• 98 Efficacy of commercial equine semen freezing extenders for cryopreservation of southern white rhinoceros (Ceratotherium simum simum) sperm

      Young, Carly; Ravida, Nicole; Pennington, Parker M.; Durrant, Barbara S. (2019)
      Once nearly extinct in the wild, the southern white rhinoceros is currently listed as near threatened by IUCN. This status is likely to change as poaching continues to escalate....
    • Analyzing the past to understand the future: Natural mating yields better reproductive rates than artificial insemination in the giant panda

      Li, Disheng; Wintle, Nathan J. P.; Zhang, Guiquan; Wang, Chengdong; Luo, Bo; Martin-Wintle, Meghan S.; Owen, Megan A.; Swaisgood, Ronald R. (2017)
      ...Here we analyze 21 years (1996–2016) of giant panda reproductive data from 304 insemination events to determine relative success rates of insemination methods and evaluate management strategies. The birth rate after natural mating was 60.7%, 50.6% for combined natural mating and artificial insemination techniques, and 18.5% for artificial insemination (AI)....
    • Assisted reproductive technologies in captive rhinoceroses

      Pennington, Parker M.; Durrant, Barbara S. (2019)
      Survival of the five remaining rhinoceros species is threatened. Four of the five species are in managed collections, but captive populations are not self-sustaining and low reproductive rates make population growth slow. Slow population growth, coupled with behavioural incompatibilities, acyclicity, low genetic diversity, and disease susceptibility, creates the need for assisted reproductive technologies (ARTs) to maintain genetic diversity while bolstering population numbers. Both published and unpublished data are included in this review of ARTs, to facilitate understanding consistencies and variations between and within each rhinoceros species. Progress has been made to address species-specific characteristics of reproductive physiology in rhinoceroses. This review outlines the ARTs that have been performed and identifies areas in need of research. In vivo technologies have resulted in live calves by artificial insemination, created genetic reservoirs through semen collection, and provided new avenues of gamete retrieval via ovum pickup. In vitro technologies have enabled genetic rescue post mortem and support early stage embryo production through oocyte maturation and fertilisation. As conservation efforts focus on rhinoceroses, improvement of existing techniques and development of new technologies will allow for a broader application of successful rhinoceros ARTs.
    • Chilled frogs are hot: hibernation and reproduction of the Endangered mountain yellow-legged frog Rana muscosa

      Santana, Frank E.; Swaisgood, Ronald R.; Lemm, Jeffrey M.; Fisher, Robert N.; Clark, Rulon W. (2015)
      In the face of the sixth great extinction crisis, it is imperative to establish effective breeding protocols for amphibian conservation breeding programs. Captive efforts should not proceed by trial and error, nor should they jump prematurely to assisted reproduction techniques, which can be invasive, difficult, costly, and, at times, counterproductive. Instead, conservation practitioners should first look to nature for guidance, and replicate key conditions found in nature in the captive environment, according to the ecological and behavioral requirements of the species. We tested the effect of a natural hibernation regime on reproductive behaviors and body condition in the Endangered mountain yellow-legged frog Rana muscosa. Hibernation had a clear positive effect on reproductive behavior, manifesting in vocal advertisement signaling, female receptivity, amplexus, and oviposition. These behaviors are critical components of courtship that lead to successful reproduction. Our main finding was that captive R. muscosa require a hibernation period for successful reproduction, as only hibernated females produced eggs and only hibernated males successfully fertilized eggs. Although hibernation also resulted in a reduced body condition, the reduction appeared to be minimal with no associated mortality. The importance of hibernation for reproduction is not surprising, since it is a major component of the conditions that R. muscosa experiences in the wild. Other amphibian conservation breeding programs can also benefit from a scientific approach that tests the effect of natural ecological conditions on reproduction. This will ensure that captive colonies maximize their role in providing genetic reservoirs for assurance and reintroduction efforts.
    • Demography of the giant otter (Pteronura brasiliensis) in Manu National Park, South-Eastern Peru: Implications for conservation

