White form gyrfalcons are the only predominantly white falcons. During summer, peregrine falcons, gyrfalcons, and golden eagles build nests on cliffs. Predatory birds include rough-legged hawks, gyrfalcons and golden eagles. The wood's fauna include stags, boars, storks, grey herons, gyrfalcons, white-tailed eagles, and kites. Currently housed in Nottingham Castle Museum and Art Gallery, it depicts two snowy white gyrfalcons. The Great Khans favored gyrfalcons, furs, women and Kyrgyz horses for tribute. Silver gyrfalcons resemble a light grey lanner falcon of larger size. Gyrfalcons that survive into adulthood can live up to 20 years of age. Thus, both wild and captive gyrfalcons can be protected from bird flu by vaccination. Gyrfalcons are rare winter vagrants to the Altai falcon's range.