Golden eagles live in the wild, rocky north of Portugal, where the mountains are quiet and high. They build huge nests on cliff edges where nothing can climb up to them. The same pair of eagles may use the same nest for 50 years.
An eagle's eyesight is incredible. It can see a small animal from over 2 km away - that's like spotting a rabbit on the other side of your nearest town. When it spots prey, it folds its wings in and dives. A diving golden eagle can reach 300 km/h - the same speed as a Formula 1 car.
Golden eagles are very loyal. A pair usually stays together for their whole life, sharing the work of building the nest, sitting on the eggs, and feeding the chicks. The chicks stay in the nest for around 70 days before they finally fly out for the first time.
Portugal protects its golden eagles carefully because there are not many of them. People who study them often watch the nests from far away with special telescopes, so as not to disturb them. A good eagle-watcher can sit very still for hours and never make a sound.