• Cerebral Angiostrongylus cantonensis infection in a captive African pygmy falcon (Polihierax semitorquatus) in southern California

      Burns, Rachel E.; Bicknese, Elizabeth; Qvarnstrom, Yvonne; DeLeon-Carnes, Marlene; Drew, Clifton P.; Gardiner, Chris H.; Rideout, Bruce (2014)
      A 10-month-old, female African pygmy falcon (Polihierax semitorquatus) hatched and housed at the San Diego Zoo developed neurologic signs and died from a cerebral infection with the rat lungworm Angiostrongylus cantonensis…. To the authors’ knowledge, this infection has not previously been reported in a bird in the United States and has not been known to be naturally acquired in any species in this region of the world. The source of the infection was not definitively determined but was possibly feeder geckos (Hemidactylus frenatus) imported from Southeast Asia where the parasite is endemic.
    • Chromosomal variation and perinatal mortality in San Diego zoo Soemmerring's gazelles

      Steiner, Cynthia C.; Charter, Suellen J.; Goddard, Natalie; Davis, Heidi; Brandt, Margot; Houck, Marlys L.; Ryder, Oliver A. (2015)
      …For the past 35 years, the San Diego Zoo Global (SDZG) captive population of Soemmerring's gazelles has revealed complex karyotypes resulting from chromosomal translocations with diploid numbers ranging from 34 to 39... Low levels of genetic distance and nucleotide diversity among individuals, in addition to high relatedness values, suggested that outbreeding is less of a concern than inbreeding for maintaining a sustainable captive population….
    • Detection of oocyte perivitelline membrane-bound sperm: A tool for avian collection management

      Croyle, Kaitlin E.; Durrant, Barbara S.; Jensen, Thomas (2015)
      The success and sustainability of an avian breeding programme depend on managing productive and unproductive pairs. Given that each breeding season can be of immeasurable importance, it is critical to resolve pair fertility issues quickly. Such problems are traditionally diagnosed through behavioural observations, egg lay history and hatch rates, with a decision to re-pair generally taking one or more breeding seasons. In pairs producing incubated eggs that show little or no signs of embryonic development, determining fertility is difficult. Incorporating a technique to assess sperm presence on the oocyte could, in conjunction with behaviour and other data, facilitate a more timely re-pair decision. Detection of perivitelline membrane-bound (PVMbound) sperm verifies successful copulation, sperm production and sperm functionality. Alternatively, a lack of detectable sperm, at least in freshly laid eggs, suggests no mating, lack of sperm production/function or sperm–oviduct incompatibility. This study demonstrated PVM-bound sperm detection by Hoechst staining in fresh to 24-day-incubated exotic eggs from 39 species representing 13 orders. However, a rapid and significant time-dependent loss of detectable PVM-bound sperm was observed following incubation of chicken eggs. The PCR detection of sperm in seven species, including two bacterially infected eggs, demonstrated that this method was not as reliable as visual detection using Hoechst staining. The absence of amplicons in visually positive PVMs was presumably due to large PVM size and low sperm count, resulting in DNA concentrations too low for standard PCR detection. In summary, this study demonstrated the feasibility and limitations of using PVM-bound sperm detection as a management tool for exotic avian species. We verified that sperm presence or absence on fluorescence microscopy can aid in the differentiation of fertile from infertile eggs to assist breeding managers in making prompt decisions for pair rearrangements. This protocol is currently used to manage several breeding pairs in San Diego Zoo global avian conservation programmes.
    • 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.
    • Fat-soluble vitamin and mineral comparisons between zoo-based and free-ranging koalas (phascolarctos cinereus)

      Schmidt, Debra A.; Pye, Geoffrey W.; Hamlin-Andrus, Chris C.; Ellis, William A.; Ellersieck, Mark R.; Chen, Tai C.; Holick, Michael F. (2013)
      As part of a health investigation on koalas at San Diego Zoo, serum samples were analyzed from 18 free-ranging and 22 zoo-based koalas, Phascolarctos cinereus. Serum concentrations of calcium, chloride, cobalt, copper, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, zinc, and vitamins A, E, and 25(OH)D3 were quantified....
    • Fostering “Little Green Guards ” through a collaborative partnership to create an effective conservation education program for rural children in Guizhou, China

