The blackbirds are an important part of the plot of this novel for several reasons. First, they are the spectacle that brings the birdwatchers into Wicklow, revitalizing the town in a few short weeks with the business these people conduct during their time in town. Second, the blackbirds are tree keepers that watch over the tunnel between two mulberry trees that the legend says connect the mortal world to the world of the dead. Finally, the blackbirds, according to Zee’s retelling of Celtic legend, are the spirits of deceased women of the Callow family who watch over the mulberry trees and the people of Wicklow.

The blackbirds symbolize hope because their songs provide a connection between the living and their dead loved ones. When their songs are silenced after Zee’s death, the plant life in Zee’s garden suffers, but when the songs return, the trees and vegetables thrive. In this way, they become a motif of the theme of Grief and Guilt and a symbol of the magic present in this novel. As the spirits of the deceased women of the Callow family, they symbolize the love that continues to exist between Anna Kate and her mother and grandmother.