Opossums cleaning our cities: consumption of rodent carcasses in an urban reserve

Abstract

Rodent carcasses are a source of food and a biological hazard that can commonly be found in natural and anthropic ecosystems. Therefore, this article aims to determine which organisms consume those carcasses in an urban reserve. For this, 53 rodent carcasses were placed in front of camera traps to record their consumers. The final destiny of 41 carcasses is known: 76 % were consumed by opossums (Didelphis virginiana) and 24 % by ringtails (Bassariscus astutus). Flies and ants attempted to take advantage of the carcasses but in all cases ended up losing the competition to mammals. Opossums are the most efficient carrion consumers, as they exhibit learning as to where the carcasses are located and are able to consume old carcasses (up to 10 days old). This suggests that mid-size mammals, especially opossums, are providing an important ecological and health service for both natural ecosystems and human populations by removing rodent carcasses that otherwise could become sources of infection.