• Health risks from lead-based ammunition in the environment

      Bellinger, David C.; Burger, Joanna; Cade, Tom J.; Cory-Slechta, Deborah A.; Finkelstein, Myra; Hu, Howard; Kosnett, Michael; Landrigan, Philip J.; Lanphear, Bruce; Pokras, Mark A.; et al. (2013)
      ...No rational deliberation about the use of lead-based ammunition can ignore the overwhelming evidence for the toxic effects of lead, or that the discharge of lead bullets and shot into the environment poses significant risks of lead exposure to humans and wildlife. Given the availability of non-lead ammunition for shooting and hunting (Thomas 2013), the use of lead-based ammunition that introduces lead into the environment can be reduced and eventually eliminated. This seems to be a reasonable and equitable action to protect the health of humans and wildlife....
    • Hearing sensitivity in context: Conservation implications for a highly vocal endangered species

      Owen, Megan A.; Keating, Jennifer L.; Denes, Samuel K.; Hawk, Kathy; Fiore, Angela; Thatcher, Julie; Becerra, Jennifer; Hall, Suzanne; Swaisgood, Ronald R. (2016)
      Hearing sensitivity is a fundamental determinant of a species’ vulnerability to anthropogenic noise, however little is known about the hearing capacities of most conservation dependent species. When audiometric data are integrated with other aspects of species’ acoustic ecology, life history, and characteristic habitat topography and soundscape, predictions can be made regarding probable vulnerability to the negative impacts of different types of anthropogenic noise. Here we used an adaptive psychoacoustic technique to measure hearing thresholds in the endangered giant panda; a species that uses acoustic communication to coordinate reproduction. Our results suggest that giant pandas have functional hearing into the ultrasonic range, with good sensitivity between 10.0 and 16.0 kHz, and best sensitivity measured at 12.5–14.0 kHz. We estimated the lower and upper limits of functional hearing as 0.10 and 70.0 kHz respectively. While these results suggest that panda hearing is similar to that of some other terrestrial carnivores, panda hearing thresholds above 14.0 kHz were significantly lower (i.e., more sensitive) than those of the polar bear, the only other bear species for which data are available. We discuss the implications of this divergence, as well as the relationship between hearing sensitivity and the spectral parameters of panda vocalizations. We suggest that these data, placed in context, can be used towards the development of a sensory-based model of noise disturbance for the species.
    • Hepatitis and splenitis due to systemic tetratrichomoniasis in an American white pelican (Pelecanus erythrorhynchos)

      Burns, Rachel E.; Braun, Josephine; Armién, Aníbal G.; Rideout, Bruce (2013)
      A free-ranging, young adult, female American white pelican (Pelecanus erythrorhynchos), found dead on the grounds of the San Diego Zoo Safari Park in Southern California, had severe multifocal to coalescing necrotizing hepatitis and splenitis on postmortem examination. Histologically, within the large areas of necrosis were myriad pleomorphic, 5–20 µm in diameter, protozoal organisms with 1 to multiple nuclei. Ultrastructurally, the organisms were consistent with a trichomonad flagellate. Polymerase chain reaction and sequencing of the small subunit ribosomal RNA gene identified nucleotide sequences with 99% identity to Tetratrichomonas gallinarum, which is a common inhabitant of the intestinal tract of galliform and anseriform birds that has occasionally been associated with disease, including typhlitis and hepatitis. Damage to the cecal mucosa in the pelican from trematodes and secondary bacterial infection could have allowed invasion and systemic dissemination of the organism. Exposure of the pelican to a variety of native and exotic anseriform and galliform birds at the zoological institution could have led to cross-species infection and severe manifestation of disease in a novel host.
    • Heterozygosity–Fitness Correlations Reveal Inbreeding Depression in Neonatal Body Size in a Critically Endangered Rock Iguana

