Quantitative and Qualitative Composition of Diet of the Ural Owl, Strix Uralensi (Strigidae, Strigiformes), in the Central Part of European Russia (The Example of the Republic of Mordovia)

Abstract

Abstract The results of the study of the Ural Owl feeding spectrum are presented. In Russia the Ural owl eats over twenty species of mammals, thirty bird species and a number of animals of other classes. The research tasks included the identification of the species of the victims of a large owl in Mordovia, their quantitative data and the characteristics of osteological material from pellets. It was found out that mammals, in particular rodents, are the basis for the Ural owl food. The Ural Owl’s diet consists mainly of gray voles (47.7 %). On the second place there is a red vole (31.4 %). The share of mice is only 7.3 %. Th e predator hunts for the forest mouse most oft en. In pellets the mass fraction of bone remains varies in the range from 3.4 to 44.8 %. Th e average proportion of bone remains is, as a rule, up to 25 %, with the content of only one or two small rodents in pellets; the remains of three to six individuals - up to 45 % of the weight of dry pellet. Among all the bones of mammals, the lower jaws, femoral and tibia bones give the greatest information about the number and composition of victims of the Ural owl. In pellets the brachial and nameless bones of the victims are presented in smaller numbers.