NUMBERS OF MEADOW PIPITS ANTHUS PRATENSIS ON MOUNTAIN FARM GRASSLAND IN NORTH WALES IN THE BREEDING SEASON

Abstract

SUMMARYOn c. 15 ha of mountain farm grassland in Wales, during 1972‐75, adult Meadow Pipits were present during March–September (but scarce in August–September). Breeding occurred during late April to late July. Incubation was performed by the female but both sexes fed the nestlings. Adults showed an average annual mortality of 54%.Adults spent nearly all their time on the ground, but varied in their activities and use of the habitat according to the stage of breeding. Their unobtrusive behaviour had a marked effect on the ease with which they could be observed for a population count. Males were seen on 30% of the days for which they were assumed to be present and were recorded giving song‐displays on 28% of the days when they were actually seen. We conclude that, to count all the birds present on a site, most must be marked, sightings must be carefully mapped and the number of observer days must be at least 20, preferably in April‐May.The numbers of individually marked (and a few unmarked) birds were determined by mapping them on large‐scale aerial photographs. This gave an average annual density of 48 resident pairs per km2. The average home range was 2.18 ha; this value remained relatively constant from year to year. At low population density individual home ranges were separated from one another, and there was some unoccupied ground, but at high population density the ranges overlapped with one another.