Bruce Bagemihl - Biological Exuberance

34

It should also be reiterated that detailed longitudinal studies of breeding success and sexual orientation (comparble to that done on Silver Gulls) have not been conducted on any of these species to verify possible connections between bisexuality and reproduction. Moreover, all of these cases involve homosexuality among members of only one gender, which again is inconsistent with a “bisexual superiority” hypothesis.

35

Bonobo (Hashimoto 1997:12-13); Gorilla (Fossey 1990:460, 1983:74, 188-89); Squirrel Monkey (Mendoza and Mason 1991:476-77); Wolf (Zimen 1976:311, 1981:140); Common Tree Shrew (Kaufmann 1965:72); Bottlenose Dolphin (Ostman 1991:310). For arguments that this is not merely “displaced,” “redirected,” or “vicarious” heterosexuality (as Fossey [1990:460] and others have labeled it), see the discussion of the “shortage” hypothesis in chapter 4.

36

Guianan Cock-of-the-Rock (Trail and Koutnik 1986:215); Oystercatcher (Heg and van Treuren 1998:690; D. Heg, personal communication).

37

Kob (Buechner and Schloeth 1965:219 [table 2]).

38

Cattle Egret (Fujioka and Yamagishi 1981:136, 139 [including tables 1, 3, 4]).

39

See the profile of the Ruff for further details and illustrations.

40

Ruff (Van Rhijn 1991:87; Hogan-Warburg 1966:176).

41

Ruff (Lank et al. 1995). Nearly 30 years previously, Hogan-Warburg (1966) and van Rhijn (1973) had suggested that there might be genetic differences between various categories of males, based on the indirect evidence of their plumage and behavioral distinctions as well as the constancy of their category status. This hypothesis was subsequently confirmed by DNA and heredity studies.

42

Red Flour Beetle (Castro et al. 1994; Serrano et al. 1991); Fruit Flies (numerous references, summarized in Finley et al. 1997). See also Hamer and Copeland (1994) on the role of genetics in human homosexuality.

43

This has been suggested for species such as Stumptail Macaques, White-faced Capuchins, Killer Whales, Northern Elephant Seals, West Indian Manatees, Giraffes, Gray-headed Flying Foxes, Ring-billed Gulls, Black-headed Gulls, Ocher-bellied Flycatchers, Guianan Cock-of-the-Rock, Calfbirds, Superb Lyrebirds, and Adelie Penguins. In addition, in some species where homosexual behavior is classified as “play,” the implication is also that it functions as practice for “real” (i.e., heterosexual) activity.

44

Rhesus Macaque (Akers and Conaway 1979:76-77); Tree Swallow (Lombardo et al. 1994:556).

45

In a number of species, though, homosexual activity is restricted to juvenile or younger animals (see Dagg, “Homosexual Behavior and Female-Male Mounting in Mammals,” for a survey of such cases).

46

See Baker and Bellis, Human Sperm Competition , pp. 118-19, where this “explanation” is proposed for both humans and nonhumans.

47

Guianan Cock-of-the-Rock (Trail and Koutnik 1986:209, 215). These scientists admit that they have no specific data to support the conjecture that courtship interactions between males actually improve the subsequent heterosexual performance of younger males.

48

See below for discussion and refutation of the (related) idea that homosexuality is a form of courtship “disruption” in this species.

49

See Rose et al. (1991:188) for a statement to this effect concerning Northern Elephant Seals. The Ocher-bellied Flycatcher is another species where the relative infrequency of this behavior is curiously at odds with its putative “practice” function (see Westcott and Smith [1994:681] for the suggestion that courtship interactions between males in this species may allow younger birds to gain courtship experience).

50

Sage Grouse (Patterson 1952:153-54); Pandolfi, M. (1996) “Play Activity in Young Montagu’s Harriers ( Circus pygargus),” Auk 113:935-38.

51

For a similar conclusion regarding this “explanation” for primates, see Vasey, “Homosexual Behavior in Primates,” p. 192. See also Wagner (1996:212) on Razorbills.

52

The only example specifically involving females is the Ring-billed Gull, and notably in this case it is experience with parenting or pair-bonding, not sexual behavior, that females are claimed to acquire through homosexual partnerships (Fox and Boersma 1983:555).

53

On the myth of female passivity in sexual interactions, as well as the generally sexist interpretations of female behavior and physiology in this regard, see Eberhard, Female Control , pp. 34-41, 238, 420-21; Batten, M. (1992) Sexual Strategies (New York: Putnam’s); Gowaty, P. A. (1997) “Principles of Females’ Perspectives in Avian Behavioral Ecology,” Journal of Avian Biology 28:95-102; and the numerous other references in note 10, chapter 3.

54

For examples of scientists who have argued (or suggested) that homosexuality promotes or strengthens social bonds or general social cohesion and stability, see Kano 1992:192 (Bonobo); Yamagiwa 1987a:1, 23, 1987b:37, Robbins 1996:944 (Gorilla); Weber and Vogel 1970:79 (Hanuman Langur); Reinhardt et al. 1986:55 (Rhesus Macaque); Rose 1992:97—98, 116—17 (Killer Whale); Coe 1967:319 (Giraffe); Nelson 1965:552 (Gray-headed Flying Fox); Heg and van Treuren 1998:688, Ens 1998:635 (Oystercatcher); Sauer 1972:735 (Ostrich); Rogers and McCulloch 1981:90 (Galah). One scientist suggests that homosexual activity in Bonobos, although promoting bonding between same-sex individuals, actually serves a more important role in heterosexual relations: “Homosexual activity became a way of tying males and females together in larger aggregations” (de Waal 1997:138); for a refutation of this type of heterocentric interpretation, see Parish (1996:65). For examples of homosexuality claimed to be a strategy of alliance or coalition building, including for the purpose of acquiring heterosexual mates, see Kano 1992, Idani 1991 (Bonobo); Vasey 1996 (Japanese Macaque, other species); Bernstein 1980:40 (Stumptail Macaque); Smuts and Watanabe 1990 (Savanna Baboon); Colmenares 1991 (Hamadryas Baboon); R. Wrangham and S. B. Hrdy, in Weinrich 1980:291 (Gelada Baboon, Hanuman Langur); Wells 1991:218-20 (Bottlenose Dolphin).

55

See chapter 4 for further discussion and refutation of the idea that this is the motivation (or adaptive function) for homosexual associations.

56

Rhesus Macaque (Carpenter 1942:149); Bottlenose Dolphin (Wells 1991:220); both of these cases are highly speculative. The Rhesus example is based on an isolated observation of a single consortship and is a questionable interpretation, while the Bottlenose case is considerably more complex than it initially appears (see discussion below).

57

Parker, G. A., and R. G. Pearson (1976) “A Possible Origin and Adaptive Significance of the Mounting Behavior Shown by Some Female Mammals in Oestrus,” Journal of Natural History 10:241—45; Thompson-Handler et al. 1984:355-57 (Bonobo); African Elephant (Buss 1990); Greenshank, Golden Plover (Nethersole-Thompson 1975:55).

58

Species in which homosexual activity among females has only been reported outside the breeding season (or when females are not in heat) include Wapiti, Barasingha, Waterbuck, and Gray-headed Flying Foxes.

59

Japanese Macaque (Gouzoules and Goy 1983:47); Hanuman Langur (Srivastava et al. 1991:508).

60

Hanuman Langur (Srivastava et al. 1991:508); Calfbird (Trail 1990:1849-50); Cheetah (Caro and Collins 1987:59, 62; Caro 1993:25, 1994:252, 304); Savanna Baboon (Noë 1992:295). For specific descriptions of animals of the opposite sex being “disinterested” or not attracted by homosexual activity, see Gorilla (Harcourt et al. 1981:276); White-handed Gibbon (Edwards and Todd 1991:232—33); Japanese Macaque (Wolfe 1984, Vasey 1995:190; Corradino 1990:360); Killer Whale (Jacobsen 1986:152); Gray Whale (Darling 1978:51-52); Northern Fur Seal (Bartholomew 1959:168); African Buffalo (Mloszewski 1983:186); Rufous Rat Kangaroo (Johnson 1980:356); Dwarf Cavy (Rood 1970:442); Laughing Gull (Noble and Wurm 1943:205); Sage Grouse (Scott 1942:495).