Long-term changes in the quantity and quality of supplementary feeding of wildlife: are influenced by game managers?

The natural world is now receiving more and more food of anthropogenic origin, which is widely used by a large number of animal species. Among intentional supplementary feeding, one of the most common activities is the winter feeding of game animals, affecting the size, structure and behaviour of their populations. There is a lack of information, however, on long-term trends in supplementary feeding and changes in the type of feeders and feed provided, which can be crucial to understanding game animal dynamics. Our study is based on data collected in the years 1970-2015 in experimental hunting grounds in western Poland. Wildlife feed was provided in traditional feeders and along the ground (ground strips), the latter designed primarily to protect crops from damage by game animals. The first type of feeding activity decreased significantly, while the second increased significantly during the study period. The most frequent types of feed provided were root crops, cereals, hay and silage. Feed amounts between years had a strong auto-regressive temporal character, with a significant lag effect up to ten years. The total dry mass provided for game animals was also characterized by a significant lag effect, although it was weaker in comparison to individual feed types. The auto-correlation is probably a consequence of the availability and ability to store various types of feed over subsequent winters. We believe that the results presented here are the first to describe the problem of feeding animals over decadal timescales and indicate the modifications to feeding that have taken place, influenced by the animals, crop prices and social factors.