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The man lying on top of his car, sleeping comfortably
while thousands of wildebeest mill around, is Richard
Estes. He has become one of the world's authorities
on the wildebeest of Tanzania, East Africa by living
among them for years, studying their feeding habits,
their sex lives, newborns and their mothers. The cycle
of this antelope's 365-day-a-year migration pattern
fascinates him, especially the annual mating ritual
known as the Serengeti wildebeest rut.
Estes tries - and sometimes fails - to arrive
in Tanzania from his home in New Hampshire during the
three weeks when summer migration coincides with the
rut. For those three weeks, usually from around mid-June
to early July, 250,000 males compete to service at least
750,000 females.
"The noise made by the bulls is probably the
most amazing thing," Estes said of the rut. "There I
am, sleeping on top of my car, with a hundred-thousand
wildebeest surrounding me, mostly females and calves.
There may be as many as 10,000 bulls grunting like giant
bullfrogs, combining their voices into what I call The
Big Hum. The noise resonates like the sound of surf
crashing against rocks.
"You don't actually see them mating all that
often," said Estes, "but the bulls are running around,
butting their heads together and expending enormous
amounts of energy to round up females and keep them
together. I've seen bulls so intent on rounding up and
defending a herd that they completely overlook the presence
of estrus females. That defeats the whole point of the
exercise."
So there they stand, pawing the ground, soiling
their horns in manure, rolling onto their backs to advertise
their territories. These territorial males breast the
tide of the migration as thousands of wildebeest of
both sexes and all ages move along the migration route.
Moving in a distinctive, rocking canter, with
heads raised and voices uttering deep grunts, the territorial
bulls round up as many cows as they can and drive off
the accompanying bachelor males. Meanwhile, they try
to keep the females on postage-stamp plots, often much
smaller than an acre, until they get lucky and a cow
in heat lands on their territory. "It's
a lot of work," said Estes. "The return on a bull's
investment, in reproductive terms, is very low."
The rut takes place at the end of the long rainy
season, when the wildebeest reach the peak of their
fitness. Then they move to the woodlands and, when the
rains begin again in November, back to the short-grass
plains. Eight months after the rut, sometime between
the end of January and the beginning of March, the females
will calve. The three-week calving season, during which
ninety percent of wildebeest babies are born, creates
an unforgettable spectacle on the Serengeti plains.
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