Skip to main content

The first documentation of a juvenile eastern imperial eagle (Aquila heliaca) with an unstreaked body Cover

.blurhash-client-img { display: none !important; }

The first documentation of a juvenile eastern imperial eagle (Aquila heliaca) with an unstreaked body

Volume 19 (2025): Issue 1 (October 2025)

By: Ivaylo Angelov

Open Access

|May 2025

Abstract

An extremely pale juvenile eastern imperial eagle (Aquila heliaca) without the typical dark streaking of the body was observed and photographed wintering in Oman. The bird presented an identification challenge and was initially identified as a tawny eagle (Aquila rapax). The possible overlap in the breeding distribution of both species is discussed, together with the possibility for natural hybridisation.

References

Ali S & Ripley SD 1978: Handbook of the birds of India and Pakistan. Volume 1, Divers to Hawks. Oxford University Press, Delhi.
Search in Google Scholar Back to article
BirdLife International 2024: Species factsheet: Eastern Imperial Eagle Aquila heliaca. Retrieved September 6, 2024 from https://datazone.birdlife.org/species/factsheet/eastern-imperial-eagle-aquila-heliaca on.
Search in Google Scholar Back to article
Clark WS 1992: The taxonomy of Steppe and Tawny Eagles, with criteria for separation of museum specimens and live eagles. Bulletin of the British Ornithologists’ Club 112(3): 150–157.
Search in Google Scholar Back to article
Corso A & Forsman D 1997: Hybrids between Black Kite and Common Buzzard. Alula 3: 44–45.
Search in Google Scholar Back to article
Corso A & Forsman D 2008: A hybrid Imperial Eagle × Golden Eagle in Romania. Birding World 21(6): 304–305.
Search in Google Scholar Back to article
Corso A & Monterosso G 2000: Eine unbeschriebene dunkle Variante des Baumfalken Falco subbuteo und ihre Unterscheidung vom Eleonorenfalken F. eleonorae. Limicola 14: 209–215.
Search in Google Scholar Back to article
Cramp S & Simmons KEL 1980: Handbook of the birds of Europe, the Middle East and North Africa. Vol. 2. Hawks to bustards. Oxford University Press, London.
Search in Google Scholar Back to article
Dombrovski VC 2023: Greater spotted eagles (Clanga clanga) pale morph “fulvescens” breeding during five consecutive years. Raptor Journal 17: 25–28. DOI: 10.2478/srj-2023-0003.
Search in Google Scholar Back to article
Donald CH 1952: The flight of eagles. Journal of the Bombay Natural History Society 50: 839–844.
Search in Google Scholar Back to article
Ellis DH 2024: Plumage features and quantification of molt in Golden Eagle. In: Ellis, D. H. & Bautista-Rodríguez, J. (eds.). The Golden Eagle around the world. Hancock House Publishers.
Search in Google Scholar Back to article
Ellis DH & Dunker H 2021: Pale plumage in Golden eagles from Scandinavia: extreme variants or a new color morph? Journal of Raptor Research, 55(1): 106–111.
Search in Google Scholar Back to article
Eriksen J & Porter R 2017: Birds of Oman. Christopher Helm, London.
Search in Google Scholar Back to article
Ferguson-Lees J, Christie DA, Franklin K, Mead D & Burton P 2001: Raptors of the World. Houghton Mifflin Company, Boston.
Search in Google Scholar Back to article
Fontanilles P, Luc F, Itty C & Bouillerce-Mirassou J 2022: Barthelemyi variant of the Gloden Eagle Aquila chrysaetos in the Pyrenees and Massif Central, France. Le Casseur d’os 22: 86–94.
Search in Google Scholar Back to article
Forsman, D 2016: Flight identification of raptors of Europe, North Africa and the Middle East. Helm Identification Guides, London.
Search in Google Scholar Back to article
Fowlie MK & Krüger O 2003: The evolution of plumage polymorphism in birds of prey and owls: the apostatic selection hypothesis revisited. Journal of Evolutionary Biology 16: 577–583.
Search in Google Scholar Back to article
Grimmett R, Inskipp C & Inskipp T 2011: Birds of the Indian subcontinent. Christopher Helm.
Search in Google Scholar Back to article
Helbig AJ, Kocum A, Seibold I & Braun MJ 2005: A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level. Molecular Phylogenetics and Evolution 35: 147–164.
Search in Google Scholar Back to article
Horváth M, Béres I, Özcan G, Juház T, Kovács A, Tatar B, Karyakin I, Schmidt M & Tavares J 2018: Breeding population surveys of Eastern Imperial Eagles and Steppe Eagles in Central Anatolia. VIII International Conference on the Conservation of the Eastern Imperial Eagle. Eagles of Palearctic: Study and Conservation Conference, Katun village, Altai Kray, Russia, 8 September 2018.
Search in Google Scholar Back to article
Hume AO 1890: Nests and eggs of Indian birds. Taylor and Francis, London.
Search in Google Scholar Back to article
Karyakin I 2018a: Distribution, population number and status of the Eastern Imperial Eagle in Russia and Kazakhstan. Raptors Conservation, suppl. 1: 115–117.
