Working for birds in Africa

Petrels Night and Day

Fri, 12/21/2012 - 11:43 -- abc_admin
Magnus Robb, Killian Mullarney & The Sound Approach, 2008. Poole: The Sound Approach. 300 pp, many colour photographs, colour maps and sonograms, and two free CDs. Hardback. ISBN 987–90–810933–2-3. UK£ 34.95.
pages 114-115

This large-format, full-colour book represents the exciting second output of The Sound Approach team. It is a guide, in photographs, beautiful colour paintings (by Killian Mullarney), many sonograms and two CDs, to 22 taxa of Procellariidae and Hydrobatidae that breed in the Western Palearctic (though not made explicit, the region's definition is that of BWP). One of these, Swinhoe's Storm Petrel Oceanodroma monorhis, has only recently been discovered in the north-east Atlantic and its precise status still requires elucidation. In addition, three other non- breeding visitors are illustrated in colour plates, Great Shearwater Puffinus gravis, Sooty Shearwater P. griseus and Wilson's Storm Petrel Oceanites oceanicus, and a vagrant (a Black-capped Petrel Pterodroma hasitata encountered during one of the author's research trips to the Azores) is depicted only photographically. Of the 22, one (Monteiro's Storm Petrel) has but recently been named (Bolton et al. 2008) and another, Cape Verde Storm Petrel Oceanodroma (castro) jabejabe, has lain in synonymy for many years. A mere handful, Balearic Shearwater Puffinus mauretanicus, Northern Fulmar Fulmarus glacialis and Mediterranean Storm Petrel Hydrobates (pelagicus) melitensis do not breed in the ABC region, and probably all of these have been recorded as non-breeders.

Unsurprisingly, the taxonomy employed in this book, whereby all 22 taxa are treated as species, effectively mirrors that in the most recent Dutch Birding list of Western Palearctic birds, which was also published in 2008. Thus Fea's Pterodroma feae and Desertas Petrels P. deserta are treated specifically, as are all three taxa within the old Cory's Shearwater Calonectris diomedea, two species of 'Little Shearwater' are recognised (Barolo's Puffinus baroli and Boyd's P. boydi), and Band-rumped Storm Petrel Oceanodroma castro has become four species, and that doesn't even fully address the problems posed by other populations elsewhere in the world! If that's not enough, it seems likely that other once-familiar species might be 'reorganised' too, as I discovered whilst throwing oil, rotting fish and popcorn over the side of a boat off southern Baja California two years ago, to attract Leach's Storm Petrels Oceanodroma leucorhoa within range of Hadoram Shirihai's lens (you can gain some insight into what's going on by turning to p. 226 of this book). Before twitchers get too carried away, however, it must be noted that positively identifying this 'new' biodiversity at sea seems to involve detailed evaluation of moult state or is impossible.

Each 'species' is subject to its own section and all are illustrated by stunning colour photographs, from an evocative image of a Leach's Storm Petrel 'riding the storm' in an autumnal north-west England (p. 212), to stunning portraits of Mediterranean Storm Petrels 'crawling' to their burrows in the 'brain-like' rock surface of a Sicilian sea-cave (p. 204). Reminders of how far seabird photography at sea has progressed since Harrison published his guides are innumerable. Furthermore, we never lose sight of the birds' dramatic environments, from the wonderful photograph on p. 14 of the breeding grounds of Zino's Petrel Pterodroma madeira, they are almost as closely in focus as the birds themselves.