      Groenendijk, Jessica; Hajek, Frank; Johnson, Paul J.; Macdonald, David W.; Calvimontes, Jorge; Staib, Elke; Schenck, Christof (2014)
      The giant otter (Pteronura brasiliensis) is an endangered semi-aquatic carnivore of South America. We present findings on the demography of a population inhabiting the floodplain of Manu National Park, south-eastern Peru, arising from 14 annual dry season censuses over a 16 year period. The breeding system of territorial groups, including only a single breeding female with non-reproductive adult ‘helpers’, resulted in a low intrinsic rate of increase (0.03) and a slow recovery from decades of hunting for the pelt trade. This is explained by a combination of factors: (1) physiological traits such as late age at first reproduction and long generation time, (2) a high degree of reproductive skew, (3) small litters produced only once a year, and (4) a 50% mortality between den emergence and age of dispersal, as well as high mortality amongst dispersers (especially males). Female and male giant otters show similar traits with respect to average reproductive life-spans (female 5.4 yrs., male 5.2 yrs.) and average cub productivity (female 6.9, male 6.7 cubs per lifetime); the longest reproductive life spans were 11 and 13 years respectively. Individual reproductive success varied substantially and depended mainly on the duration of dominance tenure in the territory. When breeding females died, the reproductive position in the group was usually occupied by sisters or daughters (n = 11), with immigrant male partners. Male philopatry was not observed. The vulnerability of the Manu giant otter population to anthropogenic disturbance emphasises the importance of effective protection of core lake habitats in particular. Riverine forests are the most endangered ecosystem in the Department of Madre de Dios due to the concentration of gold mining, logging and agricultural activities in floodplains, highlighting the need for a giant otter habitat conservation corridor along the Madre de Dios River.
    • Detailed monitoring of a small but recovering population reveals sublethal effects of disease and unexpected interactions with supplemental feeding

      Tollington, S.; Greenwood, A.; Jones, C.G.; Hoeck, Paquita; Chowrimootoo, A.; Smith, D.; Richards, H.; Tatayah, V.; Groombridge, J.J. (2015)
      Infectious diseases are widely recognized to have substantial impact on wildlife populations. These impacts are sometimes exacerbated in small endangered populations, and therefore, the success of conservation reintroductions to aid the recovery of such species can be seriously threatened by outbreaks of infectious disease. Intensive management strategies associated with conservation reintroductions can further compound these negative effects in such populations. Exploring the sublethal effects of disease outbreaks among natural populations is challenging and requires longitudinal, individual life‐history data on patterns of reproductive success and other indicators of individual fitness. Long‐term monitoring data concerning detailed reproductive information of the reintroduced Mauritius parakeet (Psittacula echo ) population collected before, during and after a disease outbreak was investigated. Deleterious effects of an outbreak of beak and feather disease virus (BFDV ) were revealed on hatch success, but these effects were remarkably short‐lived and disproportionately associated with breeding pairs which took supplemental food. Individual BFDV infection status was not predicted by any genetic, environmental or conservation management factors and was not associated with any of our measures of immune function, perhaps suggesting immunological impairment. Experimental immunostimulation using the PHA (phytohaemagglutinin assay) challenge technique did, however, provoke a significant cellular immune response. We illustrate the resilience of this bottlenecked and once critically endangered, island‐endemic species to an epidemic outbreak of BFDV and highlight the value of systematic monitoring in revealing inconspicuous but nonetheless substantial ecological interactions. Our study demonstrates that the emergence of such an infectious disease in a population ordinarily associated with increased susceptibility does not necessarily lead to deleterious impacts on population growth and that negative effects on reproductive fitness can be short‐lived.
    • Differential success in obtaining gametes between male and female Australian temperate frogs by hormonal induction: A review

      Clulow, John; Pomering, Melissa; Herbert, Danielle; Upton, Rose; Calatayud, Natalie E.; Clulow, Simon; Mahony, Michael J.; Trudeau, Vance L. (2018)
      Most Australian frogs fall into two deeply split lineages, conveniently referred to as ground frogs (Myobatrachidae and Limnodynastidae) and tree frogs (Pelodryadidae). Species of both lineages are endangered because of the global chytrid pandemic, and there is increasing interest and research on the endocrine manipulation of reproduction to support the use of assisted reproductive technologies in conservation....
    • Dynamics of male-female multimodal signaling behavior across the estrous cycle in giant pandas (Ailuropoda melanoleuca)

      Owen, Megan A.; Swaisgood, Ronald R.; McGeehan, L.; Zhou, X.; Lindburg, Donald G. (2013)
      Giant panda courtship behavior includes multimodal signaling assemblages consisting of olfactory, vocal, and postural elements. While signaling is generally conspicuous, successful copulation is inconsistently achieved in captivity, even when female behavioral and physiological data indicate that ovulation is imminent. We set out to characterize these complex patterns of social behavior by observing interactions between 26 unique pairs of giant pandas housed in adjoining pens throughout the females' reproductive cycle....
    • Dynamics of male-female multimodal signaling behavior across the estrous cycle in giant pandas (Ailuropoda melanoleuca)

