Seasonal and age-specific dynamics of the Griffon Vulture’s home range and movements in the Eastern Rhodopes

Abstract

The spatial ecology of the Eurasian Griffon Vulture (Gyps fulvus) has been a subject of scientific interest for long due to its conservation status, critical ecosystem role, gregarious lifestyle and complex foraging behavior. The trans-border Eastern Rhodope Mountain in Bulgaria and Greece holds an increasing population of the species and one of the largest on the Balkan Peninsula. We used high-frequency GPS data from 13 Griffon Vultures from this population to study their movements, home range size and its seasonal or age specific dynamics. The overall foraging home range (95% kernel) was 3,204 km2 and the core area of activity (50% kernel) was 256.5 km2. We found high seasonal variation of the home range size. Vultures were foraging over larger areas in the summer and spring but their activity was limited to four times smaller areas in winter. We found no age specific variation in the home range sizes but the non-adult vultures showed tendency to conduct exploratory movements far from the breeding colony. Our results can be used for planning conservation efforts in the areas of high importance for the species.

Insights on the best release strategy from post-release movements and mortality patterns in an avian scavenger

“…Other authors, such as Arkumarev et al. 51 in Bulgaria (overall foraging home range 3,204 km 2 , 95% kernel – 13 GPS-tracked wild Griffon vultures, both adults and immatures) and Morant et al. 52 in Spain (annual 5,027 ± 2,123 km 2 , monthly 4,889 ± 1,753 km 2 , KDE 95% - 127 GPS-tracked Griffon vultures), reported even larger values.…”

“… 50 Crete 1,560 ± 140 Mean, KDE 95%, all individuals and seasons pooled Adults and immatures Arkumarev et al. 51 Bulgaria 3,204 95% kernel, overall foraging range, Minimum Convex Polygon (MCP) Adults and immatures Peshev et al. 45 Bulgaria, Greece, North Macedonia 1,431.22 ± 1,472.12 dynamic Brownian bridge movement model (dBBMM), mean 95% for all individuals Adults and immatures Morant et al.…”

A long‐lasting, distant journey of a male griffon vulture informs on the success of differential parental investment

“…During the breeding season, breeding individuals have restrictions on foraging movements imposed by the need to return to the nest with a variable frequency that depends on the phenological state of the reproduction process (central place foraging strategy; Carrete & Donázar, 2005). These constraints are reduced or disappear when breeding ends or fails and individuals may relax their territoriality and even temporally abandon breeding areas (Arkumarev, Dobrev, et al, 2021; Genero et al, 2020).…”

Large‐scale movement patterns in a social vulture are influenced by seasonality, sex, and breeding region

“…Individuals forage over vast areas to satisfy their energetic requirements (e.g., ranging annually from 1560 to 4233 km 2 , Fluhr et al, 2021 ; Monsarrat et al, 2013 ; Nathan et al, 2012 ; Xirouchakis et al, 2021 ), frequently congregating around both wild and domestic ungulate carcasses (Cortés‐Avizanda et al, 2010 , 2012 but see also Delgado‐González et al, 2022 ). Although information exists on Griffon vulture movement ranges (Arkumarev et al, 2021 ; Arrondo et al, 2018 ; Arrondo, Sanz‐Aguilar, et al, 2020 ; Fluhr et al, 2021 ; García‐Ripollés et al, 2011 ; Harel et al, 2017 ; Spiegel et al, 2013 , 2015 ; Xirouchakis et al, 2021 ; Xirouchakis & Mylonas, 2007 ; Zuberogoitia et al, 2013 ), virtually nothing is known about the spatio‐temporal variation in the movement patterns of adult individuals, or about the factors (e.g., sex, breeding region) governing the spatial ecology and home‐range fidelity of this species from a mechanistic perspective.…”