Some wild animals who grow up in a “poor or unpredictable” environment might have longer lives, according to a study released on Monday by the University of Exeter. By using 14 years of data on wild banded mongooses in Uganda, a team led by researchers from the University of Exeter analysed how animals survive in a wild environment. They found that male mongooses that experienced highly variable ecological conditions during development lived longer and had greater lifetime fitness, while those that experienced poor early-life conditions lived longer but at a cost of reduced fertility. Variable conditions were defined as those with large fluctuations between wet and dry periods. “It’s not clear why variable early-life conditions were the best for male mongooses in terms of longevity and reproduction,” said Harry Marshall from the University of Exeter, one of the authors of the study. It might be that male mongooses that experience different challenges in their first year are better prepared for those challenges later on, explained Marshall. Meanwhile, it appeared that early life conditions have no impact on females’ longevity or reproductive success, according to the study. “We know that female mongoose survival is more sensitive to ecological conditions later in life, perhaps due to the greater demands pregnancy brings. This may hide any effects of conditions experienced during their first year,” explained Marshall. Deciphering why these effects evolved through studies on wild animals have implications for human health, said Michael Cant from the University of Exeter, who is another author of the study. The study has been published in the journal Ecology & Evolution.