Thalmann O.,Max Planck Institute for Evolutionary Anthropology |
Thalmann O.,University of Turku |
Wegmann D.,University of California at Los Angeles |
Spitzner M.,Max Planck Institute for Evolutionary Anthropology |
And 5 more authors.
BMC Evolutionary Biology | Year: 2011
Abstract. Background: Today many large mammals live in small, fragmented populations, but it is often unclear whether this subdivision is the result of long-term or recent events. Demographic modeling using genetic data can estimate changes in long-term population sizes while temporal sampling provides a way to compare genetic variation present today with that sampled in the past. In order to better understand the dynamics associated with the divergences of great ape populations, these analytical approaches were applied to western gorillas (Gorilla gorilla) and in particular to the isolated and Critically Endangered Cross River gorilla subspecies (G. g. diehli). Results: We used microsatellite genotypes from museum specimens and contemporary samples of Cross River gorillas to infer both the long-term and recent population history. We find that Cross River gorillas diverged from the ancestral western gorilla population ∼17,800 years ago (95% HDI: 760, 63,245 years). However, gene flow ceased only ∼420 years ago (95% HDI: 200, 16,256 years), followed by a bottleneck beginning ∼320 years ago (95% HDI: 200, 2,825 years) that caused a 60-fold decrease in the effective population size of Cross River gorillas. Direct comparison of heterozygosity estimates from museum and contemporary samples suggests a loss of genetic variation over the last 100 years. Conclusions: The composite history of western gorillas could plausibly be explained by climatic oscillations inducing environmental changes in western equatorial Africa that would have allowed gorilla populations to expand over time but ultimately isolate the Cross River gorillas, which thereafter exhibited a dramatic population size reduction. The recent decrease in the Cross River population is accordingly most likely attributable to increasing anthropogenic pressure over the last several hundred years. Isolation of diverging populations with prolonged concomitant gene flow, but not secondary admixture, appears to be a typical characteristic of the population histories of African great apes, including gorillas, chimpanzees and bonobos. © 2011 Thalmann et al; licensee BioMed Central Ltd.
Bergl R.A.,North Carolina Zoological Park |
Warren Y.,Wildlife Conservation Society |
Nicholas A.,Wildlife Conservation Society |
Dunn A.,Wildlife Conservation Society |
And 4 more authors.
ORYX | Year: 2012
Habitat loss and fragmentation are among the major threats to wildlife populations in tropical forests. Loss of habitat reduces the carrying capacity of the landscape and fragmentation disrupts biological processes and exposes wildlife populations to the effects of small population size, such as reduction of genetic diversity and increased impact of demographic stochasticity. The Critically Endangered Cross River gorilla Gorilla gorilla diehli is threatened in particular by habitat disturbance because its population is small and it lives in an area where high human population density results in intense exploitation of natural resources. We used remotely-sensed data to assess the extent and distribution of gorilla habitat in the Cross River region and delineated potential dispersal corridors. Our analysis revealed > 8,000 km 2 of tropical forest in the study region, 2,500 km 2 of which is in or adjacent to areas occupied by gorillas. We surveyed 12 areas of forest identified as potential gorilla habitat, 10 of which yielded new records of gorillas. The new records expand the known range of the Cross River gorilla by > 50%, and support genetic analyses that suggest greater connectivity of the population than previously assumed. These findings demonstