Oology Unshelled John M

COMMENT BOOKS & ARTS

Some birds evolve signature egg colours and patterns to confuse nest parasites such as the cuckoo finch. Each column shows eggs from one host species.

ORNITHOLOGY Oology unshelled John M. Marzluff extols a rich history of ornithology’s debt to egg collecting.

im Birkhead has spent much of the fascinate Birkhead own eggs. This, however, is only part of the past four decades watching birds, and even as he laments this story of egg colour. Other species’ eggs are in particular mucking around guano- now illegal and inad- marked to camouflage them: the Japanese Tcovered ledges on which seabirds breed. His missible practice. He quail (Coturnix japonica), for example, lays insights have revolutionized ornithologists’ tracked down many heavily mottled eggs in nest sites with match- understanding of mate fidelity; his ability to old collections to learn ing patterns. Some eggs, such as that of the distil complex science for the general reader, more about the evolu- ostrich (Struthio camelus), are white to pro- for example in Bird Sense (Bloomsbury, tion of shape and col- tect the developing chick from the heat of the 2013), has revealed what it is like to be a bird. our. Through careful Sun. Others are brightly coloured, as with the Now, with an eye on past discoveries and per- evaluation of alterna- The Most Perfect American robin (Turdus migratorius), whose sistent puzzles, The Most Perfect Thing reveals tive hypotheses, he Thing: Inside (and blue eggs advertise the quality of the brood- AND CLAIRE SPOTTISWOODE ELEANOR CAVES what it is like to become a bird — from nas- dispels the common Outside) a Bird’s ing female. Still others may be lightly pig- cent ovum to shelled egg and beyond. explanation that the Egg mented to raise their internal temperatures Birkhead starts his story in the nineteenth pear shape of the guil- TIM BIRKHEAD or to increase light penetration, which can Bloomsbury: 2016. century, on English cliffs where eccen- lemot’s egg evolved speed up chick development. This mecha- tric collectors wait anxiously for daring mainly to keep it nism may be used to synchronize hatching “climmers” to fetch unusually shaped and from rolling off the nest precipice. Rather, within a clutch: the last eggs laid are often patterned eggs from the nests of common the shape probably provides legroom for the lightest in colour. Through the eye of this guillemots (Uria aalge). Especially prized the developing chick, enables the egg to tip careful evolutionary ecologist, and a series of was a sequence of eggs laid by the same above the faecal stew that often surrounds it, high-quality colour plates, we come to appre- bird throughout her life: each was identi- and increases surface area — improving heat ciate the beauty and functionality of eggs. cally marked with a design of splotches and transfer during incubation. Having considered the whole egg, Birkhead scribbles. The exten- With equal thoroughness, Birkhead shows next describes its making. He writes clearly, sive collections of NATURE.COM that the unusual markings — from light pep- with accuracy and wit, about the ovum’s early oologists, such as For more on science pering, squiggling and blotching to com- development in the bird’s ovary and its jour- George Lupton, who in culture see: pletely blackened ends or dark rings around ney through the oviduct. We learn about the amassed more than nature.com/ the midline — that entranced collectors microstructure of the shell — much like a 1,000 guillemot eggs, booksandarts enable guillemot parents to recognize their rigid sieve — and how pores and cuticle adapt

