Evolution's Rainbow. Joan Roughgarden

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СКАЧАТЬ tail of the courted individual, resulting in a ball of writhing snakes.

      Females have special lipid perfumes in their skin that turn males on. In 1985 some male garter snakes were found with female perfumes in their skin. Of two hundred mating balls, about 15 percent consisted of a male, presumably with female perfumes in his skin, surrounded by courting males. The males with female perfumes were called—you guessed it—female mimics. The feminine males who joined female-centered mating balls in progress were thought to be distracting the males already there, thus giving themselves greater access to the female.

      As with the other claims of female mimicry, the story had internal contradictions. In choice experiments, the males preferred a female to a feminine male, showing that males could tell the difference—they were not deceived. Moreover, in 2000 it was found that all male garter snakes have female perfumes when they emerge from the den in the spring and that all males court these perfumed males in addition to females. At this point, the investigators floated four deceit-based theories to explain why all males have female perfumes on emergence: (1) a perfumed male may confuse the other males while carrying out his own mating; (2) the perfumed male may avoid wasting energy in courting before he has fully awakened from hibernation; (3) a perfumed male may induce the other males to waste time and energy courting him while he gets ready to start his own courting; and (4) a perfumed male may distract other males from the females so he has more to himself when he does get going.

      The investigators discarded what seems like an obvious hypothesis. Imagine you’re a male garter snake just waking up in the spring. You’re chilly and covered with cold dirt and mud. You see a spot of blue sky through the ceiling. You crawl out and are greeted by the smiling faces of ten horny males hoping you’re a female. You’re not. But they’re hot and fast, and you’re cold and slow. Wouldn’t it be nice to roll around in the sun—why not use some perfume to signal your intentions? And if you’re one of the ten males watching this face poke up through the ground, and you see he’s not the female you were waiting for, why not welcome him into the sunlight and get acquainted? Better than attacking him, with nine of your buddies looking on ready to attack you too.

      This explanation, that the female perfumes might protect a male from attack when he is emerging, was dismissed because garter snakes just aren’t “agonistic.” By nature they’re friendly. Indeed, they’d better be, with twenty thousand of them in one spot! But why are they so “notoriously amorous”? And what makes them so friendly? Group sex.

      

      These studies are disturbing because they attempt to sensationalize at the expense of transgendered people. An article in the scientific journal Animal Behaviour begins, “Female mimicry, whereby a male takes on a female’s appearance, is a rare but widely publicized trait in human societies. Remarkably, parallels can be seen in other animal species.” Feminine males and masculine females are not rare among humans. Nor are transgendered people comparable to snakes. All male garter snakes wear female perfume and participate in same-sex copulation every year. No human society has ever enjoyed such a rite of spring! An article in another scientific journal, the Canadian Journal of Zoology, refers to female mimicry as “bizarre.”²⁸ The problem with female mimicry is not that it is bizarre; the problem is that female mimicry is a myth.

      Both articles refer to feminine males in text and figure captions as “she-males.” This language, derived from pornography, is derogatory. A she-male is a woman with a penis. The transgender community has better words to describe transgendered bodies. In the biological literature expressions like “gynomorphic male” and “andromorphic female” are preferred when describing a feminine male or a masculine female.²⁹

      The articles derogate not only transgendered people but also their partners. The title of one article includes the phrase “transvestite serpent,” and another claims to be about the “behavioural tactics of ‘she-males’ and the males that court them.” This writing not only stigmatizes transgendered people with certain body types, but also transfers the stigma to their friends. I hope future work on these animals is carried out with more professionalism, and that future publications on this subject receive better editorial oversight.

      The examples just cited involve males whose appearance is somewhat feminine. A different kind of example, involving a male bighorn sheep that is morphologically indistinguishable from other males but quite different behaviorally (called an “effeminate male”), might also have been discussed here (see chapter 8). What seems common among all these feminine males is a lessening of hostilities. The cessation of hostility may be temporary, as in garter snakes, or last a year or so, as in young birds whose juvenile color matches the color of females, or be permanent, as in the sunfish cooperator morph whose occupation is to assist controller males in their courtship. The feminine males may exhibit a distinctly feminine signal, such as colored bars or stripes, or simply share with females the absence of the threatening colors of controller males. In either case, feminine imagery seems to be adopted by males to reduce hostility and promote friendship.

      Overlooking the positive value of feminine males is part of a larger problem of overlooking cooperation among animals. Even apart from gender expressions, many forms of cooperation occur. Let’s look at a few more.

      FRIENDLY FISH

      Books on fish behavior are the ponderous rivals of telephone directories. Without going into extensive detail, a few more examples are worth noting to fill out some missing colors in the rainbow of fish gendering.³⁰

      Some species don’t bother with a controller morph. Instead, they spawn in large groups of two genders—just male and female. Simple. In surgeonfish, thousands of individuals aggregate for one giant love feast. Other species spawn both in pairs and in groups.³¹

      In the bluehead chub (Nocomis leptocephalus), males form partnerships to build nests together. Two large, individually recognizable males were observed together building five different nests in succession. Males of the northern greenside darter (Etheostoma blennioides) form partnerships to court females. Several species of temperate freshwater fish carry out joint courtship, including lake trout (Salvelinus namaycush), the yellowfin shiner (Notropis lutipinnis), and the sucker (Moxostoma carinatum). In many species of suckers, spawning appears to occur only in trios. Two male spawning partners adjoin the female on either side and press against her flanks. This formation is aided by breeding tubercles, called “pearl organs,” which roughen the body surface of males so that the three fish can hold position and not slip apart.

      Males in some species, such as the Mediterranean peacock wrasse (Symphodus tinca) — “hot bed,” that is—lay eggs in a nest while the nest owner is between spawning periods. For some reason, biologists term this nest sharing “piracy,” again reflecting a preoccupation with theft. In the tesselated darter (Etheostoma olmstedi), a male who spawns in a breeding hole abandons it to find another one. Another male takes over the nest and cares for the eggs, including cleaning and guarding them.³²

      

      Some species show cooperative brood care in extended families, just as in the extended families of birds with postzygotic helping at the nest: Lamprologus brichardi, a small fish from Lake Tanganyika, is one of six species there exercising cooperative brood care.³³ There is even cross-species brood care! All broods older than five weeks guarded by Midas cichlids (Cichlasoma citrinellum) in Central America contained young of Neetroplus nematopus in addition to their own, and conversely, some guarded broods of Neetroplus nematopus contained young of the Midas cichlid.³⁴

      All in all, fish show lots of cooperation. Although not my first choice, I could live with being a fish.

      BIASED VOCABULARY

      Silent bullfrogs, antlerless deer, and small, medium, and large male sun-fish are happily ignorant СКАЧАТЬ