Common Nighthawk | Tiny Bill, Cavernous Mouth

The first and only time I ever saw a common nighthawk was one day in early June of this year. I saw a bird perched on a limb of a dead snag, but didn't think too much of it. From a distance, it just looked like a morning dove at rest, fluffed up with its neck retracted. I almost moved on, but then thought I'd go ahead and give it a look through the camera lens. I'm so glad I did, as what I discovered wasn't a puffed up dove, but a bird I had never seen before. This was a fantastic discovery. I later identified it as the common nighthawk. Ever since then, I have been so intrigued by these birds and eager to see them again. Their name, common nighthawk, is quite misleading. This bird isn't all that common. It isn't nocturnal, and it isn't a hawk. It's not even in the hawk family. So what's the deal with its name? Common nighthawks are a type of North American nightshar in the family known as Capramulgidae. Capramulgis is Latin for goat sucker. In ancient folklore, it was believed that these birds would suck the milk from goats. But no, they don't do that. Their Latin name is Cordyles minor, which loosely translates to moving about in the evening, and minor meaning small. They have also earned the nicknames bug eater because they eat insects and bull bat for their erratic bat-like flight. So how did the hawk part of its name come about? Apparently, the name nighthawk was a local name in England for the European nightshar. Its use in the Americas for the Cordyles genera was first recorded in 1778. Perhaps the most distinguishing characteristic of the common nighthawk is its tiny bill. It has a large head, a thick neck, and a stocky body. Its wings are long and narrow with a white band towards the tip. The tail is slightly notched or forked. Males have white feathers on the throat and at the end of the tail, whereas females do not. The bird that most closely resembles the common nighthawk is the lesser nighthawk. While nearly identical in appearance, the lesser nighthawk is slightly smaller, and the white wing bar is more towards the end of the wing than it is on the common nighthawk. This is quite subtle, however. I think the best clues to differentiate between the two are their habitat range and vocalizations. The breeding season range for the common nighthawk is most of Canada and the US, whereas the lesser nighthawk is localized to a small portion of the southwestern United States and parts of Mexico. Let's take a listen to their vocalizations. The common nighthawk's call is described as a nasal peint sound. Now listen to the lesser nighthawk's call, which is a sustained toad-like trill. That's quite a big difference, isn't it? The eastern whitporwill and common porwill inhabit the eastern and western halves of the United States, respectively. They are strictly nocturnal, whereas the common nighthawk is crepuscular, or active at dawn and dusk. Here's the sound of the eastern whitporwill. And now the sound of the common porwill. Despite the subtle differences in color and patterning, the porwills have rictal bristles, whereas the nighthawks do not. Rictal bristles are the stiff, modified feathers that look like whiskers around the bill that allow the bird to feel insect prey in the darkness. And lastly, the chuckwill's widow, who inhabits the southeastern United States. While they do have a little bit of white on the throat, they lack the white wing bars seen on the common nighthawk. Let's take a listen. If you're thinking that some of the names for these last few birds are a little strange, well, I had that thought too. The names describe their call, which is a handy way to keep them all straight when doing bird identification in the field. Take a look at all of these pictures. Besides the bird itself, what is the common denominator? In each image, the bird orients its body lengthwise to whatever it is perched on. One of their key defensive strategies is to hide in plain sight using their cryptic coloration and stillness. Whether it's a branch, a sign, wire cable, fence post, or a metal railing, most of the time, this is how they position their body, regardless if it blends in with that structure or not. They have even been seen roosting lengthwise along the stripe on a road. While clearly dangerous, it's still impressive how much body awareness they have in relation to their environment. This isn't the case 100% of the time, but it seems to be the majority. When sitting on the ground, they can be very hard to find as their camouflage allows them to blend in seamlessly with dirt, gravel, or leaf litter. Their legs are very short and their feet are small and placed farther back on their bodies, so they are not the most agile when it comes to walking. They are less often seen standing erect and are more often found looking hunkered down as if planted down on their perch in a resting state. I mentioned earlier that one of their defining characteristics is their tiny bill. If your food is flying and you're catching it while you are also in the air, you don't need a strong hefty bill to catch your next meal. What you need is a cavernous mouth to scoop up insects in midair, and the mouth of the common nighthawk does not disappoint. The gape is exceedingly wide, enough to give any insect a run for its money. It's like a feathered pac-man patrolling the skies and providing pest control. The other thing you need is narrow pointed wings. This contributes to their erratic, buoyant, maneuverable flight, making them formidable insectivores. They spend considerable time on the wing, swerving, lapping, stalling, and gliding to catch prey. In urban or suburban settings, they take advantage of the insects swarming around streetlights, stadiums, or brightly lit yards. They eat flying insects almost exclusively, foraging during dawn and dusk and rarely ever at night. Occasionally, they will feed during the day, particularly when it is overcast or before a storm. Since their preference is to forage in low light, it makes one wonder, how in the world are they able to see insects in such conditions? How are they able to see something potentially as small as a mosquito or a fly in dim light? Well, nature equipped them with large eyes and the ability to dilate their pupils on command, allowing them to distinguish among prey while flying. But there's much more to their eyes than just that. Their eyes contain a membrane known as the tapetum lucidum. This is a layer of tissue that is located between the lens and the retina and acts like a mirror. It reflects light back to the retina, increasing the amount of light available to the photoreceptors, thus improving the bird's ability to see in these conditions. The tapetum lucidum is iridescent and is what is responsible for creating eye shine. When light is shown into the eye, the pupil appears to glow. Depending on the angle of the light, the eyes can appear a variety of different colors. They aren't the only birds who have this. Owls also have the tapetum lucidum and mammals such as dogs, cats, raccoons and many other creatures that are nocturnal or active in low light. Another unique characteristic of the common nighthawk is their courtship display. To attract a mate, the male takes to the air, showing off his aerial prowess. While giving his characteristic peat call, at some point, he drives straight down, plummeting until he's only about two meters from the ground and then rises up again. It looks as if he's going to crash, but he isn't. It's all just part of his display. Here's what this looks like. Listen for the sound created when he dives, beginning at around the 13 second mark. It's a little bit faint, so listen closely. Let's listen one more time with a different clip, audio only. The sound created from the dive is referred to as the booming display. It doesn't sound like something that would come out of a bird, does it? It sounds more like the whirring of a truck passing you by on the highway. The sound isn't coming from the vocal cords, but from air rushing through their primary wing feathers after a sudden downward flexing of the wings during the dive. Common nighthawks nest in a variety of environments, such as open fields, gravel beaches, rock ledges, wetlands, grasslands and gravel roofs of houses or buildings. They don't build nests, but lay their eggs directly on the ground out in the open. They lay two pale gray, heavily speckled eggs, which are brilliantly camouflaged into their environment, just like the birds themselves are. The female does most of the incubating, occasionally leaving the nest unattended to hunt for insects. The chicks hatch after about 18 days and are fed regurgitated insects by both the male and female. They defend their nest by hissing and wing beating to scare off intruders. They may also feign injury, flopping and flailing about with one or both wings extended, drawing the intruder towards them and away from the nest. Sometimes the male will use the dive and boom display to drive off any threats, whether it be avian, animal or human. As you can imagine, nesting on the ground makes them particularly susceptible to predators such as domestic cats, dogs, coyotes, owls, falcons, skunks, snakes and raccoons, to name a few. The chicks take their first flight at 18 days old. By 30 days they are flying proficiently, at which point they leave their parents. At about 50 days they are fully independent, ready to join the flock and migrate south. Common nighthawks have one of the longest migrations of North American birds, with a trip totaling 1,600 to 4,200 miles. They are the first to leave in the fall and the last to arrive in the spring. For those who breed in higher latitudes, they begin their southward migration as early as August. They return in early May or as late as June, depending on how far north they travel to breed. They travel in large flocks during the day and night, frequently descending upon wetlands or grassland fields to hunt for insects. I really feel a fondness for these incredible birds and hope that this helped you develop an appreciation for them as well. What was the most interesting fact that stood out to you? Do you have a common nighthawk where you live? Leave me a comment down below. As always, thank you so much for watching and keep on birding!