Griffon Vulture Survival Remains Exceptionally High Four Decades After Reintroduction
Long-term monitoring in the Grands Causses, in France, shows consistently strong survival rates despite growing populations and expanding human pressures
Forty years of data reveal a conservation success
Four decades after Griffon Vultures were reintroduced to the limestone valleys of the Grands Causses, survival remains impressively high across all age groups. The new analysis, based on 1,506 locally born birds monitored from 1982 to 2021, confirms that juveniles, immatures and adults all show strong annual survival, supporting the long-term stability of this now-thriving population. Juveniles survived at around two-thirds per year, immatures at just over nine in ten, and adults at roughly 94 per cent.
The findings illustrate how sustained management, abundant food and regular monitoring have enabled the population to grow from just 61 released birds in the early 1980s to more than 1,000 breeding pairs in 2024.
No sign of density pressures or major human impacts
Despite rapid expansion of the colony over the past 40 years, researchers found no clear evidence that rising numbers have yet reduced survival. Juvenile survival showed small fluctuations, but none strong enough to indicate emerging density dependence.
Importantly, the study detected no major survival impacts from growing human pressures. While more than 50 wind turbine collisions have been recorded regionally in recent years, these incidents did not translate into measurable declines in survival across the wider population. Feeding stations, meanwhile, may have helped buffer potential pressures by keeping competition low and food accessible.
Understanding movement is a priority for future monitoring
Although adult survival remains high and stable, the patterns observed in younger birds suggest that dispersal deserves increasing attention. Immature birds travel widely, making them more vulnerable to collisions and other local threats. A slight imbalance between males and females in immature survival hints that one sex may disperse more readily, though further study is needed.
With wind turbines expanding into areas previously outside the colony’s main foraging grounds, the authors highlight the importance of tracking immature birds more closely to understand how exploration routes may expose them to new risks.
Long-term monitoring remains essential
The study reinforces the value of sustained, consistent monitoring over decades. Ringing, resighting and analysis of individual life histories revealed how marking type, detection probability and feeding-station distribution all shape the quality of survival estimates.
As the population continues to grow and human infrastructure expands, long-term data will be vital for detecting future change, anticipating new pressures and ensuring the colony’s continued success.
November 2025
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