Supplementary Feeding and Changes in Breeding-Site Occupancy of Griffon Vultures Gyps fulvus within the King Salman Bin Abdulaziz Royal Natural Reserve, Saudi Arabia
This study assessed Griffon Vulture Gyps fulvus breeding-site occupancy before and after the introduction of supplementary feeding in the King Salman Bin Abdulaziz Royal Natural Reserve, northern Saudi Arabia. Fifty-seven cliff sites were surveyed in 2024 and resurveyed in 2025 after feeding stations operated during the breeding period. Occupancy increased from 56.1% to 75.4%, with colonization of inactive sites exceeding losses. Occupancy was highest in the zone where feeding-station use was greatest, although this zone also had the highest pre-feeding occupancy. Across the survey area, 82 active nests were recorded in 2025. The results suggest that carefully managed feeding using veterinary-screened carcasses may support breeding-site use, but the before-and-after design without an independent unfed control area limits causal inference, and longer-term monitoring is needed to distinguish sustained population growth from short-term redistribution.
References
[1]
Moreno-Opo, R. and Margalida, A. (2014) Conservation of the Cinereous Vulture aegypius Monachus in Spain (1966-2011): A Bibliometric Review of Threats, Research and Adaptive Management. Bird Conservation International, 24, 178-191. https://doi.org/10.1017/s0959270913000427
[2]
Boland, C., et al. (2020) The Birds of Saudi Arabia. Saudi Aramco.
[3]
Shobrak, M. (2012) The Decline of the Griffon Vulture in Saudi Arabia. Phoenix, 28, 7-11.
[4]
Jennings, M.C. (2010) Atlas of the Breeding Birds of Arabia. Vol. 25, King Abdulaziz City for Science and Technology.
[5]
Shobrak, M. (2003) Vultures in Saudi Arabia. Vulture News, 48, 20-23.
[6]
Babbington, J.E.M. (2019) First Fully Documented Record of Rüppell’s Vulture Gyps Rueppelli for Saudi Arabia and the Arabian Peninsula. Sandgrouse, 41, 205-210.
[7]
Jennings, M.C., et al. (2009) Wintering Birds in Northern Saudi Arabia: February 2009 (ABBA Survey 40). MC Jennings.
[8]
Al Zoubi, M.Y., Shobrak, M., Alqanoon, F., et al. (2023) Notes on the Breeding of the Eurasian Griffon Vulture Gyps Fulvus in Saudi Arabia. Sandgrouse, 45, 70-78.
[9]
Shobrak, M., Alasmari, S., Alqthami, A., et al. (2020) Congregations and Threats of Migratory Egyptian Vultures Neophron Percnopterus along the Southwest Coast of Saudi Arabia. Sandgrouse, 42, 248-258.
[10]
Hatem, A.S., Tamer, K., Hamdan, A. and Shaykah, A. (2023) Medicinal Plants Diversity at King Salman Bin Abdulaziz Royal Natural Reserve in Saudi Arabia and Their Conservation Management. Journal of Medicinal Plants Research, 17, 292-304. https://doi.org/10.5897/jmpr2023.7317
[11]
Al-Hasan, H.B.A. (2006) Wild Plants in the Rangelands of Northern Saudi Arabia: Illustrated Field Guide. National Center for Camel and Range Research.
[12]
Gilbert, M., Watson, R.T., Ahmed, S., Asim, M. and Johnson, J.A. (2007) Vulture Restaurants and Their Role in Reducing Diclofenac Exposure in Asian Vultures. Bird Conservation International, 17, 63-77. https://doi.org/10.1017/s0959270906000621
[13]
Università degli Studi di Sassari (2024) Technical Manual on the Feeding Stations (Action E.2), in LIFE SAFE for VULTURES Project (LIFE19 NAT/IT/000732).
