The bearded vulture reintroduction project in the Alps is one of the most successful and celebrated wildlife comeback stories in Europe. Following extinction in the beginning of the 20th century, the species started to be reintroduced in 1986, and today there are 40+ established territorial pairs. The population is slowly increasing in France, Switzerland, Italy and Austria.
However, the exact population size is not known – as bearded vultures take at least 5 years to mature sexually, there are lots of immatures flying around. The total population of the Alps is estimated at 200-250 birds.
In order to try to arrive at a better estimate of the total population size, every year for the last 11 years bearded vulture researchers and enthusiasts attempt a one day simultaneous survey across the alpine chain, to count and identify as many bearded vultures as possible – an exercise that helps with the regional monitoring efforts, and ultimately will contribute to accurate population demography figures.
Last year´s census happened between the 8th and 16th of October. Last year the monitoring network was expanded to the eastern parts of the Pyrenees to detect possible migration between the Alpine and Pyrenean bearded vulture populations.
More than 770 observers occupied 528 observation sites during that week in October and reported almost 500 bearded vulture observations. According to the assessment of the regional coordinators, 149 to 178 different bearded vulture individuals have been observed during the focal day (2016/10/08). If we include individuals that have not been observed but are expected to be present in the region (territorial birds, in some exceptional cases also their fledglings, GPS-tagged birds etc.) the estimates for the global population range between 172 and 218 birds, with considerable regional differences.
Most of the observed bearded vultures were adults (52%), followed by immatures (19%), juveniles (17%), subadults (8%) and there were <5% of the birds where age determination was not possible. Furthermore, it was possible to identify 88 birds on an individual level, thus providing us valuable information on the life history of these birds.
Comparing this year´s estimates with the predictions from the demographic model developed in 2009 the volunteers could observe between 61% and 72% of the theoretical population. These estimates are similar to last year's results under similar weather conditions.
The VCF would like to thank all these hundreds of observers who have given their time to track this most charismatic species across Europe’s largest mountain chain. The International Observation Day is a momentous effort, requiring a lot of effort to coordinate, but it also provides vulture enthusiasts with a great day out, and an opportunity to engage with fellow colleagues who share the same passion.
Ref. Schaub, M., Zink, R., Beissmann, H., Sarrazin, F., & Arlettaz, R. (2009). When to end releases in reintroduction programmes: demographic rates and population viability analysis of bearded vultures in the Alps. Journal of Applied Ecology, 46(1), 92-100.