Wednesday, July 16, 2008

Petrels Night and Day: A Sound Approach

Every once in a while there comes a book that breaks the mold, radically changing our expectations of what a good bird book should be. Petrels night and day: A Sound Approach guide is one such book.

PNAD as I shall refer to it henceforth, is part audio-guide, part field-guide, part natural history and part travelogue. In 300-pages, it covers the twenty or so tubenoses (petrels, storm-petrels, fulmars and shearwaters) that nest in the Western Palearctic [WP] faunal region, ostensibly the western North Atlantic and Mediterranean. I hesitate to quote an exact number of species because the authors take an innovative, but well-considered, approach to the taxonomy. Some of the proposed splits rest on firmer foundations than others, but more on this anon.

Written primarily by Magnus Robb with painted plates from his collaborator Killian Mullarney, the book is truly a team effort with further seminal contributions from Arnoud van den Berg and Mark Constantine, co-founders with Robb of a new publishing endeavor and natural sound archive known as The Sound Approach, Réne Pop and several others. A supporting cast of seabird experts and conservationists provide additional input, assistance in the field and the freedom to quote their unpublished findings.

As a bird guide, PNAD defies convention in almost every aspect starting with its 20 x 29 cm landscape format that is more typical of books on fine-art, architecture and such like. The production quality is very high; the book feels wonderfully solid in the hand, with beautiful color reproduction on the many photographs, maps, diagrams and painted plates. The narrative thread follows a quest to explore and understand the tubenoses of the WP region through their vocalizations and other field observations. A whopping 127 separate audio recordings are provided on two compact discs (CDs), the majority collected by Magnus Robb, a musician and sound engineer by training. The recordings are meant to be listened to as the book is read and are integral to the text. Carefully annotated sonagrams are included and help the uninitiated to pick apart the decidedly unfamiliar noises. I'm not fluent in these depictions of complex sounds and to my naïve eyes, most could as easily depict the Loch Ness monster hovering in the watery depths as the chatters and purrs of a storm-petrel in its rocky crevice. I suppose I can follow the more obvious trends but I’m quite blind to the meaning of the finer structure. Robb’s explanations of the complex traces are wonderfully clear and revealing. Color is used to good effect, for example when multiple birds (males and females) are calling to one-another. Like most birders, I can usually hear the similarities and differences in natural sounds but struggle to remember them, let alone transcribe them. Working through a few of the many recordings, gave me a whole new appreciation for the strange and haunting noises associated with petrel or shearwater colonies.

In spite of the title, the book is much, much more than a guide to vocalizations. It is in truth a sweeping natural history guide covering many aspects of tubenose biology, ornithological history and the pure pleasures of experiencing amazing birds in the wild. Through wonderfully evocative photographs and descriptions, we are transported to some extraordinary places. In the Egadi Islands off Sicily, we follow Arnoud van den Berg and Réne Pop as they swim from a small boat into dank caves used by Mediterranean Storm Petrels (Hydrobates melitensis), following the waft of ‘petrel scent’ to find the birds roosting on slipperly ledges in the semi-darkness. Wow! That sounds like fun. Elsewhere, we are introduced several times to the arid hills and coastlines of the Cape Verde Islands, a fascinating archipelago located several hundred miles off the coast of West Africa, as well as to the greener slopes of the even more remote Azores in the mid-Atlantic.

Killian Mullarney’s eighteen painted plates occupy a full page each, a generous format that does justice to his exceptional artwork. All too often publishers fail to provide sufficient space to showcase outstanding artwork or photographs – not so here. Throughout the plates, there is a strong emphasis on field identification with vignettes showing birds alighted on the water, at their borrows and in flight, often in company of species as they would be in the field. Some of the shearwaters are shown under different lighting conditions to emphasize the effect that direct sunshine or heavily overcast conditions can have of plumage features. Manx Shearwaters (Puffinus puffinus) for instance, can look quite plain faced in very direct sunlight, suggesting one of the Little Shearwater complex. Well-chosen photographs scattered through the text reinforce many of the points illustrated in the plates. The under-appreciated similarities between dark Balearic Shearwater (Puffinus mauretanicus) and Sooty Shearwater (Puffinus griseus) is clearly shown in the plates on pages 138 and 157. The potential for confusion with Short-tailed Shearwater (Puffinus tenuirostris), a Pacific species that has made it to the Gulf of Mexico and perhaps beyond, might also be borne in mind.

