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

Volen Arkumarev,Atanas Delchev,Stoycho Stoychev,Anton Stamenov,Dobromir Dobrev

doi:10.2478/orhu-2021-0021

Volen Arkumarev, Atanas Delchev + Show 3 more

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https://doi.org/10.2478/orhu-2021-0021

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Abstract

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.

Highlights

The Eurasian Griffon Vulture (Gyps fulvus) is a large long-lived scavenger with a breeding distribution extending from Portugal in the west to the Himalayas in the east (Ferguson Lees & Christie 2001)
We found that the core of the home range encompasses the species breeding sites along the Arda river valley in Bulgaria, the central feeding station and two small feeding stations, and the Boynik ridge
The Griffon Vultures frequently visited the central feeding station near the village of Dadia, which is managed by the Management Body of Dadia-Soufli-Lefkimi Forest National Park (DSLFNP)

Summary

Introduction

The Eurasian Griffon Vulture (Gyps fulvus) is a large long-lived scavenger with a breeding distribution extending from Portugal in the west to the Himalayas in the east (Ferguson Lees & Christie 2001). It is listed as ‘Least Concern’ by the IUCN and is the most common vulture species in Europe (BirdLife International 2021). Its population in Bulgaria has steadily increased as a result of intensive conservation actions and successful reintroduction programs (Demerdzhiev et al 2014, Kmetova-Biro 2021, Dobrev et al 2021a). The adult and immature Griffon Vultures are mostly resident, while some juveniles are migratory and winter in the Middle East and Africa (del Hoyo et al 1994, McGrady & Gavashelishvili 2006, Arkumarev et al 2019)

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