It has been more than two decades since the civil war in Mozambique destroyed much of the large animal population of the country’s Gorongosa National Park.
“Gorongosa was one of the most phenomenal parks,” said Ryan Long, a University of Idaho researcher. “It rivaled the Serengeti. Unfortunately, during the Civil War, more than 95 percent of the animals were killed to feed the soldiers and fund the war.”
Since then, the nearly animal-devoid park has served as a rare case study in large animal reintroduction for researchers, including Long.
Long has worked in the area over the past three years and in August, a team of researchers led by Long, received a $1.25 million grant from the National Science Foundation, $700,000 of which is allocated to UI, to study the adaptability of animals returning to the park.
Long’s team includes Princeton researchers Rob Pringle and Corina Tarnita.
The grant funds a research project for Long and his team to study how different sizes of closely related species of antelope react differently to changes in the available resources. It also funds an integrated field course that will send about five undergraduates from UI and Princeton and about five undergraduates from Universidade Eduardo Mondlane in Mozambique to Gorongosa Park.
“It will be a really cool international experience in the process,” Long said.
UI’s share will fund one Ph.D. student as well as equipment, including all of the GPS collars for the antelope.
Long’s research focuses on three species of the genus tragelaphus spiralhorned antelope. Long said the species have very similar foraging patterns and rely on the same kinds of woody plants, but do not overlap in body size, with Kudu being larger than Nyala, which are larger than Bushbuck — all three different species of spiral-horned antelope.
“We get to see effects of body size on behavior without all the confounding behaviors you would find when studying vastly different species,” Long said.
Long said body size can have a variety of effects on how adaptable a species is.
Long said animals like antelope, small-bodied species require higher-quality forage. “Because they’re small, food moves through their system fairly rapidly,” Long said. “They can’t extract nutrients as efficiently. A larger animal holds onto its food longer and so digests it more fully and efficiently.”
He said this can be seen in the size of the range different-sized animals inhabit.
“If you have a drought year and the availability of good food goes down, small animals will be constrained,” Long said. “But large bodied animals will be fine.”
Long said body size affects animals in other ways too. He said larger-bodied species have the ability to move longer distances in situations where resources become scarce, storing more energy and having longer legs.
“A large animal like an elephant can migrate hundreds of miles if it needs to,” Long said. “But a small animal like a duiker is not capable of that kind of movement. If a duiker runs out of resources in its area, it can only move so far.”
Long said variation in body size is a universal trait, applying to species such as mule deer, elk and moose. “Those results will apply just as well to a lot of the species we hold near and dear here at home,” Long said. Long said thanks in part to the Carr Foundation, established by Idaho businessman Greg Carr, park populations are improving, particularly among herbivores, but that things have changed.
“As they’ve recolonized, the community composition is very different,” Long said. “Prior to the war it was dominated by buffalo and zebra. Those bulk grazers have been slow to recover. Mid-sized species like water buck and impala have done really well.”
However, he said predators have been particularly slow to recover. He said the park used to be home to lions, leopards, cheetahs, hyenas and African wild dogs.
Long said the last two years of the project will be an experiment. He said once the team has identified a significant overlap in the range of all three species, the team will remove some of the available food and observe how the different species react.
“From a purely scientific perspective, it’s like a massive natural experiment to see what happens to an ecosystem when all the animals are suddenly removed from it,” Long said. “There’s really nowhere else in the world we can see something like this at this scale.”
Nishant Mohan can be reached at [email protected] or on Twitter @NishantRMohan