.The ravens of Erebor had a special relationship with Durin's Folk and could speak and understand the common tongue. The Dwarves could understand some bird-speech (crows, for example) but not that of the thrush. Bard and his ancestors had a special gift that allowed them to understand the speech of birds such as the thrush....what was the bird species at the Lonely Mountain?...and could it communicate with Bard and the Dwarfs?!... vielen danke.