Foraging for Survival: Yearling Baboons in Africa

Rating:
Summary: This is a great book intended to ecology specialists
Review: A review of this book has been published in the following journal:

Houle, A. (1999). Book-Review: Foraging for survival: Yearling baboons in Africa. Behavioural Processes. (in press)

Rating:
Summary: This book is destined to become a classic in primatology.
Review: This is a story of how eleven juvenile baboons feed themselves. The setting: Amboseli National Park, Kenya. This is, however, much more than a simple story. Throughout, Altmann engages the reader with his elegant analysis - rich with ecological detail - of the costs and benefits primates must negotiate in their daily pursuit of requisite nutrients and energy. Baboons are exemplary eclectic omnivores; still, as Altmann quotes, "there is no such thing as a free lunch." Bearing this in mind, he sets out to evaluate the balancing act baboons must achieve in maximizing nutrient intake, while at the same time minimizing toxic accumulation of plant secondary metabolites.

At the outset, Altmann describes what the baboons ate, how they ate it, and what foods they avoided altogether during the study period (1975-1976). He then identifies what baboons should eat. A foraging strategy is an ultimate endpoint, achieved via an array of potential tactical routes. Altmann evaluates both the feeding tactics and the eclectic foraging strategy of his young baboons by identifying the degree to which they deviate from an optimum model of adaptive feeding traits. The baboons' actual dietary intake is compared to the specifications of adequate and optimal diets; this is done for both an average yearling's diet, as well as on individual variance from the predicted diets.

Deviations from the optimum are viewed as indicators of potential differences in reproductive fitness. Although the feeding data stem from research undertaken in the mid-1970s, Altmann takes advantage of the two succeeding decades to relate differences in juvenile diets to longevity and fitness outcomes later in life. This historical depth is particularly valuable because it tests the model by evaluating whether those baboons that come closer to the optimum as juveniles have higher fitness as adults.

Altmann expands on the extreme selectivity exhibited by baboons, providing details on the toxic load, protein, carbohydrate, water content, and load of various plant species and the manner in which baboons maximize (or minimize) their intake of these food components. Finally, he assesses the anatomical and behavioral attributes that may contribute to making baboons one of the most successful and broadly distributed primate species. To complement the main body of the text, Altmann includes a series of appendices and tables in which he evaluates various methodological and definitional issues relating to calculating feeding bouts and dietary intake. Here, he presents additional detail on diet composition and the nutritional and toxic attributes of plant foods.

The work's emphasis on juvenile feeding behavior is an unusual yet valuable feature. This developmental stage is often overlooked in studies of non-human primate behavior and ecology, despite the fact that this period, and the transition from a milk diet to an adult diet, are undoubtedly critical to our understanding of adult fitness and life history patterns.

However, some caution is warranted: This book was not intended for the casual student of animal feeding behavior, nor for those new to optimal foraging theory. Altmann's models, food intake calculations, and feeding bout formulae are exacting, and quite abstracted from the experience of observing feeding behavior. Before embarking into this volume, non-modelers will have to review the technical terminology that necessarily accompanies Optimization Theory. In addition, I do not view the generalizations (outlined in Chapter Two) based on the relationships among body size, patch size, and dietary selectivity to be particularly illuminating. Too many exceptions to his proposed relationships can be found for such generalizations to be of much explanatory utility.

Nonetheless, this book is destined to become a classic in primate feeding behavior. It is exhaustive in its breadth, a pleasure to read, and sets the standard for amalgamation of modeling theory and ecological observation.