While the European population of this bird of prey is generally declining, that of Catalonia has been increasing for two decades – answers to this may prove essential to revert the conservation situation with this endangered species
Egyptian vultures are still declining across most of its vast range, and thus in 2007 it was classified as globally Endangered by IUCN. Even in Spain, its largest European stronghold (50% of the global population), where there are between 1320-1480 pairs, the species suffered a marked decline over the last twenty years (around 25%), and has disappeared from several areas of the Iberian Peninsula.
Interestingly, in Catalonia the species is increasing fast - from 1 pair in 1988 to the 28 pairs currently observed in one particular study area - the total for the autonomous regions reaches 70-80 pairs. The species has now recolonized most if its historical range in the region, but also actually occupied areas where it did not occur before.
Ornithologists of the Department of Animal Biology of the University of Barcelona have been studying and monitoring the species since 2012, and confirm that this population growth is still continuing: In 2015 a new occupied territory was located, and half of the breeding pairs that have bred with success have raised two chicks each. In total, last year, 21 chicks fledged, from the 23 breeding pairs that have started to breed – see http://www.ub.edu/aligaperdiguera/EEAPang/actual69.html for the latest results from the monitoring programme.
To try to understand the reasons for this very favourable trend, the researchers from the University of Barcelona developed population models with several demographic parameters (rate of increase of the population, survival, productivity of individuals, etc.) and concluded that the key factor to explain the observed trend is the adult survival rate, which is much higher in Catalonia than in other areas of the Iberian Peninsula.
In Catalonia the use of poison is lower than elsewhere in Spain, which has certainly contributed for a much reduced adult mortality. Immigration from other populations also played a key role in this growth.
You can download their paper below.
Photo Bruno Berthemy-VCF