• Estimating mammalian species richness and occupancy in tropical forest canopies with arboreal camera traps

      Bowler, Mark; Tobler, Mathias W.; Endress, Bryan A.; Gilmore, Michael P.; Anderson, Matthew J. (2017)
      Large and medium-bodied rainforest canopy mammals are typically surveyed using line transects, but these are labour intensive and usually ignore nocturnal species. Camera traps have become the preferred tool for assessing terrestrial mammal communities, but have rarely been used for arboreal species. Here, we compare the efficiency of arboreal camera trapping with line transects for inventorying medium and large-sized arboreal mammals, and assess the viability of using camera traps in trees to model habitat occupancy. We installed 42 camera traps, spaced 2 km apart, in the canopy of the Maijuna-Kichwa Regional Conservation Area, Peru and walked 2014 km of diurnal line transects on 22 trails at the same site. We compared the efficiency of each method using species accumulation curves. We applied a multi-species occupancy model, while examining the effect of camera height on detection probabilities, including the distance from a village and from a river as covariates to examine variability in habitat occupancy. In 3147 camera days, 18 species of arboreal medium and large-sized mammals were detected by cameras, while 11 species were recorded on line transects. Ten of these species were detected by both methods. Diurnal species were detected more quickly and with less effort using arboreal camera trapping than using diurnal line transects at the same site, although some species were more easily detected during line transects. Habitat occupancy was positively correlated with distance from the village for two species, and negatively correlated with distance from the river for one. Detection probabilities increased modestly with camera height. Practical limitations of arboreal camera trapping include the requirement for specialized climbing techniques, as well as increased potential for false triggers, requiring extended processing time. Arboreal camera trapping is an efficient method for inventorying arboreal mammals and a viable option for studying their distribution relative to environmental or anthropogenic variables when abundance or density estimates are not required.
    • Estimating past and future male loss in three Zambian lion populations

      Becker, Matthew S.; Watson, Fred G.R.; Droge, Egil; Leigh, Kellie; Carlson, Ron S.; Carlson, Anne A. (2013)
      …Zambia contains viable lion populations of considerable importance for photographic and hunting tourism, but long‐term lion demographic data do not exist to guide recent management directives and population projections under different strategies. We described population size, as well as age and sex structure of lions in 3 Zambian national park populations bordering hunting areas, and found them to be male‐depleted relative to other systems….
    • 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.…
    • Ethical considerations when conservation research involves people

      Brittain, Stephanie; Ibbett, Harriet; Lange, Emiel; Dorward, Leejiah; Hoyte, Simon; Marino, Agnese; Milner-Gulland, E. J.; Newth, Julia; Rakotonarivo, Sarobidy; Veríssimo, Diogo; et al. (2020)
      Social science is becoming increasingly important in conservation, with more studies involving methodologies that collect data from and about people. Conservation science is a normative and applied discipline designed to support and inform management and practice....
    • Evaluating recovery potential of the northern white rhinoceros from cryopreserved somatic cells

      Tunstall, Tate S.; Kock, Richard; Vahala, Jiri; Diekhans, Mark; Fiddes, Ian; Armstrong, Joel; Paten, Benedikt; Ryder, Oliver A.; Steiner, Cynthia C. (2018)
      The critically endangered northern white rhinoceros is believed to be extinct in the wild, with the recent death of the last male leaving only two remaining individuals in captivity. Its extinction would appear inevitable, but the development of advanced cell and reproductive technologies such as cloning by nuclear transfer and the artificial production of gametes via stem cells differentiation offer a second chance for its survival. In this work, we analyzed genome-wide levels of genetic diversity, inbreeding, population history, and demography of the white rhinoceros sequenced from cryopreserved somatic cells, with the goal of informing how genetically valuable individuals could be used in future efforts toward the genetic rescue of the northern white rhinoceros. We present the first sequenced genomes of the northern white rhinoceros, which show relatively high levels of heterozygosity and an average genetic divergence of 0.1% compared with the southern subspecies. The two white rhinoceros subspecies appear to be closely related, with low genetic admixture and a divergent time <80,000 yr ago. Inbreeding, as measured by runs of homozygosity, appears slightly higher in the southern than the northern white rhinoceros. This work demonstrates the value of the northern white rhinoceros cryopreserved genetic material as a potential gene pool for saving this subspecies from extinction.
    • Evaluating seed banking capacity and propagation potential of endangered Sierra Bermeja grasses: Aristida chaseae and Aristida portoricensis

      Maschinski, Joyce; Possley, Jennifer; Lange, James; Monsegur Rivera, Omar A.; Heineman, Katherine D. (2018)
      Of the 2329 plant species that are native to Puerto Rico, 188 are grasses (Poaceae) and nearly 20% of those are critically imperiled. To address gaps in knowledge of US endangered Aristida chaseae (Chase’s Threeawn) and Aristida portoricensis (Pelos del Diablo) from Sierra Bermeja in southwestern Puerto Rico, we conducted experiments to determine viability of seeds produced in the wild, germination requirements, and ability to be stored under cold, dry conditions.
    • Evaluating the application of scale frequency to estimate the size of pangolin scale seizures