[14]
Arkumarev, V., Dobrev, D., Stamenov, A., Terziev, N., Delchev, A. and Stoychev, S. (2021) Seasonal Dynamics in the Exploitation of Natural Carcasses and Supplementary Feeding Stations by a Top Avian Scavenger. Journal of Ornithology, 162, 723-735. https://doi.org/10.1007/s10336-021-01865-1
[15]
Moreno-Opo, R., Trujillano, A. and Margalida, A. (2015) Optimization of Supplementary Feeding Programs for European Vultures Depends on Environmental and Management Factors. Ecosphere, 6, 1-15. https://doi.org/10.1890/es15-00009.1
[16]
Cortés-Avizanda, A., Carrete, M. and Donázar, J.A. (2010) Managing Supplementary Feeding for Avian Scavengers: Guidelines for Optimal Design Using Ecological Criteria. Biological Conservation, 143, 1707-1715. https://doi.org/10.1016/j.biocon.2010.04.016
[17]
Dobrev, D., Tsiakiris, R., Skartsi, T., Dobrev, V., Arkumarev, V., Stara, K., et al. (2022) Long-Term Size and Range Changes of the Griffon Vulture Gypsfulvus Population in the Balkans: A Review. Bird Conservation International, 32, 206-221. https://doi.org/10.1017/s0959270921000198
[18]
Moreno-Opo, R., Trujillano, A., Arredondo, á., González, L.M. and Margalida, A. (2015) Manipulating Size, Amount and Appearance of Food Inputs to Optimize Supplementary Feeding Programs for European Vultures. Biological Conservation, 181, 27-35. https://doi.org/10.1016/j.biocon.2014.10.022
[19]
Moreno‐Opo, R., Margalida, A., Arredondo, á., Guil, F., Martín, M., Higuero, R., et al. (2010) Factors Influencing the Presence of the Cinereous Vulture Aegypius Monachus at Carcasses: Food Preferences and Implications for the Management of Supplementary Feeding Sites. Wildlife Biology, 16, 25-34. https://doi.org/10.2981/09-037
[20]
Reznikov, K., Efrat, R., Berger-Tal, O. and Sapir, N. (2024) The Spatiotemporal Properties of Artificial Feeding Schemes Influence the Post-Fledging Movement of Egyptian Vultures. Ornithological Applications, 126, duae010. https://doi.org/10.1093/ornithapp/duae010
[21]
Tsiakiris, R., Halley, J.M., Stara, K., Monokrousos, N., Karyou, C., Kassinis, N., et al. (2021) Models of Poisoning Effects on Vulture Populations Show That Small but Frequent Episodes Have a Larger Effect than Large but Rare Ones. Web Ecology, 21, 79-93. https://doi.org/10.5194/we-21-79-2021
[22]
Buij, R., Richards, N.L., Rooney, E., Ruddock, M., Horváth, M., Krone, O., et al. (2025) Raptor Poisoning in Europe between 1996 and 2016: A Continental Assessment of the Most Affected Species and the Most Used Poisons. Journal of Raptor Research, 59, 1-19. https://doi.org/10.3356/jrr2373
[23]
Cortés‐Avizanda, A., Blanco, G., DeVault, T.L., Markandya, A., Virani, M.Z., Brandt, J., et al. (2016) Supplementary Feeding and Endangered Avian Scavengers: Benefits, Caveats, and Controversies. Frontiers in Ecology and the Environment, 14, 191-199. https://doi.org/10.1002/fee.1257
[24]
Botha, A.J., et al. (2017) Multi-Species Action Plan to Conserve African-Eurasian Vultures. Coordinating Unit of the CMS Raptors MOU.
[25]
Oliva-Vidal, P., Hernández-Matías, A., García, D., Colomer, M.à., Real, J. and Margalida, A. (2022) Griffon Vultures, Livestock and Farmers: Unraveling a Complex Socio-Economic Ecological Conflict from a Conservation Perspective. Biological Conservation, 272, Article 109664. https://doi.org/10.1016/j.biocon.2022.109664