While most of the species will be quite familiar to birders on either side of the Atlantic, there are number of subdivisions (splits) that guaranteed to spark healthy discussion. It is no surprise that ‘Little Shearwater’ of old is duly separated into two taxa; Barolo’s Shearwater (Puffinis baroli) nesting across the European sector of Macaronesia and Boyd’s Shearwater (Puffinis boydi) of the Cape Verde Islands. These are really quite different beasts and the dual treatment will be helpful to many birders struggling to keep up with the explosion of new knowledge on the small black-&-white shearwaters. Unfortunately, Audubon’s Shearwater (Puffinis Iherminieri), an abundant breeder in the Caribbean and routine dispersant northwards along the Gulf Stream as far as New England, gets only the briefest of mentions; understandable I suppose, but a fuller treatment would have rounded out the comparisons, increased the appeal of the book to the North American audience and might perhaps lead to sightings in WP waters.

It is gratifying to see that Swinhoe’s Storm Petrel (Oceanodroma monorhis), a recent but well-documented addition to both the WP and North American avifaunas, gets full treatment, including an opportune account of how the first Atlantic bird was discovered through its unfamiliar vocalizations on the Portuguese island of Selvagem Grande in June 1983 by Paul James and Hugh Robertson. This, as it turns out, was not a freak occurrence but one of several birds to be captured over the years on this one island and Swinhoe’s Storm-Petrels have now been found at many other locations in the Eastern Atlantic and Mediterranean, with at-sea sightings in the Western Atlantic.

From the pattern of recoveries, there seems a strong likelihood that Swinhoe's are attempting to nest, at least occasionally, on Selvagem Grande, if not elsewhere. By coincidence, during the final stages of the book's preparation, researcher Rafael Matias recaptured the original 1983 bird on 21 August 2007. This celebrated male Swinhoe's must be at least 25 years old and sound recordings and photographs of the resilient ol’ timer are included. Venturing farther afield, I enjoyed the account of visits by Messrs van den Berg and Pop to a sizeable Swinhoe's colony on Chilbaldo, an islet off the coast of South Korea. Robb makes a good case for the need to search large British Storm Petrel colonies, which he argues may be better for Swinhoe's than colonies of large species such as Leach's Storm Petrel (Oceanodroma leucorhoa) or Band-rump types (Oceanodroma sp.).

While detailed coverage is focused on breeding species, the most abundant migrants into the region, Great Shearwater (Puffinis gravis), Sooty Shearwater (Puffinis griseus) and Wilson’s Storm Petrel (Oceanites oceanicus) are illustrated and discussed at length. This is not so for three deep-water gadfly petrels that have occurred in the WP, Black-capped Petrel (Pterodroma hasitata), Bermuda Petrel (Pterodroma cahow) and Trindade Petrel (Pterodroma arminjoniana) which get only the briefest of mentions. This is a pity because of their similarities to other species and strong likelihood of reoccurring in the WP and there are even hopes that Bermuda Petrel may one day nest on the Azores. Perhaps a future edition could incorporate a painting showing the thrilling trio? If Killian feels he lacks sufficient field experience to do them justice, but perhaps the publishers (aka his pals) will summon up the dough to send him to North Carolina for a month or two or better still, to the Atlantic and Caribbean breeding grounds of each of these dynamite gadfly petrels.

