Date of this Version
Erforschung biologischer Ressourcen der Mongolei (2010) 11: 177-188.
We studied the nesting ecology and movement patterns of Eurasian black vultures (Aegypius monachus) nesting in and near Ikh Nart Nature Reserve, Dornogobi Aimag, Mongolia. From 2003 till 2009, we monitored nesting pairs from incubation to fledging and compared nesting success for pairs nesting on rocks and trees. We captured chicks just prior to fledging to apply leg bands and wing tags. We also captured adults in June and attached solar-powered global positioning system (GPS)/satellite telemetry units, leg bands, and wing tags. We collected resighting data on marked birds opportunistically and telemetry data on tagged birds. We monitored 363 nesting pairs from 2003 to 2009. Most nesting failures occurred during the ~ 55 day incubation period. Overall, 50.9 % of nesting pairs raised a chick to fledgling. Nesting substrate (i.e., rock or tree) did not influence nesting success. Between 2006 and 2009 we received reports of sightings for 21 individual birds and on 37 occasions (n = 1 – 6 sightings/bird). Thirty three sightings (89%) came from South Korea between November and March, with other sightings in Mongolia, China, and Russia. We placed five GPS/satellite telemetry units on adult vultures in 2008 and 2009, but one did not work. We received 2,767 locations from the other four units through 2009. Adult vultures used large foraging areas, covering a mean minimum convex polygon home range of 27,025 ±11,922 SE km2, a mean 95% kernel home range of 4,953 ±1,596 SE km2, and a mean core home range (i.e., 50% kernel) of 526 ±168 SE km2. Our data suggest that only fledgling and juvenile birds disperse from Mongolia in late autumn/early winter, while adults remain in near their nesting sites, but we require more data. We do not know if most of our tagged birds travel to Korea or the large number of reported re-sightings there result from the stronger bird watching tradition in that country compared with other areas.