How does the author use imagery in the novel, The Witch Elm?

The imagery of birds is used to symbolize the predatory nature of the detectives. Toby frequently compares Rafferty to birds of prey, such as the owl which attacks Toby and Leon at the end of Chapter 9. He also compares Detective Martin’s stare to that of a seagull. Birds are not only predatory but ominous, such as the blackbird which Toby temporarily chases away with his cigarette smoke. Birds are also able to fly in and out of the garden at will, symbolizing the ability of the police officers to ignore the boundaries of Ivy House and enter Toby’s refuge at will.