eagle eye
n.— «Outside the summer months, pigeons form 85 per cent of a peregrine falcon’s diet, and sparrowhawks take a lot. There was research at Lancaster University on the use of deterrents. Eagle eyes—roundel transfers on the bird’s body—were tried, to scare raptors, but that worked only for a short time because the hawks got used to them, as they did with other deterrents such as bells and shiny sequins.» —“A Life in Sport: Chris Gordon” by Charles Randall Telegraph (United Kingdom) Oct. 11, 2006. (source: Double-Tongued Dictionary)