Drawing of black-footed ferret skullThe skulls of black-footed ferrets are being studied for changes due to the genetic bottleneck and the effects of captivity. For instance, captive raised animals are smaller than their wild or semi-wild kin. Animals raised in captivity initially showed higher instance of periodontal disease due to the high calorie soft diet the the species' tooth structure. The upper third premolar and the molar form a pocket that can trap soft food and lead to decay. The addition of more fiber to the diet has greatly ameliorated this situation.
Black-footed ferret skullMeasurements of black-footed ferret skulls before and after the bottleneck revealed that skull size was smaller after the bottleneck. It was determined that this effect was likely the result of captivity rather than genetics.
Black-footed ferret sperm bank cryopreserved in liquid nitrogen.Male black-footed ferrets are monitored for reproductive health. Males one year old or less may be sexually mature but lack sperm. Other common problems include abnormal sperm, often with very weak cell walls, and low motility. Electroejaculation is used to collect small beads of sperm both for analysis and artificial insemination. If not used immediately the sperm is kept frozen in liquid nitrogen. The sperm bank also serves as a natural history collection which can indicate changes in the species over time.