      Owen, Megan A.; Swaisgood, Ronald R.; McGeehan, Laura; Zhou, Xiaoping; Lindburg, Donald G.; Koenig, W. (2013)
      Giant panda courtship behavior includes multimodal signaling assemblages consisting of olfactory, vocal, and postural elements. While signaling is generally conspicuous, successful copulation is inconsistently achieved in captivity, even when female behavioral and physiological data indicate that ovulation is imminent. We set out to characterize these complex patterns of social behavior by observing interactions between 26 unique pairs of giant pandas housed in adjoining pens throughout the females' reproductive cycle….
    • Exploring the limits of saving a subspecies: The ethics and social dynamics of restoring northern white rhinos (Ceratotherium simum cottoni)

      Ryder, Oliver A.; Friese, Carrie; Greely, Henry T.; Sandler, Ronald; Saragusty, Joseph; Durrant, Barbara S.; Redford, Kent H. (2020)
      The northern white rhino (Ceratotherium simum cottoni) is functionally extinct with only two females left alive. However, cryopreserved material from a number of individuals represents the potential to produce additional individuals using advanced reproductive and genetic rescue technologies and perhaps eventually a population to return to their native range. If this could and were done, how should it be done responsibly and thoughtfully. What issues and questions of a technical, bioethical, and societal nature will it raise that need to be anticipated and addressed? Such issues are explored in this article by an interdisciplinary team assembled to provide context to the northern white rhino project of the San Diego Zoo Global.
    • Functional morphology of the female genital organs in the Peruvian red uakari monkey (Cacajao calvus ucayalii)

      Mayor, Pedro; Bowler, Mark; López-Plana, Carlos (2013)
      Functional morphology may provide important information that could improve methodologies for the diagnosis of the reproductive phase of females, and develop assisted breeding techniques for wildlife. This study examined features of genital organs in 19 Peruvian red uakari monkey (Cacajao calvus ucayalii) females in different reproductive stages, collected from wild animals hunted for food by rural communities in the North-eastern Peruvian Amazon, in order to provide knowledge on the reproductive physiology of this species …
    • Growth, reproduction and diet of Roatan Spiny-tailed Iguanas, Ctenosaura oedirhina, with notes on the status of the species

      Pasachnik, Stesha A. (2013)
      Roatan Spiny-tailed Iguanas, Ctenosaura oedirhina, are listed as Endangered by the IUCN Redlist Assessment and under Appendix II of Convention on International Trade of Endangered Species of Wild Fauna and Flora (CITES). These iguanas occur primarily on Roatan and Barbaretta, off the Caribbean coast of Honduras. Habitat destruction associated with development, small-scale agriculture, and exploitation for food and the pet trade are contributing to the decline of these iguanas. This species was described in 1987 (de Queiroz) when it was split from the sister taxon C. bakeri, found on the island of Utila, Honduras. Since its description little has been done to understand its biology or protect this narrow-range endemic. Herein, I examined the morphology and body condition of this species across its range and report on its reproductive biology and diet. Similar to many members of the Iguaninae, males are larger on average and have relatively longer tails than females. Likewise, reproductive and dietary data are consistent with those for closely related species. The body condition of both males and females was lower in more pristine study sites, indicating that supplemental feeding in developed areas may be having an effect. A female-biased sex ratio was found in sites protected by grassroots efforts, where the populations were large enough to be studied. Conservation measures should focus on alleviating the threats of harvesting and habitat destruction through increased law enforcement, outreach, and education.
    • Identification of California condor estrogen receptors 1 and 2 and their activation by endocrine disrupting chemicals

      Felton, Rachel G.; Steiner, Cynthia C.; Durrant, Barbara S.; Keisler, Duane H.; Milnes, Matthew R.; Tubbs, Christopher W. (2015)
      ...There is evidence that coastal-dwelling condors experience reproductive issues, such as eggshell thinning, likely resulting from exposure to endocrine-disrupting chemicals (EDCs). To address this problem, we have identified and cloned condor estrogen receptors (ESRs) 1 and 2 and characterized their activation by EDCs present in the coastal habitats where condors reside....
    • Induction of sperm hypermotility through membrane progestin receptor alpha (mPRα): A teleost model of rapid, multifaceted, nongenomic progestin signaling