174 | NATURE | VOL 532 | 14 APRIL 2016 © 2016 Macmillan Publishers Limited. All rights reserved BOOKS & ARTS COMMENT the egg to local atmospheric conditions, as well as repelling water, hydrophilic microbes and contaminants that can diffuse in and Books in brief challenge the developing embryo. Foreign bodies that make it past the shell are dealt with The Great Departure: Mass Migration from Eastern Europe and the in the albumen, which Birkhead describes as Making of the Free World a “sophisticated biochemical firewall against Tara Zahra W. W. Norton (2016) microbes”. He then explains how the yolk As many as 58 million Europeans seeking “bread and freedom” provides fats and proteins manufactured in poured into the Americas from 1846 to 1940. Millions returned — the mother’s liver to the growing chick; it also worn down by the punishing, ill-paid labour driving the New World’s furnishes the chick with crucial antioxidants, booms. Historian Tara Zahra’s timely, myth-busting chronicle shows vitamins and hormones such as testosterone. how, early on, European states attempted to “scientifically” manage The embryo’s survival may be enhanced masses of people to serve their own and international goals. The by the odorous, oily secretions of the moth- impacts ranged all the way from the Holocaust to a shift in the er’s preen gland that grease the eggs’ shells concept of freedom, to the right to stay or leave. during laying and incubation. In some species, such as the hoopoe (Upupa epops), this oil mixes with the copious droppings in the 15 Million Degrees: A Journey to the Centre of the Sun nest to produce a notorious ‘filth’, which may Lucie Green Viking (2016) include beneficial bacteria that enhance Earth may be 150 million kilometres from the Sun, but few hatchability. Conservation biologists work- relationships are as intimate. Aside from the star’s centrality to life, ing to restore rare species may find that the our planet is embraced by the magnetic bubble of the heliosphere. lack of such bacteria helps to explain why Solar physicist Lucie Green’s engrossing primer clearly explicates many eggs are difficult to hatch without at the science and its star-studded history. That stretches from Galileo’s least a modicum of parental incubation. work on sunspots to astronomer Cecilia Payne-Gaposchkin’s 1925 Along the way, Birkhead introduces many discovery that helium is the most abundant element in the Sun — colourful characters little known to science. and physicist Sami Solanki’s 2004 finding that the past 70 years of Sequences of eggs collected from the 1970s grand-maximum solar activity may be a rare blip. to the early 2000s by John Colebrook-Rob- jent in Zambia were crucial to our understanding of the ‘arms race’ in egg coloration Show Me the Bone: Reconstructing Prehistoric Monsters in between nest parasites and their hosts. Birds Nineteenth-Century Britain and America such as cuckoo finches (Anomalospiza Gowan Dawson University of Chicago Press (2016) imberbis), for instance, sneak their eggs into A putative knack for mentally constructing a beast entire from the nests of others, but must continually a scattering of fossilized remains lent early palaeontologists a adjust the background colour and pattern to sorcerer-like glamour. As the field’s founder, Georges Cuvier, put it: fool the hosts — which in turn evolve unique “Give me the bone, and I will show you the animal.” Science historian markings to foil the parasite’s disguise. Lup- Gowan Dawson lucidly traces the afterlife of Cuvier’s incorrect “law ton’s guillemot-egg collection inspired and of correlation” in Victorian Britain and the United States. The idea informed current understanding of the seeped into science, irking biologist T. H. Huxley and, argues Dawson, adaptive value of egg shape. British physi- subtly influencing Charles Darwin’s thinking on natural variation. cian Allen Thomson speculated that the yolk is built up in layers. Birkhead’s ability to weave together history and science shows The Future of the Suburban City: Lessons from Sustaining Phoenix the human nature of research. Grady Gammage Jr Island (2016) He has a marvellous way with words, writ- The car, the shopping centre and the single-family home, reveals ing of monogamous albatrosses living like urban specialist Grady Gammage Jr, created the “suburban city” — “long-distance truck drivers — at home with sprawls clustered in the US southwest and associated with rampant their partner only occasionally and making development. In his study of their potential for sustainable transition, the most of it when they are”. And he tanta- Gammage focuses on Phoenix, Arizona — vast, traffic-ridden and lizes with unsolved mysteries. Why, for exam- caught between aridity and a per capita water consumption more ple, does the egg of a chicken travel through than twice that of New York. He argues that its historic reliance on the hen pointed end first until the very last renewable surface water rather than groundwater, and openness to minute, when it turns through 180° on the low-carbon light transport, point to a potential for future resilience. horizontal plane to be laid blunt end first? Birkhead’s historical acumen and sharp pen had me seeing eggs in a new light. He Switched On: A Memoir of Brain Change and Emotional Awakening has convinced me that they are splendid, if John Elder Robison Spiegel & Grau (2016) not indeed most perfect. ■ In 2007, John Elder Robison published Look Me in the Eye (Crown), a raw memoir about growing up with Asperger’s syndrome. The John M. Marzluff is the James W. Ridgeway following year, cognitive neurologist Alvaro Pascual-Leone invited him Professor of Wildlife Science in the School to participate in a study involving transcranial magnetic stimulation of Environmental and Forest Sciences at the (TMS). Here, Robison chronicles the “powerful mojo” that ensued as University of Washington, Seattle. His latest his emotions, empathy and perceptions deepened, colouring work and book is Welcome to Subirdia. intimate relationships unexpectedly, even after the TMS effects faded. e-mail: [email protected] The science and ethical quandaries are deftly interlaced. Barbara Kiser