Violation by Sallie Tisdale Page B

a trunk, and back a cow up to the opening on the other side. The cow holds still—usually with a placid patience but sometimes with a keeper’s encouragement—while the bull checks her urine and urogenital secretions with his trunk. Schmidt keeps track of the length of time the bull seems interested. “We didn’t know if the cows would get upset by being backed up to a bull, or what the bull would do, and so forth,” he told me. “It turned out that young Packy was quite interested in breeding and in the cows, and very happy to check them. And the cows, once they’d figured out what we were doing—well, it was fine with them, no big deal. I started to make daily observations, which we have done, with only a handful of missed days, since the fall of ’74.” Schmidt was surprised by what he found: peaks of intense interest in a particular cow for a few days, followed by months of indifference. “And these were known breeding cows,” he explained. “They’d all been pregnant and given birth, so they had estrous cycles. Something was fishy about the published estrous cycle. It sure couldn’t be twenty-two days.”
    Schmidt’s wife, Anne, who is a research biologist at the zoo, had done serum-hormone assays on the zoo’s African lions, and had mapped the lion ovulatory cycle by noting changes in the levels of hormones in the blood. She suggested that the same might be done with the elephants, and Mike began drawing blood from the cows. He used a vein in the leg or the ear, laboriously bleeding each cow himself once a week, until Roger Henneous couldn’tstand it any longer. “Roger said, ‘I could do that.’ I said, ‘Okay, Roger, go ahead,’ sure that he couldn’t. But damned if he didn’t get a vein the first time. After that, the keepers did it.”
    Over several months, Schmidt noticed patterns in the hormone levels, including a sixteen-week cycle of progesterone. The sniff-test results correlated with the progesterone cycle in a ratio “too good to be true,” Schmidt told me. “The bull is interested in the cow at the nadir of progesterone—about a four-week period—and especially at the few days around ovulation. The cow ovulates, and the progesterone starts to climb. The estrous cycle turns out to be about sixteen weeks long—the longest of any mammal by far.” The cow is willing to be bred for only a few days during her cycle: ovulation is a brief event, and the egg is viable for only about twelve hours. Schmidt tried mating three cows by cycle, placing each with a bull in a private room for several days of the magic period. All three became pregnant. “The pheromone was exactly, beautifully inverse to the progesterone,” he said. “You never see anything that clear, ever. There were some jokes about it, actually, because it did look too good to be true. But we had enough data so that we didn’t have to worry.”
    Schmidt is a careful man, never without a neat lab coat, and slow to offer a smile. But now he did. “At this time we were doing this work, the San Diego Zoo was using elephant urine to determine hormone levels,” he continued. “One of its endocrinologists presented a paper on this work at a conference, in the course of which he said, ‘Well, we all know that you can’t get blood samples from elephants.’ Now, that’s true of okapis and hippos and rhinos, and I think it’s great to develop urinary techniques for animals like that, because trying to get a weekly blood sample would be impossible. But elephants are domesticated animals as well as wild animals. The people in San Diego couldn’t get blood samples from elephants, so they assumed that nobody could. But a veterinarian can do much more with elephants than with other animals. Elephants are intelligent; they have an arm and a hand, and being able to manipulate the