Current Ornithology, Volume 13

Current Ornithology, Volume 13.-Val Nolan, Jr. and Ellen D. Ketterson (Eds.). 1996. Plenum Press, New York. 359 pp. ISBN 0-306-45473-4. Cloth, $89.50.-This volume, like those before it, contains a grab bag of reviews covering topics from cognition to chemical defense to effects of birds on agricultural pests. Although this volume is somewhat uneven, its six chapters are likely to be as influential as ornithological readers have come to expect from this series.

Titillatingly entitled "Social Cognition: Are Primates Smarter than Birds?," Chapter 1 compares the evidence for thinking in birds and primates in the areas of cultural transmission of behavior, tool use, cooperation, complex social cognition (e.g. an individual's familiarity with conspecifics and their past behavior toward him or her), and communication. Peter Marler makes the compelling case that, to the best of our knowledge, avian cognition is on a par with that of infrahuman primates in most of these areas. Perhaps as surprising as the relatively strong cognitive abilities of birds is the fact that the data the author discusses-like tits (Parus caeruleus and P major) pecking through bottlecaps for cream, Egyptian Vultures (Neophron percnopterus) dropping rocks on eggs, and Harris's Hawks (Parabuteo unicinctus)hunting cooperatively-are well known to students of bird behavior. The author's contribution, of course, is the interpretation of these studies not as behavioral oddities, but as indications of avian cognition. I am certain that, after reading Marler's review, many people will be convinced of the need to study the proximate causes of avian social behavior with an eye toward cognition. The paper seems destined to be read widely by ornithologists and primatologists alike, most of whom will feel richly rewarded for their trouble.

Chapter 2 is Russell Balda, Alan Kamil, and Peter Bednekoff's paper entitled "Predicting Cognitive Capacity from Natural History." Based on the subject matter, this chapter is well positioned after Chapter 1. Being somewhat ponderous and repetitive, however, Chapter 2 suffers in comparison to the crisp, highly readable prose of the first chapter. The authors' main contribution is to offer their own highly successful research program as a model for how the comparative method can advance the study of avian cognition. I appreciated their efforts to highlight potential trouble spots, both technical and conceptual, with cognitive work of this kind. Despite its weak presentation, this article seems likely to achieve its goal of encouraging others, principally behavioral ecologists, to attack cognitive issues with similar approaches.

The third chapter is Margaret Brown's "Assessing Body Condition in Birds." Brown does a competent job of giving a historical perspective on studies of this topic and reviewing the wide variety of techniques used in determining body condition in birds. Here again, however, weak presentation-particularly verboseness and overuse of the passive voicebogs down the review. A second concern was the curious decision of the author to restrict her literature survey to 13 ornithological, ecological, and physiological journals, which ensured that a number of important papers on body condition would be missed. Nonetheless, the review is timely and will be useful to avian ecologists and physiologists faced with the vexing problem of assessing body condition.

Chapter 4, "Avian Chemical Defense" by John Dumbacher and Stephen Pruett-Jones, is a well written and compelling call for more attention to the use of chemicals by birds in defending themselves and their nests. Coming in the wake of the exciting findings of neurotoxins in various species of Pitohui, this review could hardly be more timely. The authors pull together a good many cases of known or suspected avian chemical defense in birds. Although they caution readers that many cited examples are anecdotal (e.g. based on unpalatability of birds to humans), the sum of their efforts is convincing: avian chemical defense is a largely overlooked topic worthy of study. This chapter will be of interest to all ornithologists and certainly will inspire rigorous investigation of chemical defense by behavioral and chemical ecologists.

Most distinct from the rest of the volume in terms of subject matter is Chapter 5, "Past and Current Attempts to Evaluate the Role of Birds as Predators of Insect Pests in Temperate Agriculture" by David Kirk, Matthew Evenden, and Pierre Mineau. Every bit as lengthy as its title portends, this article is generally well written but a bit overambitious. It contains discussion interspersed with detailed case histories of economically important pests; quasi-biographical sketches of early students of avian effects on crops; lengthy summaries of the methods, results, and conclusions of some important studies; and even passages dealing with the possible relevance of social dominance and optimal foraging to avian predation on crop pests. Although I found the review to be a hodgepodge, the authors' historical treatment of the topic was fascinating and useful. Likewise, their main points-that birds are potentially important consumers of agricultural pests and that farmland should be laid out with this positive influence in mind-come across well. Although this article is more vital to those in the agricultural community than to dyed-in-the-wool ornithologists, it will be eye opening to the latter group as well.