Read Online Dr. Tatiana's Sex Advice to All Creation by Olivia Judson - Free Book Online Page B

lay all their eggs in one place as pollinators do but instead can lay a few eggs in many. At the right time of year, you can see speckles on the fig skins from the drilling of different females.
    Spreading a brood among several figs will have one of two consequences. In species where population densities are low, males risk finding themselves alone in a fig. So it is not surprising that where this is likely, males have wings so that they can fly off to
search for lovers outside the fig of their birth. But in species—and yours is one—where figs tend to be crowded, males do not fly. Any given fig will probably also be home to mates. The trouble is, of course, it will probably also be home to rivals. Hence the slaughter.
    Mortal combat is an effective but risky way of eliminating rivals. Males are not usually interested in fighting to the death unless they have a lot to gain—and little to lose—by doing so. Dying, after all, precludes further reproduction. Thus, lethal fighting is most likely to occur in species like yours that live for only one breeding season. One-shot breeding does not by itself, however, produce routine violence. Two other factors are crucial. First, receptive females must be clumped in space and time such that a fellow’s only chance to mate is here, now. Second, fighting must increase the number of females he can mate with: there is no point wasting time fighting if in doing so he is missing out on sex. For example, if females are abundant but they mate only once, then males who copulate will do better than males who fight—a dynamic thought to explain why fighting is virtually unheard of among pollinator wasps.
    Only a handful of other creatures have a reputation for extreme violence, and what little we know of them is consistent with this scenario. Take the “annual” fishes of Africa and South America. Their lifestyle is almost magical. They live in puddles, ponds, and ditches that dry up for part of the year. When the puddles dry up, they die. Only their eggs survive, buried under the dried mud, waiting for the next rains. Collect mud, add water—and presto, you get fish! You can see why people believed in spontaneous generation. When the rains come, time is short. As there is no chance to move to a new neighborhood, everyone tries to be the big fish in the small pond: the males of some of
these species are among the most pugnacious fishes known. If I had to bet, I’d predict that the more ephemeral the puddle, the fiercer the fighting.
    Or take gladiator frogs. These brown tropical frogs have evolved switchblades: on each hand, just above the thumb, males have a sharp, retractable spine that is shaped like a scythe. Most of the time, they keep it sheathed in folds of flesh. But when two male frogs fight, they rake these spines across each other’s faces, aiming for the eyes and eardrums of their opponent. Although we don’t know the death toll in the wild, we do know fights can be lethal. As you would expect, competition for mates is fierce. And also consistent with the hypothesis, gladiator frogs have short lives. Even without the fighting, few survive from one breeding season to the next.
    Perhaps the strangest example of violence is not from an animal but from a plant, the orchid Catasetum ochraceum, and its relations. In these species, female flowers receive pollen from only one pollinator. Immediately after pollination, they swell shut and set about making fruit. Competition between male flowers to be “the one” is therefore fierce. But since they are plants, they can hardly fight it out man to man. Instead, they direct their aggression at a hapless intermediary—a bee. The male flowers assault any bee who ventures inside them, throwing sticky sacks of pollen onto the bees’ backs. In one species, the flower throws the pollen at the staggering velocity of 323 centimeters per second. Since the pollen sacs are also large—they