BOOK REVIEWS 959

Sterna forsteri) ; and black skimmer ( Rynchops niger) and by lesser nighthawks (Chordeiles aeutipennis), to miti- gate thermal and humidity stresses associated with nesting near the Salton Sea (southwestern California), where harsh Sonoran Desert conditions prevail. Some species were also studied in non-desert coastal sites, though grossly disproportionate amounts of attention are paid to the different species under study. It is difficult to under- stand why the gull-billed terns are included, as they are barely mentioned in the monograph, and skimmers are given little attention.

The research revealed many interesting and intricate interrelationships between the birds' thermoregulatory maintenance and incubation behaviours (pteryloerection; orientation to the sun; panting; gular fluttering; sitting on eggs tightly or loosely, or shading eggs; belly-soaking, and wetting eggs or chicks). The problem frequently faced by many field researchers interested in comparative study comes to the fore in this work: i.e. whether to take a broad view by incorporating many study species, or to focus on fewer species and delve more thoroughly into different levels of the hypotheses under investigation. One tactic trades off with the other, and both are important. In the present instance, however, a narrower, more in- tensive approach would have enhanced some data presentations and resulted in a more balanced production. Many of the most interesting findings are based on very small sample sizes and seem at times to be overgeneralized within and across species.

This criticism must be tempered by the realization that the logistics of the circumstances at hand no doubt shaped the research plan to some degree and that many fruitful and het~ristic results are offered. Of those species studied (killdeer, stilts, avocets, Forster's terns, skimmers), none showed any evidence of avoiding intense summer heat by nesting significantly earlier or later in the season than conspecifics in more temperate locations. The temperature of eggs directly exposed to solar radiation quickly reached lethal levels, and prevention of overheating was the funda- mental task of incubating adults. Water losses from eggs during incubation, which essentially accounts for lost egg mass, ranged from 9 ~ (Forster's terns) to 18 ~ (stilts) of initial egg mass, and averaged 1 3 ~ for six species. Ambient vapour pressures recorded on shaded ground within 1 m of nests were usually double those reported at nearby weather stations where data were collected 1.3 m above ground, illustrating the importance of collecting microclimatic data as close to the animal as possible. The potential water-carrying effects of belly-soaking, a behaviour shown by all the Charadriiformes studied, was neatly quantified by wetting belly feathers taken from specimens and comparing dry and wet feather -weights. Stilts, for instance, were estimated to transport up to 3 g of water to the nest during the course of a day. Bringing salt water to the nest poses other potential problems of increasing nest humidity and coating eggs with mud and salt. The oxygen consumption rates of stilt embryos in mud- and salt-covered and clean eggs were almost identical, and in the laboratory, chicks hatched success- fully from soiled eggs. Cbaradriiformes panted to dissi- pate heat by evaporative cooling, but did not gular-flutter, a behaviour pattern exhibited by nighthawks. Pterylo- erection, which reduces the heat reaching the skin, of dark dorsal feathers was exhibited by all species under heat stress. Stilts always panted prior to dorsal pterylo- erection, suggesting that panting is stimulated by lower rises in temperature than is feather raising. Belly-soaking occurred after intense dorsal pteryloerection.

Different species dealt with incubation routines in different ways. All Charadriiform parents shared incu- bation, whereas female nighthawks (the only species that gular-fiuttered) sat throughout the day. Terns and shore- birds exchanged places at the nest more often during the hottest part of the day and made frequent trips to water to belly-soak and drink. Killdeer, plovers and F0rster's terns shaded their eggs at moderate to high ambient temperatures, but once ambient shade temperatures ex- ceeded the egg incubation temperature, tight sitting followed. Stilts and avocets sat tightly and did not shade their eggs.

Like Drent (1970. Behav. Suppl., 17, 1-132), Grant concludes that egg temperature represents an extension of parental core body temperature, and is maintained within well-defined limits by the behavioural and physiological mechanisms that regulate the core temperature of an incu- bating adult. Egg care behaviour seems more closely tied to core temperature than to that of the eggs or to nest humidity. The monograph ends with the interesting speculation that belly-soaking, which appears to be re- stricted to Charadriiformes, is derived from 'displacement brooding distraction displays', which may also be re- stricted to t~fis avian group.

Overall the monograph is stimulating and informative and raises many interesting research questions. Etho- logists interested in the mechanisms and adaptive signifi- cance of parental care patterns will enjoy this monograph and find much food for thought in it.

W. A. MONTEVECCH[ Newfoundland Institute for CoM Ocean Science and Department of Psychology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada AOA 3KO.

Brain and Intelligence in Vertebrates. By EUAN M. MACPHAIL. Oxford: Oxford University Press (1982). Pp. viii +423. Price s hardback, s paperback.

The question raised in the first chapter of this book is quite clear: are there contrasts in the behavioural capaci- ties of various vertebrate groups which might reflect qualitative or quantitative differences in intellectual mechanism? Before reviewing the evidence, Euan Macphail first discusses the means of assessing intelligence in animals, though he side-steps any definition with a neat recourse to precedent. To reveal on page 3 that it is un- necessary to 'provide the definition for a word whose meaning is already well known' struck me as counter- productive so early in a book with 'intelligence' in its title. Nor did the opening to Chapter 2 - The physio- logical analysis of intelligence - - allay my fears. It begins 'Behaviour is a consequence of brain activity: it therefore makes good sense to look to differences between brains for an explanation of differences in behaviour'. Evoking the concept of causality surely misses at least one half of the point! Behaviour is an expression of the continual trans- actions of an organism within its environment and to look to comparative anatomy appears at once an archaic and arid approach.

