Reproductive biology of the 38 extant felid species: a review

Knowledge of reproductive biology is crucial to improving in situ and ex situ breeding programmes for felids. We reviewed the available literature (223 publications) on the reproductive biology of all 38 felid species. We found that 78% of the publications (173) were focused on either or both the oestrous cycles (84) or ejaculate traits (92) of felids. Literature was biased towards the domestic cat Felis catus (31), the cheetah Acinonyx jubatus (27), and the panthera lineage (66). There was a paucity of literature on the caracal lineage (7), the bay cat lineage (3), members of the domestic cat lineage other than the domestic cat (11), and several species of the ocelot lineage. The mean duration of oestrus varies little between the different lineages and species (mean 5.2 days, range 1-10 days, n(E) = 2265). However, the duration of interoestrus varies greatly in most species (e.g. 1-118 days in the domestic cat). Gestation length also varies significantly between species, but is similar within each lineage and related to adult body size. Non-pregnant luteal phases appear to persist for half the duration of pregnant luteal phases (48%, 21-71 days, n(E) = 256; c.f. previous reports of one-third the duration of pregnant luteal phases). Sperm motility (sperm motility index), sperm viability, and acrosome intactness are high in the fresh ejaculates of most felid species [69% (26-90%, n(E) = 2104), 69% (49-87%, n(E) = 443), and 84% (21-100%, n(E) = 1763), respectively]. Teratospermia is highly prevalent within Felidae, but is particularly problematic for the puma and lynx lineages [ejaculates with 76% (63-94%) and 79% (63-98%) abnormal sperm, respectively]. Teratospermia appears to be linked to low genetic diversity. The maintenance and enhancement of genetic diversity through the use of assisted reproductive technologies should be a long-term goal for felid conservation management. A short-term management goal should be to improve the success of assisted reproductive technologies in felids by minimising captivity-related stress, which can adversely affect fertility and ovarian activity.