Bruce Bagemihl - Biological Exuberance

101

In this regard, homosexual activity in some species is also claimed to be “caused” by unusual or abnormal environmental or climatic conditions, such as severe winter snowstorms that disrupt “normal” pairing in Golden Plovers (Nethersole-Thompson and Nethersole-Thompson 1961:207–8), or exceptionally rainy seasons that somehow “overstimulate” Ostriches (Sauer 1972:717) Assuming that ecological factors of this sort could be involved (which is debatable), an equally valid interpretation is that such species possess an inherent flexibility in their social and sexual systems that manifests itself during times of ecological flux or stress. Rather than being the “product” of “abnormal” conditions, then, such behavioral plasticity allows the species to respond “creatively”—in ways that, obviously, are not yet fully understood—to the vagaries of an ever-changing environment. See chapter 6 for further discussion.

102

Cheetah (Herdman 1972:112, 123;Caro 1993:27–28, 1994:362; Ruiz-Miranda et al. 1998:1, 13). For more on the false dichotomy of “wild” versus “captive” studies of animals, and the general compatibility and continuity between the two, see de Waal 1989a:27-33, 1997:11 (Bonobo).

103

Boto (Best and da Silva 1989:12-13); Orang-utan (van Schaik, C. P., E.A. Fox, and A. F. Sitompul [1996] “Manufacture and Use of Tools in Wild Sumatran Orangutans: Implications for Human Evolution,” Naturwissenschaften 83:186-88); Savanna (Olive) Baboon (DeVore, 1. [1965] “Male Dominance and Mating Behavior in Baboons,” p. 286, in F. A. Beach, ed., Sex and Behavior, pp. 266-89 [New York: John Wiley and Sons]); Thomson’s Gazelle (Walther 1995:30-31); King Penguin (Gillespie 1932; Stonehouse 1960); Black-headed Gull (Kharitonov and Zubakin 1984:103; van Rhijn and Groothuis 1987:144); Flamingo (Cézilly and Johnson 1995).

104

Griffon Vulture (Blanco and Martinez 1996:247; Sarrazin et al. 1996:316); King Penguin (Weimerskirch et al. 1992:108); Gentoo Penguin (Williams and Rodwell 1992:637; Bost and Jouventin 1991:14); Flamingo (A. R. Johnson, personal communication); Dugong (Anderson 1997:440, 458; Preen 1989:384). See also chapter 3 for further discussion of heterosexual bias in the methods of sex determination employed during field studies of these and other species.

105

Canids (Macdonald 1980, 1996); Macaques (Oi 1990a; Reed et al. 1997); Gibbons (Fox 1977; Edwards and Todd 1991); Rose 1992:1-2 (Killer Whale); Aperea (Rood 1972:42); Rufous Bettong (Johnson 1980:347).

106

Orang-utan (Schürmann 1982:270-71, 282); Oystercatcher (Angier, N. [1998] “Birds’ Design for Living Offers Clues to Polygamy,” New York Times March 3, pp. B11–12).

107

van Lawick-Goodall, J. (1970) “Tool-Using in Primates and Other Vertebrates,” p. 208, Advances in the Study of Behavior 3:195-249.

108

Sage Grouse (Scott 1942:495); Rhesus Macaque (Carpenter 1942:150); Fat-tailed Dunnart (Ewer 1968:351); Long-eared Hedgehog (Poduschka 1981:84); Takhi (Boyd 1986:660).

109

Common Garter Snake (Noble 1937:710–11); Hooded Warbler (Niven 1993:192).

110

African Elephant (Sikes 1971:265–66); Snow/Canada Goose (Starkey 1972:456–57).

111

Western Gull (Wingfield et al. 1982); Ring-billed Gull (Kovacs and Ryder 1985). See also the examples of more “intense” nesting behavior in female pairs of Ring Doves and Budgerigars discussed in note 15, chapter 1, which might also be correlated with hormonal effects.