The bulk of the book comprises five chapters, one for each of the major vertebrate groups. In each, performance on a variety of learning tasks is reviewed and assessed. Each chapter provides an exhaustive account of the literature. Comparisons of performance are made pri- marily between species of the same class or between that class and mammals. The conclusion that the author reaches is that there are no compelling grounds for sup-

960 A N I M A L B E H A V I O U R , 3 1 , 3

posing any qualitative, or to assume quantitative, differ- ences in intelligent performance, but that the human intellect is distinguishable by the capacity of language.

Euan Macphail argues that language plays such an important role in human problem-solving as to render it impossible to estimate general intellectual capacity in humans independent of language. The evidence for language-acquisition in apes is well reviewed and then discounted. If humans possess a species-specific language- acquisition device then it has evolved incredibly quickly because no one language is seemingly more primitive than any other.

In general, though this book is undoubtedly a good wade through the literature, it is not an easy read. As a review it provides ready access to the material; as a piece of sparkling and thought-provoking writing it fails.

S~AN MURPHY Brain Research Group, Open University, Milton Keynes, MK7 6AA, U.K.

Ethology: the Mechanisms and Evolution of Behavior. By JAMES L. GOULD. London: W. W. Norton (1982). Pp. 544+A61. Price s

As every lecturer knows, the perfect textbook exists only in the imagination - - it is the book that he would write himself if only he had the time. Given the diversity of topics covered by modern ethology no single textbook is going to provide a balance of content that is universally pleasing, and indeed there are aspects of Gould's book that by no means match my own view of the subject. Nevertheless this is overall a very fine book, and one that I would be proud to have written myself.

Unlike most recent ethology textbooks, Gould's really does make an effort to cover the whole range of ethology. Roughly equal space is devoted to causation, ontogeny and evolution, though in keeping with the current trend these three essentially separate aspects of behaviour are discussed in an explicitly evolutionary context which makes them appear more closely linked than perhaps they are. In other words the aspect of behaviour that is most frequently stressed, and that forms the focus of interest throughout the book, is its adaptiveness as a product of evolution.

Successive sections of the book deal with: (1) Neural mechanisms of sensation; (2) The causal basis of complex behaviour including fixed action patterns, orientation and communication; (3) Learning; (4) Behaviour genetics; (5) Evolutionary mechanisms; and (6) Social behaviour, including chapters on bees, ants, ungulates, carnivores and primates. In addition the book begins with an historical introduction and ends with a section on human ethology. The most obvious lacuna in this list of contents is that the area of ethology that used to be labelled 'motivation', and that now tends to be referred to in terms of 'decision making', makes a purely token ap- pearance. There is, for example, scarcely any mention of the hormonal control of behaviour, or of the control of feeding, drinking, sexual behaviour and aggression. This is an omission that many lecturers, especially on this side of the Atlantic, may regard as serious.

The book is stunningly well written and well produced: it is a joy to look at and an even greater joy to read. It is also impressively up to date on the topics with which it deals, though for my taste it presents a picture of ethology which is too smooth and uncritical. Rather in the manner of a Scientific American article, stories are presented as

more complete than they really are, and contradictory points of view tend to be omitted. The strength of this level of writing is that it is intelligible and appealing, especially to students who are making their first contact with the subject; the weakness is that it does not en- courage an inquiring attitude on the part of the reader. Furthermore there are no references in the text, so if one comes across a statement with which one might wish to take issue (and it is a very opinionated book) one has no way of knowing wb_ere Gould got his information from. There is a section of 'Further Reading' at the end of each chapter and a more extended bibliography at the end of the book, but the references given are mostly to secondary sources.

Like all the best and most exciting textbooks, Gould's presents a very tight, personal view of its subject matter: specifically, the theoretical standpoint is a traditional Lorenzian one retranslated into computer jargon. Gould puts his cards on the table by defining ethology as the study of instinct, and ethologists as those who 'believe that the secrets of behaviour lie largely in an animal's genes' (page 5). Instincts consist of fixed action patterns (or 'motor programs') triggered by releasers, and the general view of animals that emerges is of robots genetically pre- programmed by often very simple sets of rules. Gould is fond of talking about 'mindless behavioural subroutines', and the following seems to encapsulate his view about how behaviour is organized and how it should be studied : 'The ethological view of parenting is clear enough: chicks are programmed to get food from their parents and parents are programmed to provide it. All that remains to be discovered are the relevant releasers' (page 62). Similarly Gould's recipe for understanding human be- haviour is that 'We should be treating ourselves as one of many interesting species and looking hard for putative releasers, critical periods, drives, cases of imprinting, motor programming, and so on' (page 541).

This kind of thing ensures that one will not fall asleep while reading the book, but do the massive generaliza- tions really stand up to critical analysis ? Of course many of them do not, but the impression given by much of the book is that the author is not really interested in critical analysis: the terminology is used with virtuosity and with bravado, but in the long run it is used in a way that tends to slam shut, rather than to open up, the door to further discussion. Gould's use of the term instinct, for example, confounds a variety of causal, developmental and evolu- tionary properties of behaviour that have no logical con- nection: yet there is no attempt to define the term or even to suggest that there may be problems attendant on this usage. Rather, the existence of instincts is taken as self- evident, and instinct-spotting is presented as the main end of ethology. In the same way, by saying that behaviour is programmed, Gould gives the impression that a solution has been found to all the important problems about how behaviour works.

To summarize: this is above all a superbly well written book, which as an introductory text is stimulating, up to date, and as comprehensive as one could reasonably expect. It does however present a one-sided view of ethology: one that is in keeping with the times but which in my view will ultimately prove to have been hopelessly oversimplified.

T. J. ROPER

School of Biology, University of Sussex, Brighton BN1 9QG, U.K.