Distinctions are drawn between Fea’s Petrel (Pterodroma feae) of the Cape Verde Islands and Desertas Petrel (Pterodroma deserta) of Bugio in the Desertas Group and possibly the Azores to the northwest. As Robb points out, “almost everything we known about the breeding biology of ‘Fea’s Petrel’ actually refers to Desertas Petrel”. The two look very similar but nest in different seasons and also differ in several measurements. There may be subtle differences in plumage coloration as well but like the morphometrics, this will be extremely difficult to apply at sea due to the vagaries of lighting and lack of direct comparison. Currently it is only the appreciably deeper bill of Desertas Petrel (average 12.9 mm compared to 11.9 mm for Fea’s), discernable in good photographs, that inspires hope for pelagic birders. Zino’s Petrel has a shallower and shorter bill and is likely to seem much stubbier (peg-like) than either Fea’s or Desertas. Hopefully, these issues will be resolved soon because a number of experts have made dedicated chumming trips off Madiera this past season and photographed candidate birds. The vocalizations of the three are distinctive and to Robb’s ear there are interesting similarities between Desertas and Bermuda Petrel.

The subdivision of Band-rumped Storm Petrel will spark the most vigorous debate. For more than a decade, scientists and other ‘seabird cognescenti’ have been ruminating over the taxonomy of the pantropical Madeiran/Band-rumped storm petrels and a significant body of genetic and ecological data to support the splits has been accrued. It has been argued that there are upwards of eight distinct populations spread across the Atlantic and Pacific basins worthy of full species status. In PNAD, Band-rumps are split into four species: Grant’s Storm Petrel (no scientific name assigned yet), Monteiro’s Storm Petrel (ditto), Madeiran Storm Petrel (Oceanodroma castro) and Cape Verde Storm Petrel (Oceanodroma jabejabe). Grant’s is a cool season (August-March) breeder of the Azores, Berlengas, Canary Islands, Madeiran archipelago and Selvagens. The name was new to me and was apparently proposed by Steve Howell to honor the late Peter Grant in lieu of a new species of gull. I believe Atlantic Storm Petrel has also been floated. Monteiro’s refers to the hot season (March-September) breeder found on the Azores and appropriately honors the late Luis Monteiro, a seabird biologist and conservationist from the University of Azores. Mark Bolton (A Rocha Field Study Centre, Portugal) and colleagues have submitted a formal scientific description of Monteiro’s Storm Petrel but I don’t know if it has been accepted for publication yet.

Reasoned arguments are made for the occurrence of several of these 'band-rumps' in North American waters during the non-breeding season and this is supported by photos and descriptions of birds taken in US waters that exhibit noticeable plumage and structural differences. Many of the birds studied off North Carolina in the summer (May-August) could be Grant’s but Cape Verde Storm Petrel, a partial cool-season breeder needs to be considered. Obviously there is much work to be done, not only from the waters around the breeding sites but also from the Gulf Stream off the US and in the Gulf of Mexico. Specimens of birds driven inland by tropical storms may be of value in piecing the story together. The cryptic complexity of the Band-rumps will resonate with pelagic veterans, many of whom have struggled to understand differences in jizz that are not easily attributable to molt. The realization that more than one species might be present is exciting and will galvanize future offshore trips.

At this point in the review, I can imagine overworked members of regional or national checklist committees reaching for the aspirin or whiskey bottle. Tempers have flared in the past over the treatment of extralimital sightings of Fea’s Petrels because of the perceived difficulty in ruling out the much rarer Zino’s Petrel. Clearly, the arrival of Desertas Petrel on this tempestuous scene, which is probably even harder to distinguish from Fea’s than Zino’s, will churn the waters further. Identifying the ‘new’ storm petrels will be equally challenging in the field. That said, some of them are decidedly rare and from a conservation standpoint, discovery of their non-breeding ranges through field observations is of paramount importance. Do any occur, I wonder, in the oil and gas fields of the Gulf of Mexico? I believe that Desertas Petrel, Mediterranean Storm Petrel and Cape Verde Storm Petrel have been elevated to full species status by the Dutch DBA/CSNA, but I am not aware of other authorities that have endorsed (or even debated) the splits.