      Ullmann, Tessa; Veríssimo, Diogo; Challender, Daniel W. S. (2019)
      All eight species of pangolin are principally threatened by overexploitation, both for international trafficking and local use. Much illegal trade involves scales, but there is an absence of robust conversion parameters for estimating the number of different pangolin species in given seizures. Such parameters are critical in order to accurately characterize pangolin trafficking and understand the magnitude and impact of exploitation on populations. In this study, we calculated the number of scales on 66 museum specimens representing all eight extant pangolin species from the genera Manis, Phataginus, and Smutsia, and developed a method for estimating the number of pangolins in given seizures of scales based on scale frequency. Our statistical analyses found significant variation in scale number in inter-species terms (ranging from 382 for Temminck's ground pangolin to 940 for the Philippine pangolin), and in intra-species terms, with substantial variation in the giant pangolin (509–664 scales) and minimal variation in the Chinese pangolin (527–581 scales). We discuss application of the developed sampling method in a real world context and critically appraise it against existing methods. The knowledge generated in this study should assist in understanding pangolin trafficking dynamics, though there remains a need for accurate conversion parameters for estimating the number of pangolins in illegal trade, especially for the Indian and African species.
    • Everybody loses: intraspecific competition induces tragedy of the commons in Allenby's gerbils

      Berger-Tal, Oded; Embar, Keren; Kotler, Burt P.; Saltz, David (2015)
      Interference competition may lead to a tragedy of the commons in which individuals driven by self‐interest reduce the fitness of the entire group. We investigated this hypothesis in Allenby's gerbils, Gerbillus andersoni allenbyi , by comparing foraging behaviors of single vs. pairs of gerbils....
    • Everything you want to know about the giant panda

      Swaisgood, Ronald R. (2015)
      Book review of Pan, Wenshi, Lu Zhi, Zhu Xiaojian, Wang Dajun, Wang Hao, Long Yu, Fu Dali, and Zhou Xin. 2014 (Chinese edition, 2001). A chance for lasting survival: ecology and behavior of wild giant pandas. Smithsonian Institution Scholarly Press, Washington, D.C. xx þ 349 p. $39.95, ISBN: 978-1-935623-17-5 (alk. paper).
    • Evidence for dominant males but not choosy females in an insular rock iguana

      Moss, Jeanette B.; Gerber, Glenn P.; Schwirian, Aumbriel; Jackson, Anna C.; Welch, Mark E. (2018)
      In natural populations susceptible to inbreeding depression, behaviors such as female promiscuity and disassortative mating may enhance the production of outbred progeny and help maintain genetic variation at the population-level. However, empirical tests of such hypotheses have largely focused on mating systems in which female choice is known to play a large role....
    • Evolutionary and functional novelty of pancreatic ribonuclease: a study of Musteloidea (order Carnivora)

      Liu, Jiang; Wang, Xiao-ping; Cho, Soochin; Lim, Burton K.; Irwin, David M.; Ryder, Oliver A.; Zhang, Ya-ping; Yu, Li (2014)
      Pancreatic ribonuclease (RNASE1) is a digestive enzyme that has been one of the key models in studies of evolutionary innovation and functional diversification. It has been believed that the RNASE1 gene duplications are correlated with the plant-feeding adaptation of foregut-fermenting herbivores. Here, we characterized RNASE1 genes from Caniformia, which has a simple digestive system and lacks microbial digestion typical of herbivores, in an unprecedented scope based on both gene sequence and tissue expression analyses. Remarkably, the results yielded new hypotheses regarding the evolution and the function of Caniformia RNASE1 genes. Four independent gene duplication events in the families of superfamily Musteloidea, including Procyonidae, Ailuridae, Mephitidae and Mustelidae, were recovered, rejecting previous Mustelidae-specific duplication hypothesis, but supporting Musteloidea duplication hypothesis. Moreover, our analyses revealed pronounced differences among the RNASE1 gene copies regarding their selection pressures, pI values and tissue expression patterns, suggesting the differences in their physiological functions. Notably, the expression analyses detected the transcription of a RNASE1 pseudogene in several tissues, raising the possibility that pseudogenes are also a potential source during the RNase functional diversification. In sum, the present work demonstrated a far more complex and intriguing evolutionary pattern and functional diversity of mammalian ribonuclease than previously thought.
    • Evolutionary genomics and conservation of the endangered Przewalski’s horse

      Der Sarkissian, Clio; Ermini, Luca; Schubert, Mikkel Heide; Yang, Melinda A.; Librado, Pablo; Fumagalli, Matteo; Jónsson, Hákon; Bar-Gal, Gila Kahila; Albrechtsen, Anders; Vieira, Filipe G.; et al. (2015)
      Przewalski’s horses (PHs, Equus ferus ssp. przewalskii) were discovered in the Asian steppes in the 1870s and represent the last remaining true wild horses. PHs became extinct in the wild in the 1960s but survived in captivity, thanks to major conservation efforts....
    • Examination of enrichment using space and food for African elephants (Loxodonta africana) at the San Diego Zoo Safari Park

