Does provision of supplementary food to grey partridges Perdix perdix help their over-winter survival on upland hill farms in Northern England?
Abstract
Grey partridge populations in the UK have declined dramatically since 1970. These birds are mainly associated with lowland cereal farms, but they are also found on marginal hill farms in northern England where they frequent rough grasslands created by low-intensity sheep farming. Here, important populations remain, but the availability of winter food, particularly in years with prolonged snow appears a major limiting factor. To investigate whether food shortages in winter limit grey partridge survival, we experimentally tested whether we could improve their survival by increasing the provision of supplementary food within five study plots, each paired with a control, over two consecutive winters. Grey partridges found and used feeding stations, with discovery time on average 12 days earlier in the second winter. The frequency of hopper use also increased on four of the five fed plots in the second winter. We found no differences in an index of over-winter survival nor subsequent breeding success in relation to the feeding treatment. However, the study coincided with two mild winters with little snow and the provision of supplementary food may be more important in more severe winters with prolonged snow cover. Grey partridges readily used feed hoppers and we recommend their provision to provide emergency food sources in severe winter weather whilst longer-term land-use based solutions are sought.