Harrop, A. H . J. 2004. The ‘North American’ Peregrine Falcon in Britain. A Review on behalf of the British Ornithologists’ Union Records Committee. Brit. Birds 97: 130-133. Crouzier, P, Duquet, M, Noël, F & CHN 1999. Le Choucas des tours Corvus monedula de la subspecies orientale soemmerringii en France: le point après 3 ans d’enquête. Ornithos 6: 178-182. Vireonidae, vireos, including Cyclarhis peppershrikes, Vireolanius shrike-vireos and Pteruthius shrike-babblers

Shrikes of the World (Helm Identification Guides) - Goodreads

Golawski, A.; Mroz, E.; Golawska, S. (2020). "The function of food storing in shrikes: the importance of larders for the condition of females and during inclement weather". The European Zoological Journal. 87 (1): 282–293. doi: 10.1080/24750263.2020.1769208. ISSN 2475-0263. Nominate apus is a very common breeder in Britain. The subspecies pekinensis is not on the British List although it is a potential vagrant and has occasionally been suspected (Kehoe 2006). This book is the first monograph in English on the 34 shrike species distributed across Africa, Eurasia and North America. These birds have attracted the attention of ornithologists for a long time, mainly because of their predatory nature and the methods which they use to dispatch their prey. In the book, the most important information on shrikes of the World is summarized, much of which has accumulated in the ornithological literature and obtained by the author himself. These voluminous empirical data are also used by the author in an attempt to reconstruct the evolutionary history of the group at different stages of its phylogenesis, from the early origins of the family Laniidae, presumably in Africa, through the secondary expansion of species across Eurasia and into the New World. Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. p. 219. ISBN 978-1-4081-2501-4. Cramp, S. et al. 1980. The Birds of the Western Palearctic. Vol. 2. Oxford University Press, Oxford.Claims of pekinensis are welcomed if accompanied by detailed notes and good photographs but only a ringing recovery from the core range is likely to confirm this subspecies in a vagrant context. ( updated Dec 2017 AMS).

Shrikes of the World - Norbert Lefranc - Google Books Shrikes of the World - Norbert Lefranc - Google Books

The subspecies aesalon is a regular breeder and winter visitor in Britain, subaesalon occurring as a migrant and in winter. An old pre-BBRC specimen record of nominate columbarius has been reviewed and rejected but the subspecies has now been readmitted to the British List on the basis of a bird in Caithness in February 2018 . There is also a record of this subspecies from Ireland in September 2000 ( http://www.irbc.ie/reports/irbr/2007_IRBR.pdf). The subspecies pallidus has also been claimed in Britain. Norbert Lefranc is a French ornithologist specialising in the ecology of shrikes. He has travelled all over the world in search of shrikes and other birds, publishing many papers and four books, including Les Pies-grièches d'Europe, d'Afrique du Nord et du Moyen-Orient (1993) and the first edition of the present book (1997). He worked as a biodiversity officer for the Ministry of Ecology in the 'Grand Est'. Now retired, he spends his time contributing to research and conservation actions led by NGOs, particularly by the Société d'Etudes Ornithologiques de France (SEOF) and the Ligue pour la Protection des Oiseaux (LPO/Birdlife France). Claims of pinetorum should be accompanied by biometrics. Details of a ringed bird would of course provide additional evidence. ( updated Dec 2017 AMS). The identification of pekinensis is not straightforward as it needs to be distinguished not just from nominate apus but also from three subspecies of Pallid Swift A. pallidus. Adult pekinensis may suggest a dark Pallid Swift with a relatively dark body and underwing coverts contrasting with a pale, ‘silvery’ innerwing and a large pale throat patch but it also shows a very clearly-defined white forehead and the rear body and tail structure of a Swift. The identification of juveniles is much more problematic. Firm identification features are not known, and field identification is probably impossible even with good views and photographs. Of course the difficulty of obtaining good views, the dramatically shifting appearance of plumage according to the light conditions and the difficulty of assessing structure and plumage even in good photographs all further complicate the identification of these swifts.a b Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (July 2023). "Shrikes, vireos, shrike-babblers". IOC World Bird List Version 13.2. International Ornithologists' Union . Retrieved 23 July 2023.