      Hacker, CE; Miller, Lance J.; Schulte, BA (2018)
      Concern for elephant welfare in zoological facilities has prompted a number of exhibit and management modifications, including those involving enrichment. Knowledge of how these changes impact indicators of welfare, such as elephant movement and behaviour, is crucial for continued improvement of elephant husbandry and care....
    • Examining the efficacy of anti-predator training for increasing survival in conservation translocations: a systematic review protocol

      Greggor, Alison L.; Price, Catherine J.; Shier, Debra M. (2019)
      Background How animals respond to predators can have consequences when they are reintroduced into the wild or translocated to new habitats. Animals raised in captivity often lack adequate experience with predators, and wild animals can be ill-equipped to respond to invasive predators. When these animals are released or translocated for conservation purposes, their naivety can jeopardize their survival and the outcome of the conservation intervention. Anti-predator training, i.e. the purposeful exposure of animals to predators or predatory-like cues for promoting predatory learning and awareness, is often suggested to be a useful tool in combating prey naivety. However, the prevalence of such training and the evidence for its effectiveness in conservation settings are currently unknown. We detail a set of protocols aimed at resolving both of these unknowns. Methods We will aim to gather studies from multiple databases and grey literature sources which document the occurrence of anti-predator training. We will search beyond the conservation management literature to also cover interventions aimed at promoting anti-predator behaviour in commercial contexts and other academic fields (e.g. animal cognition, behavioral ecology). Studies will be screened in two phases. The first stage of screening will collect studies that conduct anti-predator training. Metadata from this stage will help highlight biases in the use of anti-predator training across geographic locations, funding contexts and taxonomic groups. We will then further screen for research that measures training efficacy either by using learning assessments, designating experimental groups, or by collecting post-release survival data. A narrative synthesis at this stage will describe the relative proportion of studies that measure the efficacy of their training. The smaller research pool will then be systematically reviewed to assess the efficacy of anti-predator training. We will attempt to extract data from all studies which assess efficacy, judging study validity and conducting a meta-analysis if sufficient evidence is found. By creating two stages to our screening and review of evidence, we will be able to better judge the biases and reliability of the efficacy evidence we find.
    • Exit strategies for wildlife conservation: why they are rare and why every institution needs one

      Ruiz-Miranda, Carlos R.; Vilchis, L. Ignacio; Swaisgood, Ronald R. (2020)
      Exit strategies – plans to end involvement in a project once selected criteria have been reached – are rare in conservation planning but can play a vital role in the conservation planning process; such strategies also prepare the institution, its staff, its partners, and a wider group of stakeholders for eventual success or failure and signal when it is time to move on. Exit strategies may indicate that the project has been terminated but may also signal success, or that project leadership has transitioned to another, more appropriate entity. We address why exit strategies are uncommon in conservation, why they are essential, what determines when to transition or leave, and how to plan for circumstances afterwards. A good exit strategy addresses financial and legal liabilities to employees, publication of results, and ownership of data, among other things. A comprehensive, thoughtful strategy can lead to “beautiful exits” that minimize negative consequences to the project.
    • Experimental habitat restoration for conserved species using ecosystem engineers and vegetation management

      Hennessy, Sarah McCullough; Deutschman, D. H.; Shier, Debra M.; Nordstrom, Lisa A.; Lenihan, C.; Montagne, J.P.; Wisinski, Colleen L.; Swaisgood, Ronald R. (2016)
      We manipulated vegetation and the ecosystem engineer California ground squirrel, Otospermophilus beecheyi, in a replicated, large-scale field experiment for 2 years, and monitored through a third year…. The overarching goal of this experiment was to provide conservation managers with a cost-effective tool for restoring degraded habitats to a hybrid ecosystem state with improved suitability for species of conservation concern, in this case, the western burrowing owl Athene cunicularia hypugaea.
    • Exploring saiga horn consumption in Singapore

      Theng, Meryl; Glikman, Jenny A.; Milner-Gulland, E. J. (2018)
      The Critically Endangered saiga antelope Saiga tatarica faces an uncertain future, with populations dwindling from epidemics in its range countries, and ongoing demand for its horns in the traditional Chinese medicine trade....
    • 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.
    • External reinfection of a fungal pathogen does not contribute to pathogen growth

      DiRenzo, Graziella V.; Tunstall, Tate S.; Ibáñez, Roberto; deVries, Maya S.; Longo, Ana V.; Zamudio, Kelly R.; Lips, Karen R. (2018)
      Chytridiomycosis is an emerging infectious disease of amphibians caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), which has led to devastating declines in amphibian populations worldwide. Current theory predicts that Bd infections are maintained through both reproduction on the host’s skin and reinfection from sources outside of the host....