Search in Google Scholar Back to article
Karyakin I 2018b: Status of the Steppe eagle in the world: “white spots” in distribution, population numbers, ecology and threats. Raptors Conservation, suppl. 1: 81–84.
Search in Google Scholar Back to article
Karyakin I 2020: Breeding population structure of the Eastern Imperial Eagle. Raptors Conservation 41.
Search in Google Scholar Back to article
Karyakin I, Kovalenko AV & Zinevich LS 2016: The first record of case of the Imperial Eagle and the Steppe Eagle successful breeding in mixed pair in Western Kazakhstan and records of probable hybrids of these species in Russia and Kazakhstan. Raptors Conservation 32: 118–125.
Search in Google Scholar Back to article
Katzner T, Kochert M, Steenhof K, McIntyre C, Craig E & Miller T 2020: Golden Eagle (Aquila chrysaetos). 10.2173/bow.goleag.02.
Search in Google Scholar Back to article
Koning FJ 1976: Notes on the birds of prey in the Indus Valley. The journal of the Bombay Natural History Society 73: 448–455.
Search in Google Scholar Back to article
Lerner HRL & Mindell DP 2005: Phylogeny of eagles, Old World vultures, and other Accipitridae based on nuclear and mitochondrial DNA. Molecular Phylogenetics and Evolution 37: 327–346.
Search in Google Scholar Back to article
Macaulay Library: Retrieved March, 10, 2025 from: https://macaulaylibrary.org/asset/140876401
Search in Google Scholar Back to article
Martínez JE, Calvo JF, Jiménez-Franco MV, Zuberogoitia I & López-López P 2016: Colour morph does not predict brood size in the Booted Eagle. Ornis Fennica 93: 130–136.
Search in Google Scholar Back to article
Mateos RS & Morales LF 2016: Eastern Imperial Eagle in India. Retrieved March, 10, 2025 from: https://raptorsoftheworld.org/2016/01/02/aguila-imperial-oriental-en-india-2/.
Search in Google Scholar Back to article
McGrady MJ, Schmidt M, Andersen GE, Meyburg C, Väli Ü, Al Lamki F & Meyburg B-U 2021: Movements of a male greater spotted eagle (Clanga clanga) during its 2nd and 3rd calendar years. Raptor Journal 15: 1–15. DOI: 10.2478/srj-2021-0001.
Search in Google Scholar Back to article
Meyburg B, Angelov I & Azar S 2020: A corridor of soaring bird migration in Lebanon on the Eastern Mediterranean flyway. Sandgrouse 42: 46–58.
Search in Google Scholar Back to article
Naoroji R 2011: Birds of prey of the Indian subcontinent. Om Books International, New Delhi, India.
Search in Google Scholar Back to article
Pröhl T & Baumgart W 2012: An Überwinterungsplätzen des Steppenadlers (Aquila nipalensis) und anderer großer aasverwertender Greifvögel im Oman. Greifvögel und Falknerei 2012: 47–72.
Search in Google Scholar Back to article
Ram M, Gadhavi D, Sahu A, Srivastava N, Rather TA, Modi V, Patel A, Jhala L, Zala Y & Jhala D 2024: Aspects of movement ecology and habitat use of migratory raptors using satellite telemetry from India to Central Asia. Birds 5: 487–508.
Search in Google Scholar Back to article
Ram M, Sahu A, Tikadar S, Gadhavi D, Rather TA, Jhala L & Zala Y 2022: Home ranges and migration routes of four threatened raptors in Central Asia: preliminary results. Birds 3: 293–305.
Search in Google Scholar Back to article
Scott D 2008: Rare Birds in Iran in the Late 1960s and 1970s. Podoces 2008, 3(1/2): 1–30.
Search in Google Scholar Back to article
Sternalski A, Mougeot F & Bretagnolle V 2012: Adaptive significance of permanent female mimicry in a bird of prey. Biology Letters 8: 167–170.
Search in Google Scholar Back to article
Svenson L, Mullarney K, Zetterström D, Christie DA 2009: Collins Bird Guide. 2nd Edition, HarperCollins, London.
Search in Google Scholar Back to article
Väli Ü, Dombrovski V, Treinys R, Bergmanis U, Daróczi S, Dravecky M, Ivanovski V, Lontkowski J, Maciorowski G, Meyburg B-U, Mizera T, Zeitz R & Ellegren H 2010: Widespread hybridization between the Greater Spotted Eagle Aquila clanga and the Lesser Spotted Eagle Aquila pomarina (Aves: Accipitriformes) in Europe. Biological Journal of the Linnean Society 100: 725–736. DOI: 10.1111/j.1095-8312.2010.01455.x.
Search in Google Scholar Back to article

Articles in this issue

DOI: https://doi.org/10.2478/srj-2025-0005 | Journal eISSN: 2644-5247 | Journal ISSN: 1337-3463

Journal RSS Feed

Language: English

Page range: 39 - 43

Submitted on: Mar 15, 2025

|

Accepted on: Apr 17, 2025

|

Published on: May 24, 2025

Published by: Raptor Protection of Slovakia

In partnership with: Paradigm Publishing Services

Publication frequency: 1 issue per year

Keywords:

raptor identification,

Related subjects:

© 2025 Ivaylo Angelov, published by Raptor Protection of Slovakia
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Volume 19 (2025): Issue 1 (October 2025)

Previous article