Despite name, bird is neither common nor hawk

  • A female common nighthawk. Courtesy of Rebecca Suomala

Friday, August 18, 2017

As August arrived, many people lamented that the summer is waning. In fact it is, and numerous natural events that we associate with fall, such as bird migration, actually begin in August. Some songbirds, shorebirds and insect eaters like the common nighthawk begin their south-bound journey in the second half of August.

Migration is difficult, but common nighthawks must contend with a variety of additional challenges.

One is their name.

The common nighthawk is not common. It is actually listed as an endangered species in New Hampshire and has been experiencing dramatic population declines across most of its range from Canada to Panama. It is declining most rapidly in the northeast United States.

Breeding bird atlases from this region have noted a 70 percent drop in occupancy rate of historical nesting territories. Surveys taken in the 1980s recorded 24 nighthawks during breeding season in downtown Concord. In 2013 and again this year, there were no confirmed nests in the capital city. There were also no nests in Keene or Franklin this year. The only region of the state where nighthawks seem to be holding their own is the pine barrens of Ossipee.

They also are not hawks, but are actually related to the Eastern whippoorwill. Like the whippoorwill, they are mottled brown and about the size of an American robin, with long, pointed wings. Their wings have a bold white band across them which can be seen when they are flying. Their flight is distinctive and erratic as they flit about pursuing insects.

Whippoorwills and nighthawks are in a family called “goat-suckers,” a name based on a legend that goes back over 2000 years, claiming that these birds with their large mouths would visit she-goats at night and suck their milk. No evidence was ever found to verify this notion, but the large mouths are very effective as insect nets, scooping up mosquitoes, moths, beetles and many other flying insects.

The nesting habitat of these birds is unusual. They don’t create a nest, but lay their eggs on the ground or on flat gravel roof tops. In the past, when there were more fields and pea-stoned roofs, there was more favorable habitat. As fields have grown up to forests or become housing developments and gravel roof tops have been replaced with rubber or plastic, the common nighthawks have lost their ideal nest sites.

Loss of nesting habitat is one possible reason for their decline, but the fact that they eat insects may be another. Use of pesticides, both on their breeding grounds in North America and in their South American wintering territories where pesticide use is less regulated, has reduced their food source.

Climate change and more severe weather events probably have an effect as well. In recent years, cold and rainy springs have correlated with a decline in successful nests.

Biologists don’t have all the answers to explain the decline in the nighthawk population but there are still opportunities to see significant numbers of nighthawks during migration. Birds that breed in Canada and the northern U.S. funnel into migration routes and can be seen in large numbers as they fly through our area.

Volunteers with the New Hampshire Audubon stage a migration watch in downtown Concord each August to tally the birds that pass overhead. In recent years, the peak days have fallen about Aug. 23 and 30.

On such days, or rather evenings, more than 2,000 nighthawks have been counted streaming over the city within a two- to three-hour period. Migration is weather dependent and it seems that warm southerly breezes provide the best time to watch for an influx of nighthawks in this area. Another factor is the emergence of flying ants. When there are high numbers of these insects, more nighthawks are observed. The nighthawks feed on the fly during migration. It is a spectacle worth checking out.

If you are interested in observing nighthawks during migration, visit the N.H. Audubon website, nhaudubon.org, or Facebook page, facebook.com/nh.audubon, for updates on the times and locations of the downtown Concord watch. Experienced volunteers will help identify and interpret the observations.

Additional information about nighthawks can be found at nhbirdrecords.org/bird-conservation/project-nighthawk and N.H. Fish and Game’s Wildlife Action Plan at wildlife.state.nh.us/wildlife/documents/wap/appendixa-birds.pdf.