Maternal and allomaternal care in horses

Abstract

Horses (Equus caballus) live in stable groups and are known as a species whose strong social bonds between unrelated female group members increase both foal birth and survival rates. In mammals, the origin of social bonds lies in the mother-infant interaction. Therefore, it is important to study the mother-infant relationship of horses to understand the developmental basis of social bond formation. In this paper, we describe the pregnancy, parturition, maternal and allomaternal care, of horses. We also describe the pregnancy, parturition, maternal and allomaternal care, of zebras (E. quagga, E. zebra, E. grevyi), a close relative of the equine species. Then, we summarize the characteristics of horses' maternal and allomaternal care by comparing them with those of zebras from the perspectives of domestication, habitat, and group stability. Finally, we propose some possible future studies to explore equine or follower-type ungulates' maternal and allomaternal care by referring to the importance of comparing maternal care and allomaternal care of follower-type horses with those of the other follower-type and hider-type ungulates.