Variation in Aggression of Black-Throated Blue Warblers Wintering in Jamaica

[摘要] Abstract. Variation in aggression among birds on different territories has been hypothesized to be influenced by intrinsic factors such as a bird's age, sex, or size and extrinsic factors such as density of neighbors, abundance of food, or territory size. However, little work has examined how and why aggression may vary within a bird's home range. We examined variation in aggressive behaviors of nonbreeding Black-throated Blue Warblers (Setophaga caerulescens) in Jamaican coffee farms by using experimentally simulated intrusions into home ranges. Our multivariate models confirmed that multiple variables associated with aggression included sex, home range size, proximity of intrusion to home range center, and the presence of another aggressive bird in the area. In addition, we found that birds responded more aggressively to intrusions in shade trees, where insects were more abundant, than in the understory of coffee or of small patches of remnant forest. These results suggest the birds responded to variati...

[学科分类] 动物科学

[关键词] aggression;behavior;coffee;defense;home range;territoriality;warbler.