THE RETURN OF THE MERLIN TO THE SOUTH PENNINES

This paper reports on the findings of a large number of people engaged in the study of the Merlin Falco columbarius population in the south Pennines. Between 1980 and 1992 the number of nesting areas found to b e occupied by Merlin increased from two to 66, and the proportion of c hecked sites found to be occupied rose from 29 to 78%. The apparent in crease in the size of the population was not solely a result of increa sed observer activity. The fao occupied nests found in 1980 and 1981 w ere in trees in grassland areas, but thereafter nearly all were on the ground amongst heather. Compared to the study area as a whole, grass moor was less frequent and heather moor more frequent within a 1.5 km radius of the nesting area. Nearest-neighbour distance varied from 5.7 km in 1985 to 2.1 km in 1992, remaining relatively stable in comparis on to the increasing size of the population. Nesting areas were aggreg ated in comparison to a distribution of random points. The density of nesting areas was greatest between 0.25 and 1.5 km from the moorland e dge. This paper demonstrates that collaboration between conservation p rofessionals and dedicated volunteers can succeed in monitoring popula tion change.