The species texts range quite widely, covering historical issues and conservation to the inevitable latest modern genetic 'thinking', via the author and his colleagues' obviously life-affirming experiences in search of petrels, literally 'night and day'. They focus on the beautiful recordings presented on the accompanying CDs (best listened to, as the author often reminds us, using headphones), describing them (and frequently the efforts made in their acquisition) and what they tell us about sexing petrels by voice, geographical variation in vocalisations, and taxonomy. Many of the photographs were taken simultaneously with the recordings. Use of vocalisations to determine species limits in Procellariiformes is not new, but does not possess a long history. For instance, Bretagnolle (1995) split Northern and Southern Hemisphere populations of 'soft- plumaged' petrels on the basis of vocal differences, but his analysis of those northern populations is postulated to be at fault in this book, and certainly division of north-east Atlantic birds into two species, rather than one, had already been widely accepted, contra Bretagnolle's treatment. Now, as earlier speculated by Ratcliffe et al. (2000), vocalisations (this book) and molecules (cf. van den Berg & Haas 2008) provide support to recognise a third species in this region. What I missed in the present work was more than passing reference to studies such as those by James (1985) and Ratcliffe et al. (1998), which have found evidence for geographical (dialectical) variation in vocalisations of Manx Shearwater Puffinus puffinus and British Storm Petrel Hydrobates pelagicus, which lead to questions as to why variation in vocalisations described here should be regarded differently (i.e. to support specific status). Nor do we learn why playback studies cited to support taxonomic treatments adopted here should be regarded as more robust than, for instance, those of Mitchell et al. (2004), which found that British Storm Petrel can respond to playback of Leach's Storm Petrels, or Carruthers et al. (1989), wherein it was revealed that Swinhoe's Storm Petrels might dive into mist-nets in response to broadcasting of British Storm Petrel vocalisations. Such results suggest that we do indeed need to treat playback trials cautiously, as effectively recommended by Helbig et al. (2002), notwithstanding the discovery by Bretagnolle (1996) that vocalisations appear to be inherited, rather than learned, in at least some tubenoses. Evidence that in others learning might play a part is debated (James 1985, Slater 1991). As such, Robb's fascinating research tends to throw up as many new questions as it deals out answers, with which observation I'm sure he would be in general agreement.

Discussions of sonographic minutiae are inevitably hard to convey in the same style as the rest of the book's prose, which is refreshingly readable (rarely can I claim to have truly read a bird book sent for review, but this was one exception that proved the rule). It is also mercifully free of typographical or other errors, though the author does make that age-old slip of thinking that birds (and ships) pass through the Straits of Gibraltar, rather than the Strait.

Despite quite some reservations as to whether the 'expansive' taxonomy adopted by the guide represents a genuine step forward in our understanding of petrel systematics, I am nonetheless left full of praise for this multi-media extravaganza. It merits attention from all those who love Western Palearctic birds, seabirds in general, or the north-east Atlantic Islands in particular. In recalling an encounter with a flock of Great Shearwaters off western Ireland recounted in this book's pages, Anthony McGeehan concluded 'A lesson confirming humankind's place in evolution: above rodents, below seabirds'. He might just as well have been describing this book.

Guy M. Kirwan
References: 
van den Berg, A. B. & Haas, M. 2008. WP reports. Dutch Birding 30: 260–270.
Bolton, M., Smith, A. L., Gómez- Díaz, E., Friesen, V. L., Medeiros, R., Bried, J., Roscales, J. L. & Furness, R. W. 2008. Monteiro's Storm-petrel Oceanodroma monteiroi: a new species from the Azores. Ibis 150: 717–727.
Bretagnolle, V. 1995. Systematics of the Soft-plumaged Petrel Pterodroma mollis (Procellariidae): new insight from the study of vocalizations. Ibis 137: 207–218.
Bretagnolle, V. 1996. Acoustic communication in a group of non-passerine birds, the petrels. In Kroodsma, D. E. & Miller, E. H. (eds.) Ecology and Evolution of Acoustic Communication in Birds. Ithaca, NY: Cornell University Press.
Carruthers, M. P., Cubitt, M. G. & Hall, H. 1989. The dark-rumped petrels in Tyne & Wear. Birding World 2: 288–289.
Helbig, A. J., Knox, A. G., Parkin, D. T., Sangster, G. & Collinson, M. 2002. Guidelines for assigning species rank. Ibis 144: 518–525.
James, P. C. 1985. Geographical and temporal variation in the calls of the Manx Shearwater Puffinus puffinus and British Storm-petrel Hydrobates pelagicus. J. Zool. Soc. Lond. 207: 331–344.
Mitchell, P. I., Newton, S. F., Ratcliffe, N. & Dunn, T. E. (2004) Seabird Populations of Britain and Ireland. London, UK: T. & A. D. Poyser.
Ratcliffe, N., Vaughan, D., Whyte, C. & Shepherd, M. 1998. Development of census methods for Storm Petrels Hydrobates pelagicus. Bird Study 45: 302–312.
Ratcliffe, N., Zino, F. J., Oliveira, P., Vasconcelos, A., Hazevoet, C. J., Costa Neves, H., Monteiro, L. R.& Zino, E. A. 2000. The status and distribution of Fea's Petrel Pterodroma feae in the Cape Verde Islands. Atlantic Seabirds 2: 73–86.
Slater, P. J. B. 1991. Learned song variations in British Storm- petrels? Wilson Bull. 103: 515–517.

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