Supplementary winter food for gamebirds through feeders: which species actually benefit?
Providing supplementary winter food for gamebirds through feeders is an important management tool for many game managers, but there has been no systematic study of how much of the food is consumed by gamebirds, by undesirable pest species, and by songbirds of conservation interest. Nor is anything known about the effects of feeder location on the attractiveness for game and other wildlife. We used camera traps to assess the above at 259 game feeders containing wheat grain at 3 lowland farms in southern England during the winters of 2012 and 2013. We conducted both paired feeding trials, where we set 1 feeder along hedgerow cover and the other 40 m into the adjacent field, and unpaired feeding trials, where we set only 1 feeder. We changed the location of existing feeders along hedgerow cover every 7–10 days to assess the time needed by wildlife to find new feeder locations and tested whether displaying rook (Corvus frugilegus) carcasses on top of the feeders reduced the number of corvids visiting feeders. No pest control was conducted at the feeders. We recorded 47 species in total (33 birds and 14 mammals). Feeders were visited by gamebirds and songbirds in early and late winter, but rodents, columbids, corvids, lagomorphs, predators (mammals and raptors), waterbirds, and other species accounted for 54% of visits and consumed 67% of grain provided. We recorded higher numbers of gamebirds, songbirds, rodents, and columbids per photograph at feeders along hedgerow cover than in the open, whereas corvids were more numerous in open fields. All brown rats (Rattus norvegicus, 17% of visits across seasons and sites) were photographed at feeders along hedgerow cover. After the change of location, gamebirds and songbirds located feeders at new locations within 1–3 days, whereas rodents needed 2–4 days. Rook carcasses reduced the number of corvids photographed at feeders by 55%, and number of songbirds by 83% but did not affect gamebird attendance. To prevent gamebird feeding practices from being inefficient and potentially counterproductive for ecological and economic reasons, feeders should be set along hedgerow cover when rats are properly controlled and in open fields when no control of rats is conducted, and their locations changed regularly.