The summary does not say that healing doesn't occur for females, but rather that the variance of healing is not effected in similar ways as for males. Males ad

The summary does not say that healing doesn't occur for females, but rather that the variance of healing is not effected in similar ways as for males. Males adjust their healing (or to be specific, the increased expression of anabolic genes) based on the injury. Low to medium injuries resulted in increase healing, while larger force decreased healing. This adaptation to injury allows for greater healing in average, while female rabbits maintain the same relative lower rate of healing regardless of injury. Since we are talking about rabbits it is important to look at sex difference in that species. Males fight each other with only a few being able to successfully reproduce. Female rabbits do not. Males that successfully reproduce will need to repeatably heal themselves from minor to medium injuries. Thus we could explain the variance as being a natural results of that process.