Dynamic mother–calf vocal recognition in Père David’s deer

Abstract In mammals, varying social and environmental factors shape species-specific mother-young vocal recognition. Traditional theory holds that antipredation strategies (hiding versus following) drive ungulate vocal recognition patterns: followers often show mutual recognition, while hiders typically show unidirectional offspring to mother recognition. However, when the offspring of hider species join the social group, they still need to maintain efficient mother–offspring interactions and face selective pressures similar to those of follower species. This critical stage remains poorly studied. We examined mother-young vocal recognition changes between hiding and social group phases in Père David’s deer (a classic hider). Results show that during the hiding phase, offspring recognized their mothers, but mothers only recognized their own calves in the subsequent social group phase. Hiding phase mothers responded strongly to all calf calls. Despite mothers the ability to recognize their own offspring by the social group phase, their response to calf calls declined significantly. This decline may be because, once calves are in the social group, mothers can obtain more real-time information about their offspring through additional sensory modalities (such as vision and spatial memory), thereby reducing their reliance on vocal signals alone. This work demonstrates stage-specific recognition development in Père David’s deer, challenges the traditional hider-follower framework, and proposes a novel early-stage maternal investment trade-off strategy that awaits testing, offering fresh insight into mammalian maternal behavior and life-history evolution.