      Moss, Jeanette B.; Gerber, Glenn P.; Welch, Mark E. (Oxford University Press (OUP), 2019)
      Inbreeding depression, though challenging to identify in nature, may play an important role in regulating the dynamics of small and isolated populations. Conversely, greater expression of genetic load can enhance opportunities for natural selection. Conditional expression concentrates these opportunities for selection and may lead to failure of detection. This study investigates the possibility for age-dependent expression of inbreeding depression in a critically endangered population of rock iguanas, Cyclura nubila caymanensis. We employ heterozygote-fitness correlations to examine the contributions of individual genetic factors to body size, a fitness-related trait. Nonsignificant reductions in homozygosity (up to 7%) were detected between neonates and individuals surviving past their first year, which may reflect natural absorption of inbreeding effects by this small, fecund population. The majority of variation in neonate body size was attributed to maternal or environmental effects (i.e., clutch identity and incubation length); however, heterozygosity across 22 microsatellite loci also contributed significantly and positively to model predictions. Conversely, effects of heterozygosity on fitness were not detectable when adults were examined, suggesting that inbreeding depression in body size may be age dependent in this taxon. Overall, these findings emphasize the importance of taking holistic, cross-generational approaches to genetic monitoring of endangered populations.
    • Hiding in plain sight: a study on camouflage and habitat selection in a slow-moving desert herbivore

      Nafus, Melia G.; Germano, Jennifer M.; Perry, Jeanette A.; Todd, Brian D.; Walsh, Allyson; Swaisgood, Ronald R. (2015)
    • Hierarchical dominance structure in reintroduced California condors: correlates, consequences, and dynamics

      Sheppard, James; Walenski, Matthew; Wallace, Michael P.; Vargas Velazco, J.J.; Porras, C.; Swaisgood, Ronald R. (2013)
      Populations of reintroduced California condors (Gymnogyps californianus) develop complex social structures and dynamics to maintain stable group cohesion, and birds that do not successfully integrate into group hierarchies have highly impaired survivability. Consequently, improved understanding of condor socioecology is needed to inform conservation management strategies…
    • High jaguar densities and large population sizes in the core habitat of the southwestern Amazon

      Tobler, Mathias W.; Carrillo-Percastegui, S.E.; Zúñiga Hartley, A.; Powell, G.V.N. (2013)
      Over 80% of the currently occupied range of the jaguar (Panthera onca) lies in the Amazon. However, few density estimates exist for this habitat. Between 2005 and 2010 we carried out six camera trap surveys at three different sites in the department of Madre de Dios in the Peruvian Amazon….
    • High-energy, high-fat lifestyle challenges an Arctic apex predator, the polar bear

      Pagano, Anthony M.; Durner, G. M.; Rode, K. D.; Atwood, T. C.; Atkinson, S. N.; Peacock, E.; Costa, D. P.; Owen, Megan A.; Williams, T. M. (2018)
      A demanding lifestyle Polar bears appear to be well adapted to the extreme conditions of their Arctic habitat. Pagano et al., however, show that the energy balance in this harsh environment is narrower than we might expect (see the Perspective by Whiteman). They monitored the behavior and metabolic rates of nine free-ranging polar bears over 2 years....
    • Highly polymorphic colour vision in a New World monkey with red facial skin, the bald uakari Cacajao calvus

      Corso, Josmael; Bowler, Mark; Heymann, Eckhard W.; Roos, Christian; Mundy, Nicholas I. (2016)
      Colour vision is highly variable in New World monkeys (NWMs). Evidence for the adaptive basis of colour vision in this group has largely centred on environmental features such as foraging benefits for differently coloured foods or predator detection, whereas selection on colour vision for sociosexual communication is an alternative hypothesis that has received little attention. The colour vision of uakaris (Cacajao) is of particular interest because these monkeys have the most dramatic red facial skin of any primate, as well as a unique fission/fusion social system and a specialist diet of seeds. Here, we investigate colour vision in a wild population of the bald uakari, C. calvus, by genotyping the X-linked opsin locus. We document the presence of a polymorphic colour vision system with an unprecedented number of functional alleles (six), including a novel allele with a predicted maximum spectral sensitivity of 555 nm. This supports the presence of strong balancing selection on different alleles at this locus. We consider different hypotheses to explain this selection. One possibility is that trichromacy functions in sexual selection, enabling females to choose high-quality males on the basis of red facial coloration. In support of this, there is some evidence that health affects facial coloration in uakaris, as well as a high prevalence of blood-borne parasitism in wild uakari populations. Alternatively, the low proportion of heterozygous female trichromats in the population may indicate selection on different dichromatic phenotypes, which might be related to cryptic food coloration. We have uncovered unexpected diversity in the last major lineage of NWMs to be assayed for colour vision, which will provide an interesting system to dissect adaptation of polymorphic trichromacy.
    • 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....
    • Historical and geographical patterns in Knemidocoptes mite infestations in Southern California birds

