The RSPB team at Geltsdale have conducted evening Nightjar surveys recently, so we are sharing some facts about these nocturnal birds, which can be seen hunting for food at dusk and dawn. Nightjars (Latin name: Caprimulgus europaeus) have mottled, barred, grey-brown feathers which resemble bark, helping to camouflage them during the daytime. They also have pointed wings, long tails, flat head, large, dark eyes and short, thin, black beaks. They are similar in shape to Kestrels, and measure between 26 and 28 cm in length, weigh 65 to 100g, and have a wingspan of 57 to 64 cm. Males have patches of bright white on the tips of their wings and tails, which can be seen when they are displaying to attract females.
Male Nightjars make a churring song which rises and falls, which is usually the first sign one is near, but they are silent in flight and can be very hard to spot. They are found in woodland and heathland and eat insects, particularly moths, flies and beetles, catching them at night on the wing in their wide mouths. They are summer visitors to the UK, arriving from Africa in the spring, from April to May, and spending the summer months here to breed, before returning to Africa in September.
Nightjars breed between late May and August, laying their eggs directly on the ground instead of in a nest. The eggs are bark coloured, like the birds themselves, which helps camouflage them on the ground. They usually lay two eggs and have two broods of chicks while in the UK. The chicks hatch after around 20 days and fledge about two weeks later.
The ‘Caprimulgus’ part of the Latin name for Nightjars means ‘goatsucker’, which refers to the mythical belief that Nightjars drink goats’ milk. This came about as they were often found near livestock, however they were actually feeling on swarms of insects, not stealing the milk from goats! The species is listed as Amber under UK Birds of Conservation Concern, and it is thought that loss of habitat is the biggest issue for Nightjar populations. If you are taking an early morning or dusk walk in or around RSPB Geltsdale, listen out for the Nightjar’s distinctive call, and you may even be lucky enough to spot one and see the males displaying and ‘wing clapping’ to attract a mate.