Females of the Species by Bettyann Kevles (Harvard University: $20; 251 pp., illustrated)
One reason why animal behaviorists, ethologists, and comparative psychologists ignored females for many years in their scientific studies of sexual behavior is that the males usually upstaged the females. In many species, males are showier, more colorful, more active and blatant in displays and vocalizations. Clearly, they are easier to observe, and it is easier to measure their behaviors. Accordingly, many popular books of the 1940s, ‘50s and ‘60s about sex behavior in animals are male-based and incidentally were written mostly by men.
The 1970s, however, saw the beginning of a turnaround, a groundswell of interest in the female partner, a recognition that it takes two to tango and that the female leads many of the steps. Now we realize that the female plays a central role in sexual behavior and ultimately in the evolutionary direction of the species. She is not a passive egg waiting for sperm penetration, but an often active pursuer of the male, who resorts to a vast array of behaviors to get her eggs fertilized and rear her young.
Bettyann Kevles, a science writer for the Los Angeles Times, has chronicled the recent plethora of experiments and observations in a comprehensive, encyclopedic book about female behavior in many species (not including the human). Her love of the subject, desire for accuracy and scholarly interest come forth in the selection of subject matter; in the monumental bibliography, more than 250 references of which many were written after 1980; in the six-page glossary, and in the thanks extended to many eminent scientists who reviewed chapters, discussed theoretical considerations and guided her to sources of scientific data.
Two main points emerge from this compendium: first, that there is no classic female type; and second, that females through their behaviors reflect their biological mandates and their adaptations to the demands of their own micro-ecological niche. Thus, although females of many species are gentle, nurturing and cooperative, those of some species show traits undesirable by human standards, like irresponsibility, viciousness, aggressiveness, competitiveness and deviousness; they will stop at nothing to mate with desirable males, to get more or better space, to obtain food for their developing offspring, and to maintain their status. The female of some species of firefly, for example, lures the male of other species with a simulated species code and, when the lured male nears the deceptive female, eats him, to nourish her developing eggs with more protein.
Kevles has divided her book into four major sections; courtship, mating, motherhood and sisterhood. Courtship and mating are really a continuum, but she separates the two for ease of explanation.
In courtship, the female chooses by measuring and comparing males. The female lyrebird, for example, evaluates males not by the shape or color of their magnificent tail feathers but rather by their length. As the male ages, his tail grows longer, ergo the older, longer-living male gets chosen more frequently as consort and may give the female’s offspring one genetic step up on the survival ladder. Among English moorhens, the fattest males are the most desirable, and the females even fight over them. Evidently, a fat male makes a better incubator since he doesn’t have to leave the nest to feed. Among other species, females check out nest construction, the pleasing vibrations sent by way of a web, or the kinds of gift the males bring. Some females, like the purple-throated hummingbird, offer copulation in exchange for dinner.
In the section on reproductive strategies, an inordinate amount of space is given to the relatively rare hermaphrodites and to females that switch their sex. There, Kevles also discusses how males transfer sperm: Orangutans hang from trees and face each other; opossums hang upside down from a branch; bees connect in mid-air; whales that breech the water as they copulate, etc. (Much of this is more amusing than relevant.)
Within strategies, estrous, timing, seasonality and mating systems (e.g. monogamy, polygamy, and promiscuity) are also discussed. However, Kevles does not thoroughly explain the adaptive value of female promiscuity and overlooks the shiner perch, one of the first fish species in which female promiscuity was verified through biochemical tests.
Finally we get to motherhood and sisterhood; that is, to parent-offspring relations and peer interactions. The range of behaviors shown by mothers is extreme. Female oysters abandon their eggs to the ocean tides; other females build or tend nests or carry their eggs about on or in their bodies. Maternal bonding is also variable. Female mammals behave differently with their daughters than they do with their sons. The females of some species, like the marmoset and the titi monkey, turn over care-taking entirely to the males. The babes are delivered back to mother only at nursing time. Female lions abort their fetuses when a new male enters the pride. Afterward, the females come into estrous, the new male inseminates them and the young are born synchronously. Feral horses have been observed to do the same. However, this major physiological upheaval appears to be more a male strategy than a female one.
In the section on sisterhood, Kevles writes about females that cooperate to look after offspring other than their own; female giraffes, for example, operate veritable “child care centers.” Then she considers females who do not mate but reproduce parthenogenetically. Most fascinating is the finding that among whiptail lizards, females mimic males during mating, and eggs are not produced unless one partner behaves like a male. Thus, even though they are without sperm, these females are not without male behavior as a stimulant to reproduction.
But Kevles closes her incredible compendium with the standard, cautious, deja vu statement, “what these studies do offer us is insight into the behaviors and the chemistries of other species so that we can learn about the forces that shaped our own (evolutionary) development.” Which is apparently to say: “We have learned something from animal studies; females of all other species are impelled to follow their biological mandates and ecological dictates, we as humans are free, and our choices are vast.
Not quite detailed enough to make a scientific reference, this book is too technical for the average reader who is not well grounded in biology. It will, however, make an excellent source book for courses in introductory biology and animal behavior, and I for one hope that it will find a place in women’s studies programs as well.