      Tan, Wenxian; Pang, Yefei; Tubbs, Christopher W.; Thomas, Peter (2018)
      Rapid progestin effects on sperm physiology have been described in a variety of vertebrate species. Here, we briefly review the signaling pathways mediating rapid progestin induction of sperm hypermotility and increased fertility in two teleost species, Atlantic croaker and southern flounder....
    • Inter-aviary distance and visual access influence conservation breeding outcomes in a territorial, endangered bird

      Flanagan, Alison M.; Rutz, Christian; Farabaugh, Susan M.; Greggor, Alison L.; Masuda, Bryce M.; Swaisgood, Ronald R. (2020)
      Species extinctions are becoming a global crisis, affecting biodiversity and ecosystem services, with island populations being particularly vulnerable. In response, conservation managers are increasingly turning to ex situ conservation breeding programs to establish assurance populations and provide a source for release and re-establishment of wild populations. The 'Alalā (Hawaiian crow, Corvus hawaiiensis) is a critically endangered and territorial island corvid that became extinct in the wild in 2002, following a severe and prolonged population decline during the late 20th century....
    • Low birthrates and high levels of female reproductive inactivity may characterize the reproductive biology of wild Peruvian red uakaris (Cacajao calvus ucayalii)

      Mayor, Pedro; Bowler, Mark (2015)
      ...We collected reproductive organs from wild uakari monkeys hunted for subsistence by indigenous hunters and examined them for embryos or fetuses. We extrapolated birth dates to test for breeding seasonality and calculated birthrates....
    • Ovarian control and monitoring in amphibians

      Calatayud, Natalie E.; Stoops, M.; Durrant, Barbara S. (2018)
      Amphibian evolution spans over 350 million years ago, consequently this taxonomic group displays a wide, complex array of physiological adaptations and their diverse modes of reproduction are a prime example. Reproduction can be affected by taxonomy, geographic and altitudinal distribution, and environmental factors....
    • Phenotypic plasticity in the timing of reproduction in Andean bears

      Appleton, R. D.; Van Horn, Russell C.; Noyce, K. V.; Spady, T. J.; Swaisgood, Ronald R.; Arcese, P. (2018)
      Many factors influence whether mammals reproduce seasonally or continuously but disentangling them can be challenging in free‐living species that are hard to observe. We described the seasonality of reproduction in Andean bears (Tremarctos ornatus) in NW Peru (6°26′S, 79°33′W) to test for phenotypic plasticity in response to extrinsic cues.
    • Refining reproductive parameters for modelling sustainability and extinction in hunted primate populations in the Amazon

      Bowler, Mark; Anderson, Matthew J.; Montes, Daniel; Pérez, Pedro; Mayor, Pedro; Fenton, Brock; Fenton, Brock (2014)
      Primates are frequently hunted in Amazonia. Assessing the sustainability of hunting is essential to conservation planning. The most-used sustainability model, the ‘Production Model’, and more recent spatial models, rely on basic reproductive parameters for accuracy. These parameters are often crudely estimated. To date, parameters used for the Amazon’s most-hunted primate, the woolly monkey (Lagothrix spp.), come from captive populations in the 1960s, when captive births were rare. Furthermore, woolly monkeys have since been split into five species. We provide reproductive parameters calculated by examining the reproductive organs of female Poeppig’s woolly monkeys (Lagothrix poeppigii), collected by hunters as part of their normal subsistence activity. Production was 0.48–0.54 young per female per year, and an interbirth interval of 22.3 to 25.2 months, similar to parameters from captive populations. However, breeding was seasonal, which imposes limits on the maximum reproductive rate attainable. We recommend the use of spatial models over the Production Model, since they are less sensitive to error in estimated reproductive rates. Further refinements to reproductive parameters are needed for most primate taxa. Methods like ours verify the suitability of captive reproductive rates for sustainability analysis and population modelling for populations under differing conditions of hunting pressure and seasonality. Without such research, population modelling is based largely on guesswork.
    • Regulation of endocrine systems by the microbiome: Perspectives from comparative animal models

      Williams, Candace L.; Garcia-Reyero, Natàlia; Martyniuk, Christopher J.; Tubbs, Christopher W.; Bisesi, Joseph H. (2020)
      The microbiome regulates endocrine systems and influences many aspects of hormone signaling. Using examples from different animal taxa, we highlight the state of the science in microbiome research as it relates to endocrinology and endocrine disruption research....