Difference between sexes

When watching a pair of Bonelli´s Eagles, it’s easy to observe a difference in size and colouration: females are bigger and darker than males. This contrast is thought to be an adaptation to the fulfilment of different tasks.

The male

 - During the breeding season, the male is responsible for the feeding of the family. It is lighter and that provides it with more agility in flight and effectiveness in hunting.

- The breeding area may attract other competing individuals or species. The mission of the male is to defend the territory against potential menaces. Its visible white colouration is a clear sign that the territory is already occupied; this is a way of preventing other species from entering there and a way of avoiding fighting. 
       

The female

- The bigger size of the females allows them to cover the eggs completely and keep them at a constant temperature.

- The strength of the females allows them to protect the egg-laying and the chicks from the menace of other predators.