      Clark, Kevin B.; Rideout, Bruce; Garrett, Kimball L.; Unitt, Philip; O’Connor, Barry (2019)
      We investigated the causes of toe and foot loss and other deformities long observed in urban Brewer’s Blackbirds (Euphagus cyanocephalus) in southern California. Histopathologic evaluation showed that afflicted individuals suffered from infestations of mites compatible with Knemidokoptes spp. (scaly-leg mites). We developed a case definition based on gross lesions in confirmed cases and the scientific literature to search two large ornithological collections for specimens exhibiting these lesions. In evaluating specimens among seven species of the family Icteridae, we found 34 specimens in the two collections with lesions consistent with Knemidokoptes spp. Species afflicted included the Red-winged Blackbird (Agelaius phoeniceus; 12 of 978 specimens), Brewer’s Blackbird (10/337 specimens), Tricolored Blackbird (A. tricolor; 4/101 specimens), Brown-headed Cowbird (Molothrus ater; 4/828 specimens), and Great-tailed Grackle (Quiscalus mexicanus; 4/224 specimens). The earliest cluster of California specimens dated to 1962. Fourteen of the 34 specimens exhibiting the condition were collected since 1999. No specimens of the Yellow-headed Blackbird (Xanthocephalus xanthocephalus; 0 of 214 specimens) or Western Meadowlark (Sturnella neglecta; 0/278) were found with the condition.
    • Hologenomic adaptations underlying the evolution of sanguivory in the common vampire bat

      Mendoza, M. Lisandra Zepeda; Xiong, Zijun; Escalera-Zamudio, Marina; Runge, Anne Kathrine; Thézé, Julien; Streicker, Daniel; Frank, Hannah K.; Loza-Rubio, Elizabeth; Liu, Shengmao; Ryder, Oliver A.; et al. (2018)
      The common vampire bat (Desmodus rotundus) is one of only three obligate blood-feeding mammals. By sequencing both its genome and gut metagenome, the authors provide a holistic view of the evolutionary adaptations that underlie this unusual diet.
    • Hopping over red leg: The metamorphosis of amphibian pathology

      Pessier, Allan P. (2017)
      It wasn’t very long ago that the only disease of amphibians that students might hear about in veterinary school was “red leg syndrome,” attributed to infections with the bacterium Aeromonas hydrophila.... This would begin to change with recognition of the “Amphibian Extinction Crisis.” ....
    • Hot monkey, cold reality: surveying rainforest canopy mammals using drone-mounted thermal infrared sensors

      Kays, Roland; Sheppard, James; Mclean, Kevin; Welch, Charlie; Paunescu, Cris; Wang, Victor; Kravit, Greg; Crofoot, Meg (2018)
      Animals of the rainforest canopies are often endangered by deforestation or hunting but are difficult to survey and study because of the inaccessibility of the treetops, combined with the visual camouflage of many species. Drone-based thermal sensors have the potential to overcome these hurdles by rapidly scanning large forested areas from above, detecting and mapping wildlife based on the contrast between their warm body temperatures and the cool tree canopies....
    • Human impact erodes chimpanzee behavioral diversity

      Kühl, Hjalmar S.; Boesch, Christophe; Kulik, Lars; Haas, Fabian; Arandjelovic, Mimi; Dieguez, Paula; Bocksberger, Gaëlle; McElreath, Mary Brooke; Agbor, Anthony; Angedakin, Samuel; et al. (2019)
      Chimpanzees possess a large number of behavioral and cultural traits among non-human species. The ‘disturbance hypothesis’ predicts that human impact depletes resources and disrupts social learning processes necessary for behavioral and cultural transmission....
    • Human visual identification of individual Andean bears Tremarctos ornatus

