Comparative analysis of the behavior of the Common crane (Grus grus) and Demoiselle crane (Anthropoides virgo) (Gruidae, Aves) during their pre-migration period

Abstract

Studying of animal behavior is important to understand the evolution and ecology of species, as well as to develop strategies and measures to conserve rare species. Investigating the time budget of closely related species allows detecting species-specific patterns of behavior. A comparative analysis of the time budget of the Common crane (Grus grus) and Demoiselle crane (Anthropoides virgo) in their pre-migration period, during which they as a rule feed in agricultural fields, was carried out. Species differences in the foraging strategies were revealed. Demoiselle cranes forage while moving across the field while Common cranes forage while standing still. Thus, Common cranes, which traditionally use fields to feed, forage less energy-intensely than Demoiselle cranes that are a steppe species and began to use agricultural landscapes after virgin lands since the middle of the last century. Common cranes spent more time preening than Demoiselle cranes, and juveniles of both species spend less time to this activity than adults but no statistically significant differences were found. Both species spent the least time to rest and other activities.