Nowhere in a natural ecosystem is the task of carcass creation and disposal more out in the open to human eyes than in the Serengeti region of East Africa, an intact ecosystem with a virtually Ice Age fauna. Six species of vultures live there. Some 12 million kilograms (the weight of about 200,000 men) of soft tissue (meat) per year is available for vultures in the Serengeti, and the birds find almost all carcasses, even those hidden in thick brush.
The specific scenarios of undertakers of large carcasses in Africa vary, but the pattern is like the following partial sequence I observed in 1995 at the carcass of an adult reticulated giraffe, Giraffa camelopardalis, the largest ruminant and also the tallest land animal. Bulls may be 19 feet tall and weigh more than 4,000 pounds. There is a lot of meat on the platter for scavengers when one of these animals drops.
The giraffe I observed had lived in the acacia bush in South Africa's Kruger National Park. It had probably been down only one day when I found it lying within a hundred meters of a sandy road in semidesert acacia gallery forest. It was late morning, and some of the show was already over, so what I write here is largely extrapolation and speculation.
I suspect that the giraffe was old or sick, because a healthy one is not normally taken down by lions, several of whom were nearby. These cats, weighing 250 to 300 pounds, can ingest 35 pounds each in a night of feasting. In the heat of the day, they were lying in the shade of an acacia tree.
The lions had probably killed the giraffe in the night, and their commotion attracted hyenas and jackals. After satisfying their appetites, the lions yielded to the insistent harassment of the hyenas, who, when they in turn were sated, yielded to jackals.
Soon after the morning sun had warmed the plain and the warm air had risen, vultures flew from their perches in some communal roosting place. They spiraled ever higher, their sharp eyes scouring the plain. The first vultures to see the carcass and the lions, hyenas, and jackals scattered about stopped soaring and started their gliding descent. Other birds in the distance, also soaring, watching not just ground but also sky, saw the first vultures begin their descent and did the same. And so on, one vulture informed by the next more distant one, until a horde of hundreds was barreling in from all directions, perhaps from over a hundred miles away. Some of the vultures were already done feeding when I arrived. They were perched in the nearby trees, and some were flapping off again.
In a day or so not much would be left of the carcass. Any meat remaining would be flyblown, with writhing masses of maggots. After the large meat eaters leave, the remains are reduced to dry bones and hide and fur, and then beetles fly in, and they and their larvae finish up the scraps.
Meanwhile, the lions, hyenas, and jackals process the giraffe's remains into scat, and dung beetles process even that last remnant of the giraffe, including whatever it had eaten during its lifetime. The beetles fashion animal dung into round balls, which they roll for long distances and then bury, to serve as food for their offspring. After the next rains, when the earth softens and fresh green grass and flowers spring up anew, the young beetles emerge at night and fly off, skimming over the veldt, guided by the scent of antelope, elephant, rhino, hyena, or lion excrement, in search of further feasts. As they fly, many are caught and eaten by bats at night and by gorgeous birds (including fishers, drongos, starlings, and rollers) during the day. One giraffe died, but a dozen lions, hyenas, and jackals and perhaps hundreds of vultures were fed. Thousands of dung beetles had a feast, and the plains would grow more grass.