      Van Horn, Russell C.; Zug, Becky; LaCombe, Corrin; Velez-Liendo, Ximena; Paisley, Susanna (2014)
      It is often challenging to use invasive methods of individual animal identification for population estimation, demographic analyses, and other ecological and behavioral analyses focused on individual-level processes. Recent improvements in camera traps make it possible to collect many photographic samples yet most investigators either leap from photographic sampling to assignment of individual identity without considering identification errors, or else to avoid those errors they develop computerized methods that produce accurate data with the unintended cost of excluding participation by local citizens. To assess human ability to visually identify Andean bears Tremarctos ornatus from their pelage markings we used surveys and experimental testing of 381 observers viewing photographs of 70 Andean bears of known identity. Neither observer experience nor confidence predicted their initial success rate at identifying individuals. However, after gaining experience observers were able to achieve an average success at identifying adult bears of 73.2%, and brief simple training further improved the ability of observers such that 24.8% of them achieved 100% success. Interestingly, observers who were initially more likely to falsely identify two photos of the same bear as two different bears than vice versa were likely to continue making errors and their bias became stronger, not weaker. Such biases would lead to inaccurate population estimates, invalid assessments of the bears involved in conflict situations, and underestimates of bear movements. We thus illustrate that in some systems accurate data on individual identity can be generated without the use of computerized algorithms, allowing for community engagement and citizen science. In addition, we show that when using observers to collect data on animal identity it is important to consider not only the overall frequency of observer error, but also observer biases and error types, which are rarely reported in field studies.
    • Human-Giraffe Interactions: Characterizing Poaching and Use of Parts as a Threat to Giraffe in Northern Kenya

      Ruppert, Kirstie (The University of Maine, 2020)
      Giraffe (Giraffe spp.) are iconic wildlife species to Africa, yet relatively little conservation funding and research have been directed at protection of giraffe in the wild. A growing number of national governments and conservation organizations are implementing management strategies to address the threats that giraffe face. To inform these plans, there is a need for social science that examines the human pressures associated with decline of giraffe populations, including poaching and the use of giraffe parts. As the large majority of reticulated giraffe (Giraffa reticulata) range occurs outside formally protected areas, conservation plans must be made with pastoralist communities and other actors in northern Kenya where the land is shared between people, their livestock, and wildlife. The research presented in this dissertation was conducted as part of a community-based program focused on reticulated giraffe, called the Twiga Walinzi Initiative (“Giraffe Guards” in Swahili), and represents the first quantitative study on the human dimensions of giraffe conservation. Goals of the research project were to examine key cognitions to human-giraffe interactions (i.e. attitudes, beliefs, perceptions), assess relationships between certain cognitions within areas that adopt a community-based conservation approach, and understand the extent and drivers of giraffe meat and part usage. Face-to-face interviews were conducted at two study sites over survey periods in 2016/17 (n=579) and 2019 (n=680). Results from these studies provide insights to how pastoralist communities view and act toward local giraffe. Factors that significantly influenced support for giraffe conservation differed between study sites, suggesting that local context is important to shaping human-giraffe interactions (Chapter 2). For instance, perceived benefits had stronger influence on normative belief in communities more recently connected with wildlife-based tourism. The linkages between perceived benefits, attitudes, and behaviors were further explored by assessing the relationships between these concepts within a community-based conservation setting (Chapter 3). Findings suggest a positive association between perceived benefits and attitudes toward giraffe, but there was less evidence that perceptions of wildlife-related benefits influenced use of giraffe meat/parts. As human behavior is of central interest to conservation, we also assessed levels of giraffe meat consumption (Chapter 4) and determinants of intention to consume giraffe meat (Chapter 5). Specialized questioning techniques were utilized to estimate prevalence of giraffe meat consumption preceding the two surveys. Estimated prevalence of giraffe meat consumption declined after establishment of the Twiga Walinzi. Perceived behavioral control had stronger relative influence than attitudes and subjective norms on future intention to consume
    • Human–wildlife conflicts and the need to include coexistence

      Frank, Beatrice; Glikman, Jenny A.; Frank, Beatrice; Glikman, Jenny A.; Marchini, Silvio (Cambridge University Press, 2019)
    • Human–wildlife interactions: Multifaceted approaches for turning conflict into coexistence

      Glikman, Jenny A.; Frank, Beatrice; Marchini, Silvio; Frank, Beatrice; Glikman, Jenny A.; Marchini, Silvio (Cambridge University Press, 2019)
    • Human–Wildlife Interactions: Turning Conflict into Coexistence

      Frank, Beatrice; Glikman, Jenny A.; Marchini, Silvio; Frank, Beatrice; Glikman, Jenny A.; Marchini, Silvio (Cambridge University Press, 2019)