On the diet of the Magellanic Great Horned Owl (Bubo virginianus magellanicus) in andean central Chile

Abstract

The Magellanic Great Horned Owl,or tucúquere (Bubo virginianus magellanicus), is a bird of prey of agroecological and environ- mental importance in Chile. However, there is a gap in what we know about its diet in mountainous regions of central Chile, where its inter- action with the human populations is large and anthropic-derived habitat changes are increasing. We collected 91 pellets from two individu- als to assess their diet. Analysis of pellet weight, length and width, prey identification to species, as well as absolute an d relative abundance, were obtained. From these values, we calculated trophic niche (Levin, Shannon-Wiener, and Smith indexes). The mean weight, length, and width of pellets were 9.84 g, 56.7 mm, and 32.6 mm, respectively. The consumption of 12 different prey species was evidenced, being the most consumed the introduced hare Lepus capensis (23.53%), followed by the chinchilla rat Abrocoma bennetti (20.59%), and thereafter other species of small rodents, an undetermined bird, and insects. The trophic niche amplitude for normal and standardised Levin, normal and standardised Shannon-Wiener, and Smith (TF) indexes were 6.72, 0.52, 2.11, 0.85, and 0.90, respectively. This is the first evidence of a diet based predominantly on L. capensis in central Chile for B. v. magellanicus, which seems to be a more generalist predator than previous studies report. Out study contributes to the understanding of food habits and conservation efforts for this raptor species in Chile and the rest of South America.