Data on territory occupancy and breeding success for 87 different territories of the Endangered Egyptian Vulture Neophron percnopterus in the Balkans were correlated with 48 different environmental variables to understand the relative influence of various factors on population declines. The analysis included 405 breeding events between 2003 and 2015, and results have just been published in Journal of Ornithology.
Overall territory occupancy rate was 69% and the mean productivity per occupied territory was 0.80 fledglings, but no single variable was influential in explaining variation in territory occupancy and breeding success in Bulgaria and Greece – on the contrary, many of them had a small effect. Further, when testing if the models were transferrable to the territories in Macedonia, it was found they were unsuccessful in predicting occupancy or breeding success, suggesting the most influential factors vary geographically.
This suggests that management focussing on a small number of environmental variables is unlikely to be effective in slowing the decline of Egyptian Vultures on the Balkan Peninsula.
The authors recommend that in the short term the reduction of adult mortality through the enforcement of anti-poison laws, and in the long term the adoption of large-scale landscape conservation programs that retain or restore historical small-scale farming practices may benefit vultures and other biodiversity.
You can download the paper below.