larger but browner gyrfalcon. It is larger and more heavily built than the related lanner falcon. Saker falcons tend to have variable plumage. Males and females are similar, except in size, as are young birds, although these tend to be darker and more heavily streaked. The call is a sharp kiy-ee or a repeated kyak-kyak-kyak. Ecology The saker falcon is a raptor of open grasslands preferably with some trees or cliffs. It often hunts by horizontal pursuit, rather than the peregrine's stoop from a height, and feeds mainly on rodents and birds. In Europe, ground squirrels and feral pigeons are the most common prey items. This species usually builds no nest of own, but lays its 3–6 eggs in an old stick nest in a tree which was previously used by other birds such as storks, ravens or buzzards. It also often nests on cliffs. Saker nests support a species-rich assemblage of commensal insects. Status and conservation BirdLife International categorises this bird as endangered, due to a rapid population decline, particularly on the central Asian breeding grounds. Ever since the collapse of the Soviet Union, the United Arab Emirates have been the main destination for thousands of falcons caught and sold illegally for hefty sums at the black market. Kazakhstan is estimated to lose up to 1,000 saker falcons per year. The species also faces pressure from habitat loss and destruction. The population was estimated to be between 7,200 and 8,800 mature individuals in 2004. However, sakers live at low densities across large ranges in remote regions, making distribution status difficult to assess. A climatic niche modelling study pinpointed certain remote areas for targeted population surveys. In the United States, Canada and Europe there are several captive breeding projects. The most dramatic decline of the saker falcon in Asia has been in Kazakhstan and Uzbekistan. In contrast, a strongly protected and relatively abundant population persists in Hungary. Saker falcons are known to be very susceptible to avian influenza, individuals having been found infected with highly pathogenic H5N1 (in Saudi Arabia) and H7N7 (in Italy) strains. Therefore, an experiment was done with hybrid gyr-saker falcons, which found that five falcons vaccinated with a commercial H5N2 influenza vaccine survived infection with a highly pathogenic H5N1 strain, whereas five unvaccinated falcons died. This means that sakers could be protected from bird flu by vaccination, at least in captivity. In culture A Hungarian mythological