Dieta e comportamento alimentar de Cyanocorax cyanopogon (Wied, 1821) (Aves, Passeriformes, Corvidae) em um ambiente antropizado na região centro-oeste do Brasil

Abstract

The White-naped Jay Cyanocorax cyanopogon (Wied, 1821) is an omnivorous and opportunistic species, with a multifarious diet. In view of the scarcity of available data in the literature, the aim was to investigate and describe the bird’s diet, location of food items, foraging tactics, actual feeding behavior and intraspecific interactions, as a means of defining the items consumed. The study was carried out in a Cerrado area in the Araguaia Campus of the Federal University of Mato Grosso - UFMT, in Pontal do Araguaia, Mato Grosso State, Brazil, from August to December, 2006, and from April to October, 2010. All the feeding events were recorded through 136 hours of animal focal sampling, whereby it was shown that these birds predominantly consume animal nutrients, replenished by vegetable items and human food-waste. Arthropods were predominant in the diet, with ants as the most abundant and frequent item. The fruits, flowers and seeds of eleven plant species were also consumed. Food-waste, representing about 1/10 of the total, was constantly consumed even when other food sources were available. Although active among the various strata, foraging is mainly on the ground. In the event of food-scarcity, the strategy employed is the hierarchical deployment of the members of various-sized groups, with the avoidance of direct competition. This versatility during all seasons, confirms total adaptation to the anthropic environment surrounded by native habitats that characterized the study site.