Asynchronous Parturition in Bison: Implications for the Hider-Follower Dichotomy

Birth dates were examined for bison (Bison bison) at Wind Cave National Park, South Dakota, over a 3-year period (1982–1984) to determine the degree of synchrony. Duration and timing of birth seasons varied among years. Parturition was substantially less synchronized than previously reported for bison. Length of birth season did not fit the pattern typical of ungulates exhibiting a follower strategy of mother-young spatial relations, being longer than expected. These results are consistent with species-specific patterns of mother-young spatial relations, and provide further evidence that bison differ from typical follower species. Thus, these findings reflect the limitations of the hider-follower dichotomy.