British Birds

July 2007

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This Month's Contents

	392 The changing status of Balearic Shearwater in northwest European waters Russell B. Wynn and Pierre Yesou
	407 Identification of 'black-and-white' storm-petrels of the North Atlantic Robert L. Flood and Bryan Thomas
	443 Notes Hobby hunting European Stormpetrel Nathan Cricks, Commensalism and incipient kleptoparasitism by Wood Pigeon on Eurasian Jay J. T. R. Sharrock, Berthelot's Pipit feeding on lizard Airam Rodriguez, Beneharo Rodriguez and Tinguaro Montelongo, Some observations on Wallcreeper nest material Mike Crewe, Mixed Great Tit/Blue Tit broods in nestboxes in south Worcestershire Peter Holmes
	446 Reviews Birds of Northern South America: an identification guide, Larks and Leverets: wildlife on Norfolk farmland, The Birds of Cardiff
	448 News and comment Adrian Pitches
	451 Recent reports Barry Nightingale and Eric Dempsey

The changing status of Balearic Shearwater in northwest European waters Russell B. Wynn and Pierre Yesou

Sightings data collated from the European Atlantic coastline reveal a recent change in the post-breeding distribution of the Balearic Shearwater Puffinus mauretanicus, and provide evidence for a progressive northwards shift in dispersal patterns. Numbers recorded in the traditional post-breeding quarters, centred on the French Biscay coast, have declined since the mid 1 990s and now show marked inter-annual variability. In contrast, numbers recorded from northwest European coastlines have increased since the mid 1 990s, the majority being seen along the coasts of northern France and southwest Britain, with smaller numbers north to southern Scandinavia. Although variability in observer effort may have contributed to the observed increase in northwest Europe, the spatial and temporal consistency of the data suggests that the trend is real. Large numbers of this Critically Endangered seabird are now spending part of the year in British and Irish waters; this paper highlights the need for future effort-based surveys across the species' non-breeding range, and will provide a baseline for conservation measures in northwest European coastal regions, where large concentrations now occur regularly.

Balearic Shearwater Puffinus mauretanicus, off Scilly, July 2005, Bryan Thomas

Identification of 'black-and-white' storm-petrels of the North Atlantic Robert L. Flood and Bryan Thomas

This review article consolidates identification criteria for the six species of , black-and-white' storm-petrel recorded or claimed in the North Atlantic: European Storm-petrel Hydrobates pelagicus,Wilson's Storm-petrel Oceanites oceanicus, leach's Storm-petrel Oceanodroma leucorhoa, Madeiran Storm-petrel O. castro, Black-bellied Storm-petrel Fregetta troPica and Whitebellied Storm-petrel F. grallaria. Established knowledge is updated with fresh insights and illustrated with instructive digital images.We have two aims: (a) to support County Recorders in Britain now responsible for evaluating Wilson's Storm-petrel submissions; and (b) to bring to a wider international audience current understanding about identification of North Atlantic 'blackand-white' storm-petrels. The article has two main sections: (a) a general discussion about identification of the storm-petrels under review; and (b) detailed species accounts, and information on how each species can be distinguished from the other five species (though white-bellied Fregetta storm-petrels remain problematic). A template that outlines our view of what constitutes a sound submission of a reportable 'black-and-white' storm-petrel is proposed. The main text is supported by ten appendices covering size illusion and exaggeration, factors of scale, angle of view, descriptive terminology for flight behaviour, chum and chumming, and wear, moult and bleaching. We focus on vessel-based observation since, realistically, this is the optimal means of getting to grips with storm-petrels in the field and is the main source of our experience. land-based observation rarely affords the views essential to apply the finer points of this presentation.

European Storm-petrel Hydrobates pelagicus off Scilly, July 2005 Bryan Thomas