Roundup

UI scientist maps gorilla habitat in Rwanda

This past summer UI scientist Larry Lass struggled up the steep slopes of Karisoke Mountain, one of five volcanoes in Rwanda's Virunga Conservation Area, in search of plants crucial to the survival of the last of the planet's mountain gorillas.

The expedition, sponsored by the National Geographic Society and the Dian Fossey Gorilla Fund International, featured the threat of jungle warfare, biting weeds, humidity, and the occasional troop of mountain gorillas strolling by close enough to make eye contact.

"I knew what was going on politically, and I felt secure strictly because the military escort was there," said Lass. Rwanda is at war with the Congo, its neighbor to the west.

© Dian Fossey Gorilla Fund International.

Top: Mountain gorillas on the volcano amid bracken fern and stinging nettles. Bottom: A new farming settlement at the base of a Virunga volcano (Photo by Larry Lass). Left: Larry Lass in Rwanda.

Chaperoned by a dozen Rwandan soldiers toting automatic weapons, Lass used a global positioning system (GPS) to record the precise locations of representatives of each kind of plant important to the gorillas. Stinging nettles, one of several key species he was looking for, left their mark on Lass. "They have a stronger bite than their American counterpart, with a sting that lasts about 20 minutes," Lass said. The nettles provide protection from poachers and forage for the gorillas, who roll the spikey weeds into balls and pop them in their mouths like party platter entrees.

Lass is a vital link in a sophisticated chain of plant identification technology that begins with the airborne Probe 1 hyperspectral sensor, developed by NASA in the early '80s and adapted for commercial use in 1997 by McCall, Idaho-based Earth Search Sciences Inc. (ESSI).

Attached to a plane flying over the Virunga volcanoes at 8,000 feet, the Probe 1 sensor split the visible and infrared light reflected off the jungle's surface into 128 bands; Landsat and other aerial and satellite sensors analyze four to seven bands. The Probe 1's broadened spectrum allows remote sensing of plant species with unprecedented accuracy, said Larry Vance, ESSI chairman.

Back in his UI office, Lass is comparing the hyperspectral data with the positioning information he collected on the ground, ultimately translating millions of color pixels on his computer screen into the names of the plants they represent.

"We will have, for the first time, a very detailed picture of the distribution and abundance of the most important plant foods for the gorillas," said Dieter Steklis, chief scientist for the Fossey fund. "That will allow us to estimate fairly precisely the amount of usable gorilla habitat in the Virunga."

"It's nice to see Larry's expertise get recognized," said UI weed scientist Donn Thill. "It's nice to see the university's expertise is seen as world class. There are all kinds of applications for this technology."

For example, the technology could allow farmers to locate pockets of weeds so that they could treat just the infested areas, rather than the entire crop.

The National Geographic Society planned to air a television documentary of the expedition in December.
-- Donna Emert