112

For a summary of these results, see Vasey, P. L. (1995) “Homosexual Behavior in Primates: A Review of Evidence and Theory,” International Journal of Primatology 16:173–204. Some of the species in which hormone levels have been studied in association with homosexual behavior are Rhesus Macaques (Akers and Conaway 1979; Turner et al. 1989) and Hanuman Langurs (Srivastava et al. 1991). (Turner, J. J., J. G. Herndon, M.-C. Ruiz de Elvira, and D. C. Collins [1989] “A Ten-Month Study of Endogenous Testosterone Levels and Behavior in Outdoor-Living Female Rhesus Monkeys [ Macaca mulatta ],” Primates 30:523–30.) For a discussion of the problematic nature of studies on laboratory rats that purport to show an association between homosexual behavior and hormones, see Mondimore, F. M. (1996) A Natural History of Homosexuality, pp. 111–13, 129–30 (Baltimore: Johns Hopkins University Press); Byne, W. (1994) “The Biological Evidence Challenged,” Scientific American 270(5):50–55.

113

Pied Kingfisher (Reyer et al. 1986:216); Orang-utan (Kingsley 1982:227); Spotted Hyena (Frank 1996; Frank et al. 1985, 1995 ; Glickman et al. 1993); Western Gull (Wingfield et al. 1982). See also Mloszewski (1983:186), who indicates that masculinized female African Buffalo—i.e., those with “pronounced male secondary sexual characteristics,” likely due in part to a differing hormonal profile—do not participate in homosexual activity any more often than do nontransgendered females (and perhaps do so even less often). For other species in which a subset of individuals have different hormone profiles (not associated with homosexual activity), see Solomon, N. G., and J. A. French, eds. (1997) Cooperative Breeding in Mammals, pp. 241, 304–5, 370 (Cambridge: Cambridge University Press).

114

Takhi (Boyd 1986:660). Although detailed hormonal studies of Takhi during pregnancy have been conducted, they did not involve sampling of androgens or other male hormones; see Monfort et al. 1994; Monfort, S. L., N. P. Arthur, and D. E. Wildt (1991) “Monitoring Ovarian Function and Pregnancy by Evaluating Excretion of Urinary Oestrogen Conjugates in Semi-Free-Ranging Przewalski’s Horses ( Equus przewalskii ),” Journal of Reproduction and Fertility 91:155–64.

115

Domestic Horses (McDonnell, S. [1986] “Reproductive Behavior of the Stallion,” especially p. 550, in S. L. Crowell-Davis and K. A. Houpt, eds., Behavior, pp. 535–55. Veterinary Clinics of North America: Equine Practice 2[3] [Philadelphia: W. B. Saunders]).

116

Recent work on the sexual orientation of Domestic Sheep has begun to move away from this paradigm, to the extent that hormonal profiles are assessed for males who prefer mounting other males, rather than simply for the (“gender-atypical”) males who are themselves mounted by other males. In this case, there do appear to be some differences between homosexual and heterosexual sheep (cf. Adler, T. [1996] “Animals’ Fancies: Why Members of Some Species Prefer Their Own Sex,” Science News 151:8–9; Resko et al. 1996; Perkins et al. 1992, 1995). However, rarely (if ever) is the two-way influence of biology and behavior discussed in these studies, i.e., biology (hormones, brain structure) is invariably assumed to determine sexual behavior, when in fact it is also possible for behavior (and other social factors) to alter or affect an animal’s hormonal profile or brain structure. Moreover, the search for hormonal differences is little more than a continuation of the need to find a physiological “cause” for homosexuality. Within an overall framework in which any nonreproductive behavior is still seen as anomalous, this is only a few steps removed from the overt pathologizing of homosexuality so characteristic of earlier studies.

117

Savanna Baboon (Marais 1922/1969:205); Baker, J.R. (1929) Man and Animals in the New Hebrides, pp. 22, 117 (London: George Routledge and Sons).

118

Bighorn Sheep (Berger 1985:334–35); White-tailed Deer (Thomas et al. 1964:236; see also Taylor et al. 1964; Thomas et al. 1965, 1970); Savanna Baboon (Marais 1922/1969; Bielert 1984b, 1985).

119

For early descriptions of intersexual Savanna Baboons, see Marais 1922/1969, 1926. For a summary of early observations of velvet-horns and other gender-mixing Deer, see Thomas et al. 1970:3 (White-tailed Deer) and Anderson 1981:94–95 (Mule Deer).