Backyard feeders appear to be having an impact on hummingbirds, with some outlets suggesting they may be helping or hurting wildlife. A study has found that hummingbirds, specifically in California, have undergone a change in the shape of their beaks, potentially in response to the use of backyard feeders. The exact implications of this change are not clear, but research suggests that the beaks of California hummingbirds have evolved to adapt to the feeders.