Poisoning and re-introduction of the Griffon Vulture <i>Gyps fulvus</i> in Kresna Gorge, Bulgaria 2017

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

“…This basic area near the supplementary feeding site at the Uvac colony (with a distance of less than three km) also includes common roosting sites of Griffon vultures, and in its proximity was also the birth nest of this particular bird, which it often visited. We identified three additional core areas near the Mileševka colony and feeding site, the Radoinja colony and the Pešter plateau; this is in concordance with findings that vulture feeding sites and the most commonly used roosting sites are usually within 15 km of each other, and that the covered area is in the radius of 14-15 km around the main colony [2,27,28,32].…”

“…Foraging and home ranges of the Griffon vultures are expected to vary between different seasons, as shown in [32], with travel distance in the spring-summer period being about three times longer than during the autumn-winter period. Our study showed similar findings with the larger foraging ranges in spring and summer during all study periods.…”

“…We calculated the foraging range using the minimum convex polygon (MCP), encompassing all location fixes for a specific season/year. Since the MCP can be greatly influenced by a single outlying data point, we also used the kernel density (KD) approach to calculate the home range (95% isopleths), core area (75% isopleths) and basic area (50% isopleths) [32,36,38,39]. All parameters were calculated separately for each year, the season of each year, and for all fixes combined across all years.…”

“…Satellite telemetry has proved to be a highly effective method for investigating the movement ecology of different raptor species, including vultures [21,[29][30][31]. It has provided assessments of home ranges and movements throughout the species distribution range, with studies conducted in the Caucasus [21], Spain [2] and Bulgaria [32]. GPS tracking provides precise data on the home range, dispersal and migration of the birds.…”

“…GPS tracking provides precise data on the home range, dispersal and migration of the birds. It allows for the identification of the most frequently used foraging areas, as well as the detection of previously unknown roosting and breeding sites [32]. Information on the ranging behavior and spatial parameters is important for the long-term conservation of vulture species [2].…”