• 117 Cryopreservation of snake semen: Are we frozen in time?

      Zacariotti, R.; Guimarães, M.; Jensen, Thomas; Durrant, Barbara S. (2011)
      The increasing number of endangered snake species, isolation of small fragmented populations with associated inbreeding and mating or conception problems in captivity underscore the need to develop assisted reproductive techniques such as semen cryopreservation and artificial insemination to enhance conservation efforts. However, no efficient protocols for semen evaluation, cooling, or freezing are described in the 4 known publications on snake semen cryopreservation. In this initial study, semen was collected noninvasively from 4 live adult red diamond rattlesnakes (Crotalus ruber) by ventral massage....
    • Cross-cultural consensus for waist–hip ratio and women's attractiveness

      Singh, Devendra; Dixson, B. J.; Jessop, T. S.; Morgan, Bethan J.; Dixson, Alan F.; (2010)
      In women of reproductive age, a gynoid body fat distribution as measured by the size of waist–hip ratio (WHR) is a reliable indicator of their sex hormone profile, greater success in pregnancy and less risk for major diseases. According to evolutionary mate selection theory, such indicators of health and fertility should be judged as attractive….
    • Estrogenicity of captive southern white rhinoceros diets and their association with fertility

      Tubbs, Christopher W.; Moley, Laura A.; Ivy, Jamie A.; Metrione, Lara C.; LaClaire, Sydney; Felton, Rachel G.; Durrant, Barbara S.; Milnes, Matthew R. (2016)
      …In this study, we investigate the role of dietary phytoestrogens in this reproductive phenomenon by characterizing activation of southern white rhinoceros (SWR) estrogen receptors (ESRs) 1 and 2 by diet items from nine North American institutions and comparing female SWR fertility to total diet estrogenicity. Of the diet items tested, alfalfa hay and soy and alfalfa-based commercial pellets were found to be the most potent activators of SWR ESRs.…
    • Female giant panda (Ailuropoda melanoleuca) chirps advertise the caller's fertile phase

      Charlton, Benjamin D.; Keating, J. L.; Rengui, L.; Huang, Y.; Swaisgood, Ronald R.; (2010)
      Although female mammal vocal behaviour is known to advertise fertility, to date, no non-human mammal study has shown that the acoustic structure of female calls varies significantly around their fertile period. Here, we used a combination of hormone measurements and acoustic analyses to determine whether female giant panda chirps have the potential to signal the caller's precise oestrous stage (fertile versus pre-fertile)….
    • Gut microbiota and phytoestrogen-associated infertility in southern white rhinoceros

      Williams, Candace L.; Ybarra, Alexis R.; Meredith, Ashley N.; Durrant, Barbara S.; Tubbs, Christopher W. (2019)
      With recent poaching of southern white rhinoceros (SWR [Ceratotherium simum simum]) reaching record levels, the need for a robust assurance population is urgent. However, the global captive SWR population is not currently self-sustaining due to the reproductive failure of captive-born females. Dietary phytoestrogens have been proposed to play a role in this phenomenon, and recent work has demonstrated a negative relationship between diet estrogenicity and fertility of captive-born female SWR. To further examine this relationship, we compared gut microbial communities, fecal phytoestrogens, and fertility of SWR to those of another rhinoceros species—the greater one-horned rhinoceros (GOHR [Rhinoceros unicornis]), which consumes a similar diet but exhibits high levels of fertility in captivity. Using 16S rRNA amplicon sequencing and mass spectrometry, we identified a species-specific fecal microbiota and three dominant fecal phytoestrogen profiles. These profiles exhibited various levels of estrogenicity when tested in an in vitro estrogen receptor activation assay for both rhinoceros species, with profiles dominated by the microbial metabolite equol stimulating the highest levels of receptor activation. Finally, we found that SWR fertility varies significantly not only with respect to phytoestrogen profile, but also with respect to the abundance of several bacterial taxa and microbially derived phytoestrogen metabolites. Taken together, these data suggest that in addition to species differences in estrogen receptor sensitivity to phytoestrogens, reproductive outcomes may be driven by the gut microbiota’s transformation of dietary phytoestrogens in captive SWR females. IMPORTANCE Southern white rhinoceros (SWR) poaching has reached record levels, and captive infertility has rendered SWR assurance populations no longer self-sustaining. Previous work has identified dietary phytoestrogens as a likely cause of this problem. Here, we investigate the role of gut microbiota in this phenomenon by comparing two rhinoceros species to provide the first characterizations of gut microbiomes for any rhinoceros species. To our knowledge, our approach, combining parallel sequencing, mass spectrometry, and estrogen receptor activation assays, provides insight into the relationship between microbially mediated phytoestrogen metabolism and fertility that is novel for any vertebrate species. With this information, we plan to direct future work aimed at developing strategies to improve captive reproduction in the hope of alleviating their threat of extinction.
    • Immunocontraception of captive exotic species: v. prolonged antibody titers in dall sheep (ovis dalli dalli) and domestic goats (capra hircus) immunized with porcine zona pellucida

      Lyda, Robin O.; Frank, Kimberly M.; Wallace, Roberta; Lamberski, Nadine; Kirkpatrick, Jay F. (2013)
      Native porcine zona pellucida (PZP) immunocontraception has been used to inhibit fertility in more than 80 species of ungulates, although the duration of contraception efficacy varies among species in both Perissodactyla and Artiodactyla. This study examined anti-PZP antibody titers in Dall sheep and domestic goats at the Milwaukee County Zoo, and also Himalayan tahr and Armenian Mouflon sheep at the San Diego Zoo Safari Park, and, for comparison, Altai wapiti, lowland wisent, Javan banteng, and southern pudu at the San Diego Zoo Safari Park, all were given a primer dose and booster dose of PZP....
    • Reproductive life history of Thornicroft’s giraffe in Zambia: Giraffe reproduction in Zambia

      Bercovitch, Fred B.; Berry, Philip S.M.; (2010)
      Knowledge of the reproductive life history of giraffe in the wild is sparse. Giraffe have two fairly unusual reproductive patterns among large mammals: they can become pregnant while lactating, and calf mortality is extremely high. Longitudinal records are largely absent, so tracking reproductive parameters tends to combine information from captive and field studies. In this study, we examine longitudinal data obtained over a 33‐year period in one population of Thornicroft’s giraffe in order to chart their reproductive careers. We found that age at first parturition was 6.4 years, or slightly later than in captivity. Giraffe bred throughout the year, with cows producing offspring on average every 677.7 days. About half of the calves died before one year of age, but death of a calf did not reduce interbirth interval. We conclude that the lifetime reproductive success of giraffe is more dependent on longevity and calf survivorship than on reproductive rate.