Productivity of saker falcons (Falco cherrug) in Mongolia

During the summers 1994-1995, over 80 eyries were located on over 10,000 km of survey routes in Mongolia. Where possible, production and hatch dates were assessed when the eyries were found. For 75 nesting attempts, breeding success was found to be 92%. The average number of young per brood was 28 for 68 attempts. The number of young fledged per pair by year were 3.2 in 1994 and 2.6 in 1995. Productivity values for western Mongolia were 3.1, central 3.4, and eastern 2.5. Similar values for three habitat types were 2.8 in mountain, 3.1 in foothill, and 2.4 in flat habitat. Support type comparisons were: 2.9 young for cliff nests, 3.5 young for trees, 1.9 young for utility poles, and 2.5 young for other artificial structures. These values (except for the utility pole sites) represent a highly productive population.