Territoriality in the Orange Billed Sparrow: Convergence Of Male And Female Roles

Defending and maintaining territories is very important to most bird species. There is more information about temperate region birds than tropical region birds because most studies have been done in temperate regions. Recent studies have shown that the roles of the sexes may often converge in the tropics. To examine this idea, I studied the territorial behavior of the neotropical Orange-billed sparrow (Arremon aurantiirostris). This species maintains territories year round and both sexes sing and actively participate in territory defense. We wanted to test if the female were more aggressive than the males in territorial behavior to stimulated intrusions. At different territories we used playbacks as a stimulated intrusion. We had three different types of stimuli: male song only, female song only and, combination male-female (duet). Our results showed that males were more generally aggressive than the females. Males showed more aggression to all three stimuli, they approached closer and quicker. Females did show territorial behavior as well but were not as aggressive.