Introduction

Although arguably the most studied nightjar in North America, the Common Nighthawk remains poorly known. Most studies of this species have been short-term and anecdotal in nature and specific data about much of its life history are scarce, particularly from the southern part of its breeding range and from its South American wintering grounds.

This nighthawk is often observed on the wing, hawking insects at dusk and dawn over urban and rural areas. Its loud, nasal peent calls, spectacular booming courtship dives, and erratic, almost batlike flight (hence the colloquial name “Bullbat”) make this a familiar bird to anyone who spends time outdoors on warm summer evenings. In many ways, the name “nighthawk” is inappropriate for this bird because it is most active at dawn and dusk, not night, and like other members of its family, is not related to the hawks.

This is a species that actively pursues flying insects on the wing, often feeding on those attracted to streetlamps and other bright lights. Although it nests most often on open, cultivated fields, gravel beaches, rocky outcrops, and burned-over woodlands, it is well known for its propensity to nest on flat gravel roofs, especially in cities. Whether nesting on roofs or natural sites, it makes no nest per se but usually lays its eggs directly on the ground; the species cryptic plumage makes nesting birds difficult to see. Both the female and male, which are similar in size and appearance, feed regurgitated insects to their chicks.

Recent data suggest a general decline in numbers of this species, perhaps owing to increased predation, indiscriminate use of pesticides, or habitat loss. Nine subspecies have been recognized based on plumage color and size.