Seabirds very often nest in dramatic and inspiring places, and through the pages of PNAD we are escorted to many remarkable locations around the eastern Atlantic and Mediterranean Sea. In the opening chapter, we climb up into the jagged 2,000 m (6,562 ft) peaks of Madiera, rocky pinnacles that literally rise above the clouds. Among the crags and rocky slopes surrounding the very highest point, Pico de Areeiro (32.7354°, -16.9289°), some 65-80 pairs of Zino’s Petrels (Pterodroma madeira) – perhaps the entire world population - make their nests. A stunning image of this unworldly and seemingly inhospitable landscape dominates page 14. Zino's Petrels visit on most nights from late March to late August and in spite of the remoteness, local guides are available to take visitors to listen to petrels calling in the darkness. A permit is required (make sure your guide has one) and needless to say, any use of tapes or spotlights is totally inappropriate.

Further on, we are treated to the sensory spectacle of 10,000 pairs of British Storm Petrels (Hydrobates melitensis) nesting alongside the ancient stone stairway of Skellig Michael, off County Kerry, Ireland (51.7706°, -10.5389°) and to the expansive fields of White-faced Storm Petrel (Pelagodroma marina) burrows on Selvagem Pequena (30°, -16°). With such a mouth watering list of places to visit the front cover ought to be stamped with a prominent warning label along the lines of, “Caution! Readers may experience feelings of intense wanderlust. If this occurs, drink plenty of fluids and consult your doctor/travel agent for further advice”. But this of course is the point, get out there and explore some of Europe's most remote places guided by the musky scent and surreal calls of nesting shearwaters and petrels.

A recent seabird book that draws fair comparison to PNAD is Hadoram Shirihai’s The Complete Guide to Antarctic Wildlife, which combined conventional field guide material (standardized species accounts, plates, range maps and so on) with a superb collection of photographs illustrating the environment as well as the birds and other animals. As with PNAD, Shirihai’s book is further enriched with an abundance of geographical and historical material that most readers find equally fascinating. The writing style of PNAD is more accessible than a typical academic text but is still rich in scholarship. Factual information is backed up by citations that link back to more than 200 references, the majority from the primary scientific literature. Hopefully many readers will be inspired to visit these additional writings as well as travel to see the birds and locations with their own eyes. The final chapter on Swinhoe's Storm Petrel sets out some innovative ideas about the inshore movements of storm-petrels during the hours of darkness and the ecological relationships between different species, offering a call to arms as it were to discover the migration route from the Indian Ocean and perhaps prove that this asiatic petrel is actually reproducing in the Atlantic.

Executive Summary: This remarkable book rolls the notions of a field guide, natural history survey and audio guide into a single volume and enthusiasts of every experience level will find much of value. Those planning monographs of other bird families (or faunal regions) may consider a similar multifaceted approach.

Species Covered: Zino’s Petrel, Fea’s Petrel, Desertas Petrel, Bulwer’s Petrel, Cory’s Shearwater, Scopoli’s Shearwater, Cape Verde Shearwater, Great Shearwater, Barolo's Shearwater, Boyd’s Shearwater, Manx Shearwater, Balearic Shearwater, Yelkouan Shearwater, Northern Fulmar, White-faced Storm Petrel, European Storm Petrel, Mediterranean Storm Petrel, Leach’s Storm Petrel, Grant's Storm Petrel, Monteiro’s Storm Petrel, Madeiran Storm Petrel, Cape Verde Storm Petrel and Swinhoe’s Storm Petrel.

Title: Petrels Night and Day: A Sound Approach Guide.
Authors: Magnus Robb and the Sound Approach
Publisher: The Sound Approach
300 pages, 18 painted plates, numerous color photographs, figs and maps.
2 CDs, 127 recordings.
ISBN-13: 9789081093323
Retail Price: £34.95 (UK)
Also available from the Natural History Bookstore(NHBS).

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