Spatial ecology of non-breeding Eurasian Griffon VulturesGyps fulvusin relation to natural and artificial food availability

Abstract

Capsule: The movements and spatial ecology of non-breeding Eurasian Griffon Vultures Gyps fulvus in northern Italy, Croatia and Austria do not seem to be affected by feeding station use. Aims: The purpose of this study was to assess how the creation of a feeding station at the Riserva Naturale Regionale del Lago di Cornino (Forgaria nel Friuli, northeast Italy) during the 1980s might have affected the spatial and behavioural ecology of the Eurasian Griffon Vulture. Methods: Using global positioning system (GPS) satellite tracking, we studied movements of nine non-breeding Eurasian Griffon Vultures within the Riserva Naturale Regionale del Lago di Cornino in Italy, the Hohe Tauern in Austria and the Kvarner Gulf in Croatia. Results: Both the average foraging range size and the time spent by the birds in Italy were comparable to those recorded in Croatia and Austria, where the vultures depend on unpredictable food resources. A significant difference in terms of foraging range size was recorded among seasons. In winter it seems to be smaller as a consequence of reduced movements performed by the individuals due to harsh climate conditions. Conclusions: Our results suggest that the creation of a feeding station in Forgaria does not seem to have affected the spatial ecology of the Eurasian Griffon Vulture. However, due to the limited sample size and the young age of the individuals monitored, which have a long dispersal period, the findings presented should be considered as preliminary. Further research needs to be implemented to inform decisions regarding the management of supplementary feeding stations to promote the recovery and conservation of scavenger species, particularly in areas in which they have declined massively.

First description of movement and ranging behavior of the Griffon vulture (Gyps fulvus) from Serbia using GPS satellite tracking

“…In Italy, the spring core area (equivalent to the basic area in our study) was significantly smaller than in summer [49], while in Croatia the largest core area was recorded during the autumn, but no significant difference between seasons was detected [49]. These results also suggest that vultures tended to stay more within their respective areas in autumn than in spring and/or summer when flight conditions are less favorable [49,54]. Our results are in accordance with studies from Bulgaria [32] and France [45], as we also observed smaller foraging ranges, home ranges and basic areas during winter and autumn.…”

“…Smaller basic, core, home and foraging ranges were also noticeable during the autumn of 2013 and winter of 2013/2014. In Italy, the spring core area (equivalent to the basic area in our study) was significantly smaller than in summer [49], while in Croatia the largest core area was recorded during the autumn, but no significant difference between seasons was detected [49]. These results also suggest that vultures tended to stay more within their respective areas in autumn than in spring and/or summer when flight conditions are less favorable [49,54].…”

“…These areas are centers of traditional and contemporary livestock raising and pasturing in Serbia [48]. Similar foraging behavior was found in [2,49], where vultures ranged mainly in areas where similar traditional stock raising and pasturing practices are common. Our results showed that the bird relied on and regularly visited supplementary feeding sites, especially the one at the Uvac colony.…”

New insight into spatial ecology of Griffon Vulture (Gyps fulvus) on the Balkans provides opportunity for focusing conservation actions for a threatened social scavenger

“…It is shared amongst Croatia, Italy, Slovenia and Austria (see Fig. 4 ) with several centres - Lago di Cornino Nature Reserve ( N46.22, E13.02 , Italy), where Griffon Vulture has been re-introduced and started breeding in the 1990s ( Mihelic and Genero 2005 ), the Kvarner Archipelago (North Adriatic) - islands of Cres, Krk, Plavnik, Prvich and Pag ( N44.98, E14.40 , Croatia), Hohe Tauern National Park ( N47.14, E12.85 , Austria) with some extentions towards the Triglav National Park ( N46.36, E13.55 , Slovenia) - also reported by Mihelic and Genero (2005) and Genero et al (2020) . The 50% core area of the zone is 291.37 km 2 and the 95% home range is calculated at 6,803.04 km 2 (based on the location data of three tracked birds).…”

“…comm. ), but also published studies ( Genero et al 2020 ), additional research is necessary. A vulture feeding site was operating regularly in Lago di Cornino National Park, Italy and occasionally on the Island of Cres, Croatia, throughout the study period.…”