Interactions between adult male koalas and dependent joeys in a high-density population

Abstract

During a study of interactions among koalas, we observed interactions between adult males and dependent joeys. Most were passive in nature, suggesting that interactions with adult males are not a major threat to joey survival. However, one male–joey interaction resulted in a joey falling approximately 7 m to the ground, an incident that may have resulted in the death of the joey had we not intervened. We suggest that there is potential for infant death to occur under the generalised aggression hypothesis for koalas, although further observations are needed.