Telomeres are the repeating nucleotide sequences at the ends of chromosomes that protect them from degradation and fusion. They shorten with each cell division, and their length is associated with aging and age-related diseases. In humans, shorter telomeres have been linked to a higher risk of death from all causes, including cardiovascular disease, cancer, and respiratory disease.

However, most studies on telomere length have been conducted in humans and other laboratory animals. It is not known whether telomere length is also a predictor of lifespan in wild animals.

To answer this question, researchers from the University of Montana studied a population of bighorn sheep in the Rocky Mountains. They measured the telomere length of white blood cells from 147 bighorn sheep and tracked their survival over a period of 11 years.

The results showed that bighorn sheep with shorter telomeres had a higher risk of death from all causes. The researchers also found that telomere length was a better predictor of lifespan than age or sex.

This study is the first to show that telomere length predicts lifespan in a wild animal. It suggests that telomere length may be a universal marker of aging and age-related diseases across species.

The researchers say that their findings could have implications for the management of wildlife populations. For example, they could be used to identify animals that are at a higher risk of death and to develop interventions to extend their lifespan.

The study was published in the journal "Ecology Letters".