Biological Exuberance: Animal Homosexuality and Natural Diversity

More generally, a number of scientists have suggested that the term homosexual should be reserved for overt sexual behavior, and that it is inappropriate to apply this word to other behavior categories such as same-sex courtship, pair-bonding, or parenting arrangements. We might characterize this as a “narrow” definition of homosexuality (such as that assumed by Lorenz). On the other hand, homosexuality, as the term is used in this book, refers not only to overt sexual behavior between animals of the same sex, but also to related activities that are more typically associated with a heterosexual or breeding context. This usage is consistent with a number of studies in the zoological literature, in which the word is employed as a cover term for both sexual and related behaviors (e.g., courtship, pairing, parenting).⁴⁶ We might characterize this as a “broad” definition of homosexuality. Although overt sexual behavior is by far the single most common type of same-sex activity found in various species—hence the original terminology—the other behavior categories also occur in a sizable proportion of cases in which same-sex activities have been documented. In many (but not all) species, behaviors of various categories co-occur (e.g., sexual and courtship activity with pair-bonding, courtship or bonding with parenting, and so on). There are also numerous cases where only one behavior type is instantiated, or where several behavior categories co-occur in the same species but are not necessarily observed in the same individuals (e.g., sexual behavior may be seen between some animals, courtship behavior between others, etc.). In some cases this represents actual discontinuities of behaviors; in others, it represents observational gaps. When the term homosexuality is employed in the broad sense for these cases, it is always with the understanding that only selected behavior categories or co-occurrences may be involved (as in observations of heterosexual behavior).⁴⁷

The difference between these two usages of the term homosexual can be illustrated with an example involving two different forms of same-sex activity (each widely attested in birds, sometimes both in the same species). On one hand, consider two female birds that are pair-bonded to each other for life, regularly engage in courtship activity with one another, build a nest each year in which they jointly lay eggs, and on one occasion raise chicks together (fathered via a single heterosexual copulation that season by one of the partners), yet never mount each other. On the other hand, consider a male bird who is mated to a female partner for life—with whom he regularly copulates and raises offspring—but who participates in a single copulation with another male (and never again engages in such behavior for the remainder of his life). A narrow definition of homosexuality would require us to consider the first case to be somehow less “homosexual” than the second simply because no overt sexual behavior takes place between the two females. A broad view of homosexuality, on the other hand, recognizes that both cases involve homosexual behavior—but of two distinct types that need to be carefully distinguished in terms of their social context as well as the other sexual and pairing activities of the participants (since both scenarios actually exemplify contrasting forms of bisexuality). Unlike the narrow definition, this usage acknowledges the complexities and variability of same-sex interactions in the animal world, while providing a useful framework for cross-species comparisons and generalizations; it also offers the possibility of more precise and nuanced characterizations of sexual orientation.

Most scientists are understandably wary of anthropomorphizing animals with terms that have wide applicability in a human context—as well they should be—and obviously not all zoologists who avoid the word homosexual are motivated by homophobia. Nevertheless, the lengths that are taken to circumvent terminology that can easily be clarified with a simple explanatory statement often border on the absurd.⁴⁸

“Not Included in the Tabulated Statistics”