Running Hot and Cold
U of G researchers study how elephants, hippos, rhinos and other zoo animals control their internal thermostat
BY ANDREW VOWLES
|Esther Finegan and her students are pioneering thermoregulation studies in zoos and animal parks. Photo by Martin Schwalbe|
Does the zebra wear its white stripes on the black or its black stripes on the white? Alter that age-old puzzle slightly and you come close to the research interest of Esther Finegan: Did the zebra grow black stripes to warm up or white stripes to cool down?
As an adjunct graduate faculty member in the Department of Animal and Poultry Science (APS), Finegan studies thermoregulation, or how animals keep a comfortable body temperature. Not just any animals: she’s interested in so-called “captive exotics” — zoo animals whose climate-control mechanisms remain mostly unstudied.
Elephants, hippos, rhinos, giraffes: how do these big beasts control their internal thermostat, and how can zookeepers and landscape architects better design the animals’ surroundings to keep them happy and healthy?
She and her students are now pioneering thermoregulation studies in zoos and animal parks, notably the Toronto Zoo and a zoo in the southern United States.
Large land mammals face a thermo-challenge, says Finegan, a two-time Guelph graduate. The larger you are, the more internal mass you have compared with the surface area of your skin. For much the same reason that a jumbo-sized potato takes longer to cool than its mini-tuber cousin, an elephant ridding itself of excess heat faces a bigger task than a cow.
“By the time you’re a mouse, you’re almost all surface,” she says.
It was a former student — Matthew Schotsman — whose work tipped off keepers about why their African elephants were agitated in the morning during hot spells. Not only were the animals getting hot under the collar during long days spent outside, but they were also unable to give off excess heat when their keepers brought them indoors at night.
That kind of information can help in improving housing and animal management, says Jen Gailis, a master’s student with Finegan. Hoping to record that day-heating and night-cooling phenomenon, called “adaptive heterothermy,” she will spend a month observing Asian elephants this spring.
During 30-hour stints shared with Finegan and another student, she will film the animals with a thermal-imaging camera to see how and when they store and radiate heat. The researchers will run the camera every 15 minutes to catch all the action — even filming the elephants urinating to help measure changes in core body temperature.
They’ll also record meteorological conditions and jot down the elephants’ activity practically minute to minute. Among other things, they’ll watch how the animals use shade, even down to which parts of their body are shaded.
African elephants use their large leaf-like ears as heat dispensers. Another of Finegan’s grad students, Brandon LaForest, found that their smaller — and smaller-eared — Asian cousins use their trunks to radiate heat at night. No one is sure why, says Gailis, who hopes to learn more by observing just how elephants position themselves in shade and sun.
Other graduate and undergraduate students are looking at rhinos (Aly Van Slack), hippos (Katherine Stevenson) and giraffes (Denise Lukacs).
Dan Ingratta, a fifth-year student in animal biology, is studying black-and-white animals, specifically zebras and Malayan tapirs. He plans to use the imaging camera to compare surface temperatures on different parts of the animals’ bodies.
“The black part of a zebra standing in the sun can be 10 degrees hotter on average than the white,” says Finegan. But, she adds, “we don’t know how much of a zebra is black or white — and does it matter?”
Taking a different tack, undergraduate Victoria Pyett is studying how fur insulates lions and tigers. (Thermal comfort in big cats was the topic of a thesis by recent MLA graduate Tory Young, who was co-supervised by Finegan. See “Lions and Tigers in Zoos, Oh My!” in the Feb. 10 issue of At Guelph.)
Other campus researchers have looked at thermoregulation in domestic animals. For example, APS professor Tina Widowski has studied housing and management practices for livestock, including shade- seeking behaviour in cattle and thermal stressors in pigs during transport. But fewer scientists study the topic in zoo creatures, says Finegan.
To begin with, it wasn’t thermo-regulation that drew her but nutrition in farm animals. She studied sheep nutrition for her master’s degree with APS professor Jock Buchanan-Smith and began her doctorate with him. After he retired, she completed her PhD with Prof. Jim Atkinson.
She developed a mathematical computer model of how herds of grazing beef cattle maintain heat outdoors. That work combined nutrition and thermoregulation.
“I’m interested in the whole animal,” says Finegan, who still works with Atkinson and has taught his wildlife nutrition course.
Her research with the Toronto Zoo started about six years ago with devising diets for giraffes and moose. She widened her studies to Florida last year.
Finegan grew up in England and studied zoology and botany at the University of London. Her first work in Canada involved thermoregulation of a sort — her own. Along with other researchers from Laurentian University, she spent two summers on Devon Island in Canada’s Arctic. She studied lichens as part of the International Biological Program, a large-scale ecosystem project in the 1960s and ’70s.
Later she studied statistics and worked in stats and computing in Toronto before returning to school at Guelph.
Someday she’d like to take her studies beyond the zoo and park gates to, say, the African savannah. But she says it’s important to work with captive animals to establish baselines in this young field. Besides, she enjoys working not just with the zoo animals but also with the visitors.
“Most people are really interested but have very little information on the animals,” says Finegan, who sees herself partly as a U of G ambassador during her fieldwork. “That really is a bonus to me.”