Autumn–winter diet of Grey Partridges Perdix perdix in winter crops, stubble fields and fallows

Abstract

Capsule Diet composition differed significantly between winter cereals, winter oil-seed rape, stubble fields and permanent fallows. Aims To determine the composition of the diet of Grey Partridges in autumn and winter in four agricultural land-cover types, characteristic of lowland areas of Central Europe. Methods Faecal analysis was used to determine diet. Multivariate analysis of variance (manova), Simpson Index of Diversity (sid) and Detrended Correspondence Analysis (dca) were used to assess variation in the proportions of the six main dietary components (cereal and broad-leaved plant leaves, weed seeds cases, cereal grains, husks of grasses and other plant material). Results Thirty-seven different kinds of plant food items were found, and the most numerous were cereal leaves (58.2% in total of all items), followed by leaves of broad-leaved plants (21.8%), weed seed cases (13.3%), cereals grains (3.5%), husks of grasses (1.2%) and other plant material (2.0%). Diet composition differed significantly between winter cereals, winter oil-seed rape, stubble fields and permanent fallows. The dca showed that the two first axes explain 38% of the total variance of the diet. The diet diversity was highest in stubble fields and permanent fallows, and the smallest in winter cereals. Dietary diversity was negatively correlated with the overall abundance of leaves, and positively with the abundance of weed seeds, cereal grains and husks of grasses. Conclusion Cereal leaves might replace other food items, which suggests that food resources are not a critical factor limiting the population of Grey Partridges during winter. A high proportion of weed seeds and cereal grains in the diet of Grey Partridges in stubble fields confirms the importance of these fields as sources of food of high-calorific value. Maintenance of stubble fields and cover crops with natural regeneration of annual weeds should constitute an important element of a strategy for the recovery of Grey Partridge populations in arable landscapes in Europe.