Why do larger birds require more territory for nesting?

Larger birds require more territory for nesting primarily because they need more food and shelter. Larger species tend to have higher energy needs, which dictates that they need access to greater quantities of food resources. This reflects their size and metabolic rates, as they require a sufficient food supply to sustain their body weight and energy levels. Additionally, larger birds often need more habitat space to find adequate shelter and suitable nesting sites, as well as to support their young once hatched. This combination of higher food requirements and greater shelter needs leads to a necessity for a larger territorial range compared to smaller birds, which can thrive in more compact areas.

The other options relate to different aspects of bird behavior and physiology. While space for flight is important, it’s not the primary reason territory size increases with bird size. Similarly, while larger birds can be more aggressive and territorial, this aggression does not inherently mandate a larger territory; rather, it often relates to the food supply within a given area. Lastly, although larger birds might not have the same flight speeds as smaller birds, the speed of flight does not directly influence their territory needs. Thus, the energy demands of feeding and shelter are the key reasons why larger birds occupy larger territories for nesting.