Murray Cooper / Swallow-tailed Nightjar (Uropsalis segmentata) female in defensive posture on nest, South America

Alan Murphy / Buff-collared Nightjar (Caprimulgus ridgwayi) calling, Arizona

Glenn Bartley / Eastern Whip-poor-will (Antrostomus vociferus), Ontario, Canada

Matthew Studebaker / Common Nighthawk (Chordeiles minor), Montana

Laurent Geslin / Nightjar {Caprimulgus europaeus} with chick on ground, UK.

David Tipling / Nightjar {Caprimulgus europaeus} male in display flight at dusk, North Norfolk, UK, June

David Tipling / Nightjar {Caprimulgus europeaea} male in display flight at night, North Norfolk, UK, June

David Tipling / Nightjar {Caprimulgus europaeus} male churring on song post at dusk, North Norfolk, UK, June

David Tipling / Nightjar {Caprimulgus europaeus} at nest in threat display towards advancing Adder, North Norfolk, UK, May

Mike Wilkes / Nightjar (Caprimulgus europaeus) on nest. England, UK, Europe

David Kjaer / Nightjar on nest, England

Dong Lei / Grey nightjar (Caprimulgus indicus). Simao, Pu'er Prefecture, Yunnan Province, China.