Nightjars are medium-sized nocturnal or crepuscular birds in the subfamily Caprimulginae and in the family Caprimulgidae, characterised by long wings, short legs and very short bills. Some New World species are called nighthawks. The English word "nightjar" originally referred to the European nightjar. Nightjars are found around the world except in New Zealand and some islands of Oceania. They usually nest on the ground, with a habit of resting and roosting on roads. The subfamilies of nightjars have similar characteristics, including small feet, of little use for walking, and long pointed wings. However, typical nightjars have rictal bristles, longer bills, and softer plumage. The colour of their plumage and their unusual perching habits help conceal them during the day.