October 2023 was the 31st time in which white backed vultures in the De Beers-owned Dronfield game farm outside Kimberley, were monitored and fledglings tagged under the leadership of Angus Anthony of the Dronfield Vulture Monitoring Project.
Anthony recently released his report with this year’s findings and observations.
During the monitoring, he was assisted by experts from De Beers, the Hawk Conservation Trust and the Gauntlet Bird of Prey Eagle and Vulture Park in England, BirdLife South Africa, SANparks, Endangered Wildlife Trust, KZN Wildlife, the Sociable Weaver Project, Puy du Fou in France, and volunteers from Kimberley who caught fledglings and helped capture vital statistics such as weight and wing length, as well as ring and tag birds.
The teams also monitored birds on Samaira, east of Dronfield) and Waterkolk, at the Rooiport Nature Reserve.
Some 167 active nests were checked and 76 fledglings ringed and wings tagged. Dronfield had 122 active nests, while Samaria had 18 and Waterkolk 27.
“The results were 96 fledglings in nests of which 76 were ringed, the other 20 either were too small to ring or the nests could not be accessed. The percentage of chicks fledged was the highest since 2019. Egg failures remain the highest mortality factor, with this year being above the 14-year average”
He says causes could be predation by pied crows, vervet monkeys, giant eagle owls or poisoning of both or one of the adult parents.
“One of the highlights was that we could capture 20 free flying vultures to attach wing tags or replace old ones for the first time,” Anthony says. Some birds were fitted with GPS transmitters and blood samples were taken.
“We found four adults vultures with old colour ringed birds, which researchers last used in 2003. It indicted that these birds were at least 20 years old, with one possibly 27 years old.”
It was also interesting that more vultures than last year that were ringed and tagged at SANparks’ Mokala game reserve some 80 km outside of Kimberley, were nesting in Dronfield.
