Annelisa M. Kilbourn

Annelisa M. Kilbourn, a British veterinarian and wildlife expert, who established that gorillas can die of the deadly Ebola virus, was killed Saturday when the light plane she was flying in crashed in the Lope Nature Preserve in the Central African nation of Gabon. She was 35.

Working for the Wildlife Conservation Society, which announced her death from its headquarters at the Bronx Zoo, Miss Kilbourn was investigating last year ' s Ebola outbreak in that country and its relationship to the indigenous gorilla population.

Earlier this year, Miss Kilbourn established for the first time that Ebola is a serious threat to wild gorillas as well as to humans when she found dead gorillas in the jungle and found that the disease had killed them, the society said.

Her findings had important implications for the preservation of Africa ' s primates as well as for the spread of the disease among humans. Scientists had already noted that an earlier outbreak of Ebola in the same area in 1996 had led to a sharp decline in the gorilla population and now they knew why.

They also now knew that Ebola, as well as predatory hunting by humans, is one of the reasons gorillas are fast disappearing from Africa ' s forests.

Miss Kilbourn ' s discovery also made it increasingly important to protect the major concentration of gorillas in the nearby Odzala National Park by controlling access to them by humans and animals that might be carrying the virus. The concentration is believed to be the largest left in the world; the park is about 100 kilometers away over the border in Congo. Before her death Miss Kilbourn had herself been in charge of protecting the health of these animals.

Finally, the knowledge that gorillas as well as chimpanzees and monkeys are vulnerable to Ebola implied that one of the ways the disease spreads among humans is through the hunting and eating of infected primates.

Ebola is a poorly understood tropical disease that erupts from time to time in various parts of Africa and for which there is no cure. The disease can cause internal organs to liquefy; about 70 percent of its human victims die.

Annelisa Marcelle Kilbourn was born June 27, 1967, in Zurich. A British citizen, she received bachelor ' s degrees in ecology and in environmental biology at the University of Connecticut in 1990 and graduated in veterinary medicine from Tufts University in 1996.

From 1996 to 1998 Miss Kilbourn worked in Malaysia with a Wildlife Health Fellowship from the Wildlife Conservation Society, helping protect free-ranging orangutans and elephants.

Upon completion of this project she took a two-year position at the Lincoln Park Zoo and Shedd Aquarium in Chicago. Later she accepted a permanent position at the Shedd but also worked with the SOS Rhino project to save Borneo ' s rhinos, and with the Wildlife Conservation Society in Central Africa.

Miss Kilbourn is survived by her parents, Hans and Barry Kilbourn of Norwalk, Conn., and by her sister, Kirsten Kilbourn of South Windsor, Conn.