A study of Lapwing breeding population changes in the New Forest, Hampshire

Abstract

A study of breeding lapwings [V. vanellus] on a disused airfield and heathland plot in the New Forest, Hampshire, [UK], over a 9 yr period (1971-1979) revealed a decline from 1975 to 1978 which was contrary to the national trend. Although a wide range of hatching success (90 to 67%) was found in the first 5 yr of study, the average total of young hatched per pair (including repeat clutches where first ones had failed) was fairly constant from year to year within the range 3.6-3.8. During 1976-1978 hatching success averaged only 54.4% (range 62% to 49%) and the average number of young hatched per pair ranged from 1.8-2.4. In 1979 hatching success (73%) was almost at the study period mean, while the average number of young hatched per pair was also almost back to the mean at 3.44. During the first 5 yr of the study, free flight was attained some 37-38 days after hatching, but significantly longer fledging periods (up to 50 days) were observed in the 1976-1978 seasons. In 1979, from a limited first brood sample only, the fledging period was 32-33 days. Mortality percentages during the fledging period were calculated which indicated that up to 1974, 77% of all young failed to survive beyond 30 days from hatching, but thereafter the mortality percentage increased to 100% by 1978. By contrast, again with a limited first brood sample only, mortality was calculated at 68.1% in 1979. Weather conditions of below average rainfall and above average sunshine prevailed during 1975-1977. Such conditions led to a progressive drying-out of the heath and to increased human disturbance of the area, both of which are considered to be major factors contributing to the almost total abandonment of the study area by breeding lapwing. Following abnormally wet conditions over the 1978 to 1979 winter and spring, 1979 saw an increase in the number of breeding pairs, greater hatching success, and low mortality among first brood chicks. It is hypothesized that lapwings capitalize on temporary breeding habitats, such as the study area, when weather conditions render them suitable for successful breeding; this might be a contributory factor to the current national increase of the species.