“Both male and female S. rufus are territorial; however, they defend different types of territories. The more aggressive males fight to defend areas with dense flowers, pushing females into areas with more sparsely populated flowers. Males generally have shorter wings than females, therefore their metabolic cost for hovering is higher. This allows males to beat their wings at high frequencies, giving them the ability to chase and attack other birds to defend their territory. The metabolic cost of short wings is compensated for by the fact that these males do not need to waste energy foraging for food, because their defended territory provides plenty of sustenance. Females on the other hand are not given access to the high concentration food sources, because the males fight them off. Therefore, females generally defend larger territories, where flowers are more sparsely populated, forcing them to fly farther between food sources. The metabolic cost of flying farther is compensated for with longer wings providing more efficient flight for females. The differences in wing length for S. rufus demonstrate a distinct sexual dimorphism, allowing each sex to best exploit resources in an area.”
I copied this straight from Wikipedia. Fascinating. Fair? For some reason, I trust their information for basic science, though I might be skeptical for more subjective knowledge. Around here, we call these birds “little bulldogs,” or more subjective epithets. I love them despite their aggression; they are beautiful, remarkable creatures. I am grateful to have the Rufous and the other two species zipping around the yarden all day, intensifying in the evening.