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22 January 2020 Book Reviews
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For books on feathers there is no continent like Europe, more specifically: western Europe, or, to be honest, mostly Germany. All these books, no matter how useful in themselves, have deficits that leave something to be desired: incomplete feather series, only rectrices, not in colour, limited number of species, in German, and so on. Although some feather books fleetingly mention the use of feathers for ecological studies, notably in the realm of moult, the majority focus on identification of feathers sec. Marian Cieślak uses a different approach for owl feathers. Indeed, only 28% of the pages are used for the standard treatment of fourteen owl species (except Asio capensis all of them European species): photographs of a selection of flight feathers, where possible separately for sex and age (no information on sexing in Tyto alba, but see de Jong & van den Burg 2012 for guidelines), accompanied by text covering feather size, feather shape, colouration, individual variation and moult. Surprisingly, no scale is used in the photographs (although feather lengths are given in appendices), nor are the selected feathers numbered; the latter is partly remedied by providing silhouettes of primaries (not secondaries or rectrices) separately. Photographs of full-spread wings are used to show moult from juvenile to adult plumage.

Other chapters deal with a potpourri of subjects, i.e. feather types, wing shapes, wing-loading, colouration, moult strategies, wing-loading, diastataxis, sexual dimorphism, abnormalities and measurements. Wherever possible, feathers and plumages are linked to biological and ecological traits, as in hearing, vision and flight. For example, sexual dimorphism in plumages of owls as perceived by the human eye may be at variance with the owl's perception (using UV-light). Although true in itself, and certainly important to be aware of, this remark is accompanied by quoting the Finnish study about Eurasian Kestrels apparently using UV-light to detect rodents via their urine in runways (Viitala et al. 1995), a study that has been falsified by later research (Lind et al. 2013). Moult strategies are put in the perspectives of age and breeding performance. Several owl species are at variance with general models explaining moult strategy by bird size, which may reflect their dependence on a highly variable food supply (vole peaks and lows impact brood size and hence energetic costs of feeding nestlings).

The book should be read as a work in progress. The accumulation of information on a wide range of topics, sometimes without direct bearing on the subject, reveals an owl lover par excellence. The organization of the text is a bit of a tombola, also visible in the appendices where a multitude of subjects are reviewed and quantified: feather length (minimum, maximum, average, sample size) for primaries and secondaries, as well as derived data (wing roundness), an exposé of the difficulties of finding feathers of Glaucidium passerinum in the field, anatomical and morphological information on heads and skulls, and how to measure feathers. The lack of an index is acutely felt. Owl aficionados will find much of interest though, including avenues for future research, whereas the general reader and feather enthusiast are served with a plenitude of information illustrated with superb photographs (feathers are by standard portrayed against a black background, which works wonders). The reproduction on glossy paper is excellent, and this alone will make the book a treasure for those of us interested in owls and feathers. This English translation is a slightly amended version of the Polish edition (2014). Unfortunately, the author passed away before its publication, although he was able to participate in the final editing. His extensive feather collection is deposited in the Upper Silesian Museum in Bytom, Poland.

References

1.

de Jong J. & van den Burg A. 2012. A new method to sex Barn Owls Tyto alba. Ardea 100: 95–97. Google Scholar

2.

Lind O., Mitkus M., Olsson P. & Kelber A. 2013. Ultraviolet sensitivity and colour vision in raptor foraging. J. Exp. Biol. 216: 1819–1826. Google Scholar

3.

Viitala J., Korpimäki E., Palokangas P. & Koivula M. 1995. Attraction of kestrels to vole scent marks visible in ultraviolet light. Nature 373: 425–427. Google Scholar

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Since atlassing has become fashionable in western Europe, i.e. in the 1970s when societies had recovered from the ravages of World War II and leisure/money soared, birdwatchers have enthusiastically produced one breeding bird atlas after the other. For Switzerland/Lichtenstein, the present atlas is already the third, covering 2013–2016 (previous ones were based on fieldwork in 1972–1976 and 1993–1996, with a precursor for 1950–1959). Again, a massive tome, which – when put on the same shelf as the other atlases, necessitates a specially strengthened bookcase to carry the weight. Where does it end?

Switzerland is so small (41,285 km2) that distributional mapping was possible at the level of 10×10 km-squares (n = 467). Density maps were based on 2318 1×1 km-squares where breeding birds had been quantitatively censused using standardized methods; these squares were well-distributed across the country except for the highest altitudes (>2500 m), with 3–5 squares per 10×10 km-square. The Swiss have chosen for a relatively simple lay-out: a density map, a map showing relative change compared to the previous atlas for 1993–1996, a set of small maps to illustrate presence in four periods since 1950, and graphs showing altitudinal distribution and indexed trends (for 1990–2016). Texts are relatively short, often contain real information (i.e. densities or numbers) and try to give some perspective to Swiss trends by incorporating information from neighbouring countries and from the literature. Occasional breeding birds receive attention in an appendix, just as fourteen exotics (Black Swan, geese, ducks, parrots). Anyone interested in the fortitudes of Swiss breeding birds can find useful information, backed by a large body of literature.

Nobody reads an atlas from cover to cover. Despite efforts to condense the information in introductory chapters, bigger themes usually lose their coherence when splintered across the species accounts. Not so in this atlas. In fact, the outstanding feature of the Swiss atlas is the introduction of thematic interludes scattered throughout the species texts, one- or two-page intermezzi elaborating more general phenomena related to a suite of species. The species texts refer to these pages when relevant (and vice versa). Cormorant Phalacrocorax carbo, for example, has four such points of interest, viz. hunting and persecution, Switzerland as a paradise for fish-eating birds, newcomers among breeding birds and a review of lost and new breeding birds since 1900. It is a pity that the table of contents does not specify the 35 intermezzi. On the other hand, an element of surprise in an atlas is to be applauded. Another surprise was the species text for ornithologists attributing to the fieldwork, at the end of the book. Observation intensity was highest below 600 m, the number of bird watchers increased from 919 for the previous atlas in 1993–1196 to 3517 in 2013–2016 (which makes you wonder about the impact on maps and trends as compared to previous efforts) and the use of smartphones boosted the amount of data collected. The new era of bird watchers!

Rob G. Bijlsma "Book Reviews," Ardea 107(3), 345-346, (22 January 2020). https://doi.org/10.5253/arde.v107i3.a14
Published: 22 January 2020
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