Oscar the cat seems to have an uncanny knack for predicting when nursing home patients are going to die, by curling up next to them during their final hours. His accuracy, observed in 25 cases, has led the staff to call family members once he has chosen someone. It usually means they have less than four hours to live.

"He doesn't make too many mistakes. He seems to understand when patients are about to die," said Dr. David Dosa in an interview. He describes the phenomenon in a poignant essay in Thursday's issue of the New England Journal of Medicine.

"Many family members take some solace from it. They appreciate the companionship that the cat provides for their dying loved one," said Dosa, a geriatrician and assistant professor of medicine at Brown University.