Puberty and oestral cycle length in captive female jaguars Panthera onca

Abstract

Habitat loss and fragmentation have been leading jaguars to constant conflicts with humans, and as a result, jaguar populations have been declining over the last decades. Captive breeding is often a tool for species conservation, and it is not different for jaguars. However, success is far from optimal due to the lack of basic knowledge about species’ reproductive biology. In the present study, we assessed gonadal hormonal profiles of natural oestral cycles and puberty and compared our data to those of other wild felids. We collected faecal samples from two to seven times per week for 18 months from two adults and three pre-pubertal females. We defined baseline levels for progestins and oestrogens in order to estimate oestrous cycle length and age at puberty. We compared our data with 16 other species through generalized linear model, using weight and genus as two explanatory variables. Cycle length was 38.28 ± 2.52 days, ranging from 25 to 44 days, while sexual maturity was attained within 22 months. Due to our analysis of both hormonal and behavioural data, there is a variation between this research from other studies that employed only behavioural observations. Such difference may be caused by the absence of behavioural oestrous at the peri-pubertal period. When compared to wild felids of similar size, puberty and oestral cycle durations of the jaguar females fell within the same range. Our modelling showed that age at maturity was influenced mostly by size and only Leopardus partially explained the observed variation. Conversely, oestral cycle length did not differ among genera or size categories. Our study adds to the body literature in the reproductive endocrinology of wild felids, and because female gametes are more challenging to collect and preserve, a strong understanding on the female reproductive physiology is essential to assisted reproduction and wild population viability assessment.

Cycle length flexibility: is the duration of sexual receptivity associated with changes in social pressures?

“…At a comparative level, high variation in oestrous duration has been detected in animals (e.g. captive jaguars, with a mean duration of 10.42 and a range of 7 to 15 days [62]). Women, in contrast, show repeatable cycle lengths, even though there is some variation within [63] and across women [64], as well as extensive variation in average cycle length across human populations [65].…”

Cycle length flexibility: is the duration of sexual receptivity associated with changes in the social environment?

“…Our findings show that cycle phases are labile traits that females could potentially manipulate. At a comparative level, high variation in oestrous duration has been detected in animals (e.g., captive jaguars, with a mean duration of 10.42 and a range of 7 to 15 days [61]). Women, in contrast, show repeatable cycle lengths, even though there is some variation within [62] and across women [63], as well as extensive variation in average cycle length across human populations [64].…”

Cryptorchidism in free-living jaguar (Panthera onca): first case report

“…There are still many questions regarding the reproductive biology of jaguar, and the lack of literature is incompatible with its relevance in South and Central America. For example, ovulation forms ( Jorge-Neto et al, 2020 ), puberty and oestral cycle ( Viau et al, 2020 ) and sperm morphology, morphometry, ultrastructure and mitochondrial activity ( Silva et al, 2019 ) were only reported in the last three years, all in captive animals.…”