat.  These photos capture just one of their many amazing traits: perfectly camouflaged plumage.  The nighthawk's ability to blend into its open habitat allows it to spend the hottest daylight hours sitting entirely motionless, avoiding detection by predators and conserving energy at the same time.  This cryptic coloring is also critical for the nighthawk's nesting strategy, which is... no nest at all!  In arid habitats often devoid of much nesting material, female Lesser Nighthawks lay their eggs on the bare ground, often in gravelly areas where the eggs blend in beautifully with the surrounding pebbles.  Nesting nighthawks remain resolutely on their nests, even as predators approach, relying on their statue-like stillness and amazing camouflage to hide them from unfriendly eyes.

In order to deal with the extreme high temperatures of their desert habitats, Lesser Nighthawks regularly position themselves so they are facing away from the sun and into the breeze.  Thus situated, they open their large mouths wide, allowing air to pass over the surfaces of their mouth and produce a cooling effect (like dogs panting).  But desert habitats are not only hot, but cold as well.  When air temperatures drop significantly, Lesser Nighthawks handle this change in temperature by entering into a state of torpor, a period of inactivity where their metabolism slows down and vital functions operate at a bare minimum.  (Hummingbirds also enter into a state of torpor to survive short periods of cold weather.)

The way I see it, the physiology and ecology of Lesser Nighthawks is just one more testament to the perfectly orchestrated, intricate design of the natural world by our Creator God.  From beautifully cryptic coloring, to brilliant strategies for keeping cool in the desert heat, Lesser Nighthawks point to a Maker who is both  infinitely wise and unimaginably loving toward all he has made.  

Even in the most inhospitable habitats, He makes life thrive.