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

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

Karine Aigner / Pauraque (Nyctidromus albicollis) with chick on nest. Texas, USA. June.

Karine Aigner / Pauraque (Nyctidromus albicollis) two chicks in nest. Texas, USA. June.

Karine Aigner / Pauraque (Nyctidromus albicollis) two chicks in nest. Texas, USA. June.

Markus Varesvuo / Egyptian nightjar (Caprimulgus aegyptius), two resting on sand, camouflaged amongst pebbles. Morocco. March.

Ernie Janes / Dusky nightjar (Antrostomus saturatus) Costa Rica.

Ernie Janes / Dusky nightjar (Antrostomus saturatus) Costa Rica.

Staffan Widstrand / Large-tailed nightjar (Caprimulgus macrurus) in Keoladeo Ghana National Park, Bharatpur, Rajasthan, India

Alain Dragesco-Joffe / Egyptian nightjar (Caprimulgus aegyptius) at rest, camouflaged with the soil, Tenere, Sahara, Niger.