Intraspecific Differentiation of the Oriental Cuckoo (Cuculus optatus) within the Range: Relationship with the Abundance of Host Species

Russian Journal of Ecology - The distribution of C. optatus host-specific races within the breeding range has been analyzed. It has been found that these races are geographically separated: their...     

The Diet of the Great Gray Owl,Strix nebulosa,at Different Levels of Prey Abundance during the Nesting Season

Variation in the diet of the Great Gray Owl, a specialist predator, at different levels of prey abundance in different biotopes was studied in the middle Transural region. Microtus voles were found to be the main prey, with shrews being alternative prey. In different plots, two types of change in the diet were observed during the nesting season: (1) substitution of Microtus voles inhabiting meadow biotopes by Microtus voles characteristic of forest habitats, and (2) substitution of the latter by shrews.