Nightjar national breeding surveys in Britain

The Nightjar <i>Caprimulgus europaeus</i> is a red-listed species that is protected under Annex 1 of the EC Birds Directive. Numbers and range have declined in Britain over the greater part of the 20th century, but have begun increasing again since the start of the 21st. The species breeds mainly in southern England, but there are scattered populations as far north as central Scotland. The 1981 national survey located 1784 calling males and estimated the maximum population to be 2100 calling males. (The dataset though only has 1642 birds, the other 142 not having sufficient location information to be mapped.) This was a lower total number than expected. The distribution also showed a contraction of the species? range in the north and west (compared to the 1968-1972 Breeding Atlas). The main cause of the decline was probably a change in climate leading to reduced breeding success, but habitat destruction and disturbance were likely also involved. Information obtained on habitats showed that conifer plantations had become the major habitat type; followed by lowland heath, open bracken areas, other woodlands and raised bogs or mosses. For more information, see Gribble (1983), <i>Bird Study</i> 30: 165-176. The 1992 survey (organised by BTO and RSPB) located 3093 males and indicated that numbers had increased to an estimated 3400. (The dataset though only has 3082 birds, the other 11 not having sufficient location information to be mapped.) This represented an increase of more than 50% since 1981. For more information, see Morris et al. (1994), <i>Bird Study</i> 41: 181-191. The 2004 survey (organised by BTO, RSPB, Natural England, Forestry Commission England, Wales and Scotland) located 4131 males and estimated that the total had risen again to 4606 males (+36% since 1992). (The dataset contains a total of 4197 territory records, comprising 3083 territorial males (10 without location information), six single females, 18 unsexed adults and 46 presumed migrant males ? only noted in May.) National Biodiversity Action Plan objectives for Nightjar conservation were reached in respect of population size and stability, but the target for a 5% range increase by 2003 was not met. (NOTE: In 2005, a further 192 territorial males and 3 unsexed individuals were located in locations (New Forest, Dorset Heaths and East Anglia) not covered during the 2004 survey. However, up to 7 territories may be represented in both the 2004 and 2005 datasets.)