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The nightjar is one of our more unusual species of birds. As its name implies, it's nocturnal, so you'll never see one swooping down to your bird table for a morning snack. On the contrary, you'll be most likely to spot it as dusk falls. A member of the Caprimulgidae family; unfortunately, the nightjar is on the amber "at risk" list in the UK - there are an estimated 4,600 mature males. Also known as the Caprimulgus europaeus, the species has gradually made a comeback from the most serious red status, where it was placed between 2009 and 2014 due to declining numbers. Conservation efforts have seen its population rise in recent years, supported by the Wildlife and Countryside Act 1981. A national survey across the UK in 1981 estimated there were between 1,784 and 2,100 mature male nightjars. Numbers increased steadily throughout the 1990s. By 2004, around 4,600 males were identified - a population growth of 36%. Following a further dip in 2009, the population has now been rising steadily for the past seven years.   What does the nightjar look like? Weighing an average of 83 g and at around 27 cm long, with a wingspan of 60 cm, the nightjar has a characteristically wide mouth, helping it to catch its main food source, moths, in flight. They will also eat flies and beetles. Exceptionally good fliers, thanks to their long tail and extra-long, tapered wings; on the ground, it is far less agile, as its short legs make it clumsy with an awkward gait. Its shape is made for flying, like a cuckoo or kestrel. With a distinct flat head, the nightjar's plumage is the colour of bark. The male has white patches on its wings and on the tip of its tail. Its eyes are small and almost reptilian-like. During the mating season in spring, the male has an unusual way of attracting a mate. It claps its wings when a female is in the vicinity. Above, rivals will perform displays of flight that can make them look frantic as they try to distract the female. When hunting, the nightjar's distinctive silhouette can be spotted at dusk. Its long tail and pointed wings make it resemble a small kestrel. It has an unusual call that is almost impossible to describe. It's like a cross between an inconsistent, eerie bird wail, with an almost electronic tinge, crossed with the sonar of dolphins.   What is the nightjar's habitat? Nightjars can be found in the UK on moorlands, heaths, in woodland where there are clearings and on land where there are recently felled conifer plantations. The European species, including the UK's nightjar population, are long-distance migrants, spending the winter in the warmer climate of Africa and migrating in September. They won’t return to British shores until April. Laying their eggs between late May and July, nightjars usually have two broods per year. They normally lay only two eggs - a relatively small number. They typically live to four years old and begin breeding at around one year old. Nightjars are most prevalent in the south of England. Large numbers can be found in Dorset, the New Forest, Surrey's heathlands and Thetford Forest in Suffolk. There are also reasonably-sized populations in parts of Wales, the north of England and southwest Scotland. Several RSPB reserves are also home to nightjars in Devon, Arne in Dorset, North Warren in Suffolk, Aylesbeare and Minsmere. One of the species' favourite spots is said to be Blean Woods in Kent (a 509-hectare woodland that lies northwest of Canterbury), where they have been spotted in large numbers from mid-May onwards. The mixed broadleaf trees, wood anemones, wood sorrel and bluebells provide an ideal environment. For your best chance of seeing a nightjar, take a stroll at dusk, particularly if you live near a heath or lightly wooded area. This is when they are at their most active and it may be your only clue that this fascinating little bird is in your area.