The binturong is a medium size carnivore belonging to the Viverrid family that lives in dense forests of South-East Asia. In addition to the protection of this vulnerable species in its natural habitat (in situ), conservation breeding efforts (ex situ) aim at maintaining a good genetic diversity while increasing the number of individuals to reinforce wild populations. Both approaches require a solid understanding of binturong's basic biology. However, there is still a lack of precise information about reproduction. The objective of this brief research report was to analyze testicular sizes and semen characteristics at different times of the year to better understand the reproductive physiology and inform future conservation efforts. A secondary objective was to describe sperm cryotolerance for the first time in that species. Examinations of testes and semen collections were conducted on two adult males. While testicular measurements were relatively constant across multiple examinations, semen characteristics (volume, viability, sperm concentrations, sperm motility) varied between samples. However, incidence of sperm morphological abnormalities was consistently high. Sperm cryotolerance appeared to be poor but further studies are warranted. The present dataset will be useful for future research on binturong reproduction and for the development of assisted reproductive techniques and biobanking of germplasms in that species.
A better understanding of semen characteristics and resilience to freezing temperatures is necessary before developing assisted reproductive techniques and systematic biobanking for the Sunda clouded leopard. The objective of this study was to evaluate for the first time the semen and sperm quality (in fresh and frozen samples) of two captive Sunda clouded leopards in Malaysia. A total of 17 examinations of the reproductive tract (using ultrasonography) and electro-ejaculations were performed on the two leopards over a 2-year period. Samples obtained from Leopard 1 (8 years old) varied in terms of volume (402 ± 92 µL), pH (7.9 ± 0.9), sperm motility (54.5 ± 24.2%), sperm concentration (122.4 ± 84.7 × 106 sperm/mL), normal morphology (23.9 ± 12.3%), and viability (55.2 ± 18.2%). Midpiece defects represented the most common structural abnormality followed by abnormal tail and head defects. Samples from Leopard 2 (11 year old with abnormal testicular tissue) were of lesser quality. Two frozen semen samples from Leopard 1 were thawed and examined for acrosome integrity. Post-thawed samples contained <10% of motile spermatozoa but almost 50% of abnormal acrosomes. The present results emphasized the high incidence of structurally-abnormal spermatozoa, similar to the mainland clouded leopard. Post-thaw evaluations showed that the few surviving spermatozoa could potentially be used for in vitro fertilization or sperm injection. However, more individuals must be studied to validate those first findings that are exciting but still preliminary.