Which statement about territorial defense and fitness is correct?

Which statement about territorial defense and fitness is correct?

• A. Territorial defense reduces fitness.
• B. Territorial defense reduces overlap and competition, increasing fitness.
• C. Territorial defense has no impact on fitness.
• D. Territorial defense increases energy expenditure without benefits.

Answer: (B)

Territorial defense changes the balance of costs and benefits for an individual. By defending a territory, an animal reduces overlap with neighbors and the competition that comes with shared resources. That means more reliable access to food, shelter, and nesting sites, and fewer disruptive encounters with rivals. With resources being steadier and safer, the defender can maintain better body condition and allocate more energy toward growth and reproduction, ultimately increasing its lifetime reproductive success. While defending incurs energy costs and risks, the net effect is often a rise in fitness because the advantages of exclusive access and reduced interference outweigh the costs. The other statements ignore these benefits or overstate the costs, and thus don’t fit as well.

Territorial defense changes the balance of costs and benefits for an individual. By defending a territory, an animal reduces overlap with neighbors and the competition that comes with shared resources. That means more reliable access to food, shelter, and nesting sites, and fewer disruptive encounters with rivals. With resources being steadier and safer, the defender can maintain better body condition and allocate more energy toward growth and reproduction, ultimately increasing its lifetime reproductive success. While defending incurs energy costs and risks, the net effect is often a rise in fitness because the advantages of exclusive access and reduced interference outweigh the costs. The other statements ignore these benefits or overstate the costs, and thus don’t fit as well.