      Tan, Chia L.; Yang, Y.; Niu, Kefeng; Lei, Shi; Weiyong, Zhang; Riondato, Isidoro; Giacoma, Cristina; Balletto, Emilio; Gamba, Marco; John, A. Phillips (2013)
      San Diego Zoo Global (USA), Fanjingshan National Nature Reserve Administration (China), and the University of Torino (Italy) have partnered in a collaborative effort to promote environmental sustainability and biodiversity conservation in Guizhou, China. The objectives of the partnership are twofold: (i) train researchers and wildlife professionals using a multidisciplinary program that employs the latest methods and tools in order to deepen their understanding of wildlife and the environment, and (ii) foster positive attitudes and behaviour toward wildlife in rural children through a creative education program called the Little Green Guards. A recent development of the education program is the Little Green Guards Club for children whose houses border nature reserves. During club meetings, staff of the three cooperating institutions and volunteers participated in teaching English and natural history lessons. Club activities included animal themed art projects, games, movies, and field trips designed to cultivate empathy for animals and appreciation for nature in these children. Evaluations conducted before and after implementation of the education program showed a significant increase in children’s knowledge of and affection for wildlife, and sometimes coincided with positive behavioural changes toward native species. Here we feature our collaborative effort in China as a model which can be adopted in other geographic regions where species and habitat conservation must become a top priority. We will discuss the role of Universities in critical assessment of previous experiences in order to enhance the effectiveness of cooperation with other development stakeholders (e.g. governmental and local authorities, civil society and NGOs, foundations and private companies, and local associations).
    • Histopathologic findings in free-ranging California hummingbirds, 1996–2017

      Magagna, Michelle; Noland, Erica; Tell, Lisa A.; Purdin, Guthrum; Rideout, Bruce; Lipman, Max W.; Agnew, Dalen (2018)
      A histopathologic study of free-ranging hummingbirds in California was performed to identify mortality trends. Tissues from 61 wild hummingbirds representing five native California species collected by the San Diego Zoo from 1996 to 2016 or the Lindsay Wildlife Experience from 2015 to 2017 were histologically examined....
    • Lessons from a retrospective analysis of a 5-yr period of preshipment testing at San Diego Zoo: a risk-based approach to preshipment testing may benefit animal welfare

      Marinkovich, Matt; Wallace, Chelsea; Morris, Pat J.; Rideout, Bruce; Pye, Geoffrey W. (2016)
      ...An alternative disease risk-based approach, based on a comprehensive surveillance program including necropsy and preventive medicine examination testing and data, has been in practice since 2006 between the San Diego Zoo and San Diego Zoo Safari Park. A retrospective analysis, evaluating comprehensive necropsy data and preshipment testing over a 5-yr study period, was performed to determine the viability of this model for use with sending animals to other institutions. Animals (607 birds, 704 reptiles and amphibians, and 341 mammals) were shipped to 116 Association of Zoos and Aquariums (AZA)-accredited and 29 non–AZA-accredited institutions....
    • Space use as an indicator of enclosure appropriateness in African wild dogs (Lycaon pictus)

      Hunter, Sally C.; Gusset, Markus; Miller, Lance J.; Somers, Michael J. (2014)
      A clear understanding of space use is required to more fully understand biological requirements of nonhuman animals in zoos, aid the design of exhibits, and maximize the animals' welfare. This study used electivity indexes to assess space use of two packs of African wild dogs (Lycaon pictus) and the appropriateness of two naturalistic, outdoor enclosures at the San Diego Zoo and Bronx Zoo....
    • The influence of ambient noise on maternal behavior in a Bornean sun bear (Helarctos malayanus euryspilus)

      Owen, Megan A.; Hall, S.; Bryant, L.; Swaisgood, Ronald R. (2014)
      …Here we correlate behavioral and vocal patterns in a Bornean sun bear (Helarctos malayanus euryspilus ) mother and cub with ambient noise levels during the 6‐month post‐partum period. We hypothesized that loud ambient noise would be correlated with changes in behavior, and predicted that noise would be negatively correlated with maternal care behavior, potentially masking cub vocalizations or providing a distraction to the mother….
    • Using the gut microbiota as a novel tool for examining colobine primate GI health

      Amato, Katherine R.; Metcalf, Jessica L.; Song, Se Jin; Hale, Vanessa L.; Clayton, Jonathan; Ackermann, Gail; Humphrey, Greg; Niu, Kefeng; Cui, Duoying; Zhao, Hongxia; et al. (2016)
      Primates of the Colobinae subfamily are highly folivorous. They possess a sacculated foregut and are believed to rely on a specialized gut microbiota to extract sufficient energy from their hard-to-digest diet. Although many colobines are endangered and would benefit from captive breeding programs, maintaining healthy captive populations of colobines can be difficult since they commonly suffer from morbidity and mortality due to gastrointestinal (GI) distress of unknown cause. While there is speculation that this GI distress may be associated with a dysbiosis of the gut microbiota, no study has directly examined the role of the gut microbiota in colobine GI health. In this study, we used high-throughput sequencing to examine the gut microbiota of three genera of colobines housed at the San Diego Zoo: doucs (Pygathrix) (N=7), colobus monkeys (Colobus) (N=4), and langurs (Trachypithecus) (N=5). Our data indicated that GI-healthy doucs, langurs, and colobus monkeys possess a distinct gut microbiota. In addition, GI-unhealthy doucs exhibited a different gut microbiota compared to GI-healthy individuals, including reduced relative abundances of anti-inflammatory Akkermansia. Finally, by comparing samples from wild and captive Asian colobines, we found that captive colobines generally exhibited higher relative abundances of potential pathogens such as Desulfovibrio and Methanobrevibacter compared to wild colobines, implying an increased risk of gut microbial dysbiosis. Together, these results suggest an association between the gut microbiota and GI illness of unknown cause in doucs. Further studies are necessary to corroborate these findings and determine cause-and-effect relationships. Additionally, we found minimal variation in the diversity and composition of the gut microbiota along the colobine GI tract, suggesting that fecal samples may be sufficient for describing the colobine gut microbiota. If these findings can be validated in wild individuals, it will facilitate the rapid expansion of colobine gut microbiome research.
    • Using tri-axial accelerometers to identify wild polar bear behaviors

      Pagano, Anthony M.; Rode, K. D.; Cutting, A; Owen, Megan A.; Jensen, S; Ware, J. V.; Robbins, Ct; Durner, Gm; Atwood, Todd C.; Obbard, M. E.; et al. (2017)
      Tri-axial accelerometers have been used to remotely identify the behaviors of a wide range of taxa. Assigning behaviors to accelerometer data often involves the use of captive animals or surrogate species, as their accelerometer signatures are generally assumed to be similar to those of their wild counterparts. However, this has rarely been tested. Validated accelerometer data are needed for polar bears Ursus maritimus to understand how habitat conditions may influence behavior and energy demands. We used accelerometer and water conductivity data to remotely distinguish 10 polar bear behaviors. We calibrated accelerometer and conductivity data collected from collars with behaviors observed from video-recorded captive polar bears and brown bears U. arctos, and with video from camera collars deployed on free-ranging polar bears on sea ice and on land. We used random forest models to predict behaviors and found strong ability to discriminate the most common wild polar bear behaviors using a combination of accelerometer and conductivity sensor data from captive or wild polar bears. In contrast, models using data from captive brown bears failed to reliably distinguish most active behaviors in wild polar bears. Our ability to discriminate behavior was greatest when species- and habitat-specific data from wild individuals were used to train models. Data from captive individuals may be suitable for calibrating accelerometers, but may provide reduced ability to discriminate some behaviors. The accelerometer calibrations developed here provide a method to quantify polar bear behaviors to evaluate the impacts of declines in Arctic sea ice.
    • Validation of mercury tip-switch and accelerometer activity sensors for identifying resting and active behavior in bears

      Ware, Jasmine V.; Rode, Karyn D.; Pagano, Anthony M.; Bromaghin, Jeffrey F.; Robbins, Charles T.; Erlenbach, Joy; Jensen, Shannon; Cutting, Amy; Nicassio-Hiskey, Nicole; Hash, Amy; et al. (2015)
      In this study, we examined the performance of a mercury tip-switch and a tri-axial accelerometer housed in collars to determine whether sensor data can be accurately classified as resting and active behaviors and whether data are comparable for the 2 sensor types. Five captive bears (3 polar [Ursus maritimus] and 2 brown [U. arctos horribilis]) were fitted with a collar specially designed to internally house the sensors. The bears’ behaviors were recorded, classified, and then compared with sensor readings…
    • Whole-genome analysis of mycobacteria from birds at the San Diego Zoo

      Pfeiffer, Wayne; Braun, Josephine; Burchell, Jennifer; Witte, Carmel L.; Rideout, Bruce (2017)
      Methods Mycobacteria isolated from more than 100 birds diagnosed with avian mycobacteriosis at the San Diego Zoo and its Safari Park were cultured postmortem and had their whole genomes sequenced. Computational workflows were developed and applied to identify the mycobacterial species in each DNA sample, to find single-nucleotide polymorphisms (SNPs) between samples of the same species, to further differentiate SNPs between as many as three different genotypes within a single sample, and to identify which samples are closely clustered genomically. Results Nine species of mycobacteria were found in 123 samples from 105 birds. The most common species were Mycobacterium avium and Mycobacterium genavense, which were in 49 and 48 birds, respectively. Most birds contained only a single mycobacterial species, but two birds contained a mixture of two species. The M. avium samples represent diverse strains of M. avium avium and M. avium hominissuis, with many pairs of samples differing by hundreds or thousands of SNPs across their common genome. By contrast, the M. genavense samples are much closer genomically; samples from 46 of 48 birds differ from each other by less than 110 SNPs. Some birds contained two, three, or even four genotypes of the same bacterial species. Such infections were found in 4 of 49 birds (8%) with M. avium and in 11 of 48 birds (23%) with M. genavense. Most were mixed infections, in which the bird was infected by multiple mycobacterial strains, but three infections with two genotypes differing by ≤ 10 SNPs were likely the result of within-host evolution. The samples from 31 birds with M. avium can be grouped into nine clusters within which any sample is ≤ 12 SNPs from at least one other sample in the cluster. Similarly, the samples from 40 birds with M. genavense can be grouped into ten such clusters. Information about these genomic clusters is being used in an ongoing, companion study of mycobacterial transmission to help inform management of bird collections.