Name ID 1820
Page Number: 3
Extract Date: July 2004
Unravelling the mighty rut
When Estes first saw the rut in 1964, he developed his theory that the 'big hum' brings on an epidemic of oestrus. "The calling of the bulls was so conspicuous," he says, "there had to be a reason." Forty years later, Estes is working with Smithsonian's National Zoological Park to test his theory.
On a reserve on the western fringe of the Serengeti, three small herds of Wildebeest females have been isolated in 10-hectare enclosures. One group was exposed to three weeks of recorded rutting calls. Another group heard the same calls, with the added stimulation of a live, but quiet, bull. The control group heard no bull, saw no bull, smelled no bull.
Allison Moss is the PhD student running the Smithsonian's project. "There are segments of that CD that the cows really like, the part where they can hear just one male," she notes. "There are a couple of females who always get moony when they hear that."
To confirm this anecdotal evidence, researchers in Smithsonian Institution's Conservation and Research Center in Virginia are analysing hormone residues in faecal samples to detect when cows go into oestrus. The team collect samples from all the cows' droppings. Inside a makeshift lab-in-a-tent, Moss freezes, thaws, measures, boils, centrifuges and dissolves dung in preparation for a flight to Virginia, where hormone levels are measured using radioactive isotopes, a technique pioneered by Steven Monfort. It's not as simple as looking for a blue stripe on an ovulation predictor kit but safer than sticking a needle into a Wildebeest.
Moss is frequently up in the middle of the night coping with leopards and other project crises. She thinks nothing of spending a 12-hour day in an incredibly hot, fly-infested canvas lab. Still, she marvels at Estes's youthful enthusiasm. "The man is 76-years old, he's been doing this for 40 years, and he still wakes me up at 5.30am to look at Wildebeest with him when we're out in the field. Not because he wants the fame or he wants to publish more, he's just constantly fascinated by them."
Like the endless journey of Wildebeest, Estes's quest to understand the workings of the wild never stops.