Trends in territory occupancy, distribution and density of Bearded Vultures in southern Africa.

Trends in territory occupancy, distribution and density of the Bearded Vulture Gypaetus barbatus meridionalis in southern Africa, SONJA C. KRÜGER , DAVID G. ALLAN , ANDREW R. JENKINS and ARJUN AMA

Summary

Lammergeier_-_Bearded_VultuTerritory occupancy, distribution and density of the isolated Bearded Vulture Gypaetus barbatus meridionalis population in the Maloti-Drakensberg mountains of southern Africa were assessed between two time periods – former (1960–1999) and current (2000–2012) – to identify population trends. Overall, 190 territories were recorded of which 109 are currently occupied. The number of occupied breeding territories decreased by a minimum of 32% and a maximum of 51% over the past five decades. Territories located on the periphery of the breeding range were more likely to be abandoned than those in the core. The current population is estimated at a minimum of 352 and a maximum of 390 individuals. The breeding range decreased by 27%, restricting the birds to an estimated area of occupancy of 28,125 km 2 . Breeding densities also decreased by 20%, declining from 4.9 to 3.9 pairs/1,000 km 2 . In both periods, higher densities were recorded in the core of the range. Nests were located about 9.0 km apart, a slight increase from the 7.7 km recorded formerly. Inter-nest distances increased with distance from the core range. Further studies are required to ascertain whether productivity or survival is limiting population growth, and whether anthropogenic influences are resulting in the abandonment of territories in the periphery of the range and the subsequent decline in numbers.

Introduction

In Africa, large reductions in vulture numbers have occurred in recent decades in areas where these birds were previously abundant, to the extent that some populations have either become locally extinct or are found only in protected areas (Ogada et al. 2012 ). In keeping with these trends, Bearded Vulture Gypaetus barbatus populations are declining throughout much of the species’ range (Margalida et al. 2008a , BirdLife International 2012b), and have been since as early as the mid-19 th century, with some populations nearing extinction by the mid-20 th century (Mingozzi and Estève 1997 ).

The above Summary and introduction are each part of a detailed Scientific paper highlighting the density, distribution and decline of the Bearded Vulture in southern Africa. We have been given permission by one of the authors to publish this interesting account of one of Africa’s rarest members of the vulture family. We trust that some of our followers who may be interested will take the time to read the paper HERE.

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