A spectacular sight: Migration of Nighthawks
As the sun began to set over Camas National Wildlife Refuge last week, the flight patterns over the marsh became very busy as evening feeding birds took flight. The Short-eared owls were joined by the non-competing insect eating, migrating Common nighthawks who are headed for South America for the winter.
During my visits to the refuge during the summer, I would visit a roosting male nighthawk among the dead willows on the bank of Camas Creek. Rarely was he not there but last week many dead branch on the cottonwoods also had nighthawks.
Nighthawks are misnamed as they are neither a hawk nor they feed at night, but are insect eaters and feed by sight at dusk and dawn when insects are most active. They do not have night vision but their eyes are structured to reflect light back to the retina to improve their sight in low light. They are often attracted to clouds of insects around bright lights and consume thousands of flying insects daily feeding on moths, mosquitos and even grasshoppers.
One of the most interesting habits of the Common nighthawk is for the male to fly just above the trees and make a steep dive toward the ground. As he peels out of the dive he flexes his wings down causing a booming sound as the air rushes over his wing tips. These displays are mostly used to attract a female but is often used in agnostic attacks on intruders. These displays and its flight patterns have given the nighthawk a nickname of “bullbat.”
Nighthawks are mostly solitary and very territorial, but during migration they form large flocks as they head for South America to enjoy the winter. At times males appear as party animals as they will roost together, leaving the females to fend for themselves.
These insect eaters are not nest builders as they, like killdeers, nest on the bare ground laying only one or two speckled eggs. They usually nest in the high desert area or cleared forest. On a recent rock hunting trip near Challis, I flushed a nighthawk who appeared wounded until it led me away from the nest area and flew away. Both the eggs and the young are camouflaged on the rocky bare ground.
These birds are declining rapidly. It is estimated that since 1966 to 2014 they have declined almost two per cent each year in the United States. A few years ago one of the most popular places for them to nest was on gravel roofs but those have been replaced by better roofing methods making them totally ground nesters. Mosquito abatement and other flying insect programs have lessened the amount of insects available for them to feed on.
This week I went back to Camas NWR to look for more nighthawks, but found none and thought they had moved south – they had. A day later I found a large flock of more than 40 working the marshes at Market Lake near Roberts. Their wings with a white band was the identifying feature as they swooped and sliced through the air picking up dinner.
Fall migrations are at full swing with songbirds, shorebirds and even hawks gathering to head south. It is a great time to visit area gathering places for these birds for great entertainment.