ll y a pas mal de fautes, donc voici le texte corrigé:
My favourite animal is the eagle. It (animal non familier) lives on the mountains' rocks, in America. It (majuscules!) eats dead animals or (enlève le pronom personnel ici, car ça devient lourd^^) hunts small animals, mice (a mouse=two mice), small birds,rabbits,etc.....
It weighs 20kg and (pareil, enlève le pronom) sizes 2 meters with the wings spread.
Its habits are (pluriel!) hunting (-ING), sleeping and eating. It loves (pas de to, mais -ING!) flying. Its abilities are that it can fly at 230 km/h and it can kill very small animals, but it can't run and swim. Its expectency is 70 or 75 years.