Numbering about 1.5 million, wildebeests are the primary driver in the Serengeti ecosystem.
Zoologist and UBC professor emeritus Anthony R.E. Sinclair calls the Serengeti national park and ecosystem “one of the seven natural wonders of the world.” At 21, Sinclair, a New Zealander, who was raised in eastern Africa, looked out across the region’s plains and realized that he wanted to study the system for the rest of his life. He hoped to understand the forces that maintained such great numbers of animals of so many species through the centuries.
Sinclair will be speaking in Whitehorse and Haines Junction on Sunday and Monday. His talk, Understanding How Ecosystems Work: Comparing Serengeti with Yukon, will reveal the similarities and differences between the tropical plains system and a boreal system.
The well-travelled zoologist has also spent decades studying the wonders of the Yukon, especially at the facility at Kluane Lake. He will present his answers to a question that has intrigued him throughout his life: “How do these systems stabilize?”
“There has to be something that keeps them going,” says Sinclair. “Otherwise they’d all drift out of existence. There have to be processes that will keep things more or less as they are.” What do Yukon populations of such iconic creatures as caribou, moose and wolves have in common with wildebeests, lions and hyenas? What supports them? What threatens them?
What roles do food supply, predator numbers and disease play in the health of populations? How do such forces function in the Serengeti system that supports 28 species of herbivores and 10 of carnivores?
And how do they work in the boreal, which supports far fewer species?
Then, says Sinclair, his talk will turn to historical impacts. He will explore events, which took place in the Yukon or East Africa a century or two centuries ago that are even now affecting these massive ecosystems.
Sinclair has earned his perspective on ecosystems through a life of constant exploration. He has also witnessed a change in research technology and techniques over the same period. Aerial photography was just coming into its own in the mid-1960s when he was setting out on his professional path.
Imagine standing on the ground in the Serengeti, urges Sinclair. Imagine a mass of wildebeest stretching in every direction, “nonstop wildebeest as far as the eye can see – It’s one huge plain of 2,000 square kilometres. We fly back and forth over it for hours and hours.” Photographs are taken from about 1,000 feet (300 metres).
Sometimes, however, the scientists must count creatures in the savannah portion of the park where there are trees. Then they fly at about 300 feet (90 metres). Such methods are not as practical or safe in much of the spruce-covered and mountainous boreal, nor do they work well when trying to study stealthy carnivores. That’s when the camera trap becomes essential.
When you take an image of an animal, you’ve marked it and can later identify it. When this is done with a number of individual carnivores, then overall populations can be estimated.
GPS (Global Positioning System) and GIS (geographic information systems) along with new methods of statistical analysis have made the lot of a Serengeti zoologist somewhat easier than it was when Sinclair started out. “Prior to these new techniques we didn’t have very good estimates of numbers, but we’re getting better now.” And, of course, for smaller animals, such as rodents, both in tropical systems and in the boreal, live trapping answers yet more fundamental questions.
Food supply is, not surprisingly, a major driver in the health of ecosystems both in the Serengeti and in the boreal. Satellite imagery has become an essential tool for monitoring the tropical plains’ expansion and contraction of huge swaths of green. “Most of these animals feed on grass, therefore we have to spend a lot of time measuring grass.”
Monitoring food supply by aircraft or satellite is not an option in much of the boreal. The tree canopy masks changes on the ground. “You have to get on the ground to see what’s going on there,” says Sinclair.
The four-by-four vehicle is still an essential component of research in the world’s two most iconic ecosystems.
Despite the efforts of certain sectors to minimize such research, there’s much more to all this field work and analysis than esthetic considerations or monitoring recreational opportunities, says Sinclair. What happens in these major ecosystems is “vitally important for human society and our future.”
Sinclair presents a favourite analogy: Suppose you have found an individual young animal in distress. You would like to save and raise it, but unless you know what to feed it, your intentions count for nothing and it will die. “If you want to keep your ecosystems going, and I think we better … science is not there simply as an academic exercise.” With a burgeoning population of humans, it is more vital now than ever to understand the mechanisms of systems like the Serengeti and central Yukon.
“Scientists sometimes get told to butt out,” says Sinclair. “But it’s not like we’re trying to say, ‘Stop industry from doing their thing.’” We’re just saying, ‘Don’t do it in 100 per cent of the area.’ We need to have reference points or baselines to tell us what is going on in our modified environment.
“I’m not confrontational. I like to say, ‘I know where you’re coming from,’ but we need to work on these things together as our insurance policy.”
For more on all these and other aspects of Sinclair’s essential, exciting life’s work, read Serengeti Story: Life and Science in the World’s Greatest Wildlife Region (Oxford University Press) and attend his talk
March 30 at 7:30 p.m. at the Beringia Centre in Whitehorse or March 31 at 7:30 p.m. at the Saint Elias Convention Centre in Haines Junction.
This column is co-ordinated by the Yukon Research Centre at Yukon College with major financial support from Environment Yukon and Yukon College. The articles are archived at http://www.yukoncollege.yk.ca/research/publications/newsletters_articles