Nighthawk

It's almost the end of May and the spring migration is coming to a close. Winter visitors, like the white-throated sparrow and the golden-crowned kinglet, have left to breed in the great, temporarily not-so-white north and passers-by, like the Nashville warbler, have continued on their way after a rest and a snack. Among those species that stay for the whole season, many have already begun to go about the business of breeding, while a few stragglers continue to arrive - only during this past week have the eastern wood-peewees, serenaders to the dog days of summer, started to show up as invisible whistlers high the canopy. 

A common nighthawk in flight (1)

Yesterday evening, I was sitting out on the stoop of my building, listening to the birds singing from the woods, when I looked up and saw another late arrival swooping high up over my head - a common nighthawk (Chordelies minor). Nighthawks are members of the family Caprimulgidae, a group commonly referred to as nightjars or goatsuckers, due to an old legend that they suck the milk of goats (they don't, but the name is still great and its stuck around). Like most goatsuckers, common nighthawks are medium-sized birds with long, pointed wings, short legs, and small beaks. They are acrobatic, aerial predators of flying insects that hunt mostly as dusk and down, distinguishing them from other members of the family, such as the whip-poor-will, which hunt later at night. 

Nighthawks are especially well known for their impressive mating displays, during which males dive rapidly through the air before suddenly swooping back up again, beating their wings in such a way that the air passing over them makes a loud boom or whooshing sound. Once they have found a suitable mate, female nighthawks lay their eggs on the ground in open, often recently burned areas or in cities on the flat, gravel roof tops of certain buildings, where their well camouflaged young are safe from nest predators like cats and raccoons. 

A female common nighthawk at rest on the ground (2)

Common nighthawks are often one of the last spring migrants to show up in their breeding ranges, but they do have a pretty good excuse for their tardiness. The migration route taken by nighthawks is one of the longest of any North American bird, taking some individuals from Argentina all the way up to Canada. To accomplish this feat, nighthawks start early, typically leaving their breeding grounds in August and flying during all hours of the day until they reach their winter destinations. The species breeds throughout most of the United States and Canada, passes thought most of Mexico during migration, and winters across much of South America; what's more, it can be seen in both rural and urban areas, making it a truly cosmopolitan bird observable by just about anybody in the Western Hemisphere.  

I wasn't sure if the nighthawks that I was seeing yesterday were going to stay for the summer or if they were only passing though, so made sure to savor the opportunity to watch them as much as I could. Unfortunately, common nighthawks have been declining in numbers over the past few decades, likely due to a combination of habitat loss (including a decline in flat, gravel rooftops) and reductions in their insect prey due to widespread pesticide use. As a result, fewer and fewer people are getting the opportunity to watch their graceful flights through the pale dusk sky. 

This is a real shame. Long-range migrants like the nighthawk are the unexpected acquaintances of the animal world, the moon and the north star and the no-way-I-have-a-cousin-in-Chicago that connect strangers across huge distances through shared experience. They are a clear example of how the activities of industrial farms in Iowa and landlords in New York can fundamentally change the night skies of Amazonia and vice versa. When we lose them, we lose a visceral reminder of the invisible strings that connect us across artificial boarders, traced yearly in feathers and wonder. Those connections make us vulnerable, but they also mean that when we act collectively, we can make big things happen by doing what we can in our own backyards. We can keep common nighthawks common by installing gravel nesting areas on flat, urban roof tops, by cutting back on pesticide use, and by creating open habitats through controlled burns. 

As is often the case in conservation, these actions may require us to go a little out of our way and resist the modern insistent on efficiency in everything, but all in all, the nighthawk, common urban bird that it once was, has shown that it is able to put up with fair amount of human disturbance. If we can't move over and make some room for a species like that, what is to become of the rest of our connections?

Sources:

American Bird Conservancy (2023). Common nighthawk. ABC's Bird Library. https://abcbirds.org/bird/common-nighthawk/ 

Peterson, R. T. (2020). Peterson field guide to birds of eastern and central North America (7th edition). Houghton Mifflin Harcourt.

The Cornell Lab of Ornithology (2023). Common nighthawk. All About Birds. https://www.allaboutbirds.org/guide/Common_Nighthawk 

Photo Credits:

(1) Common Nighthawk in flight 08-20180619 - Kenneth Cole Scheider CC BY-NC-ND 2.0

(2) Common nighthawk (female) - Andy Writhmell (Florida Fish and Wildlife) CC BY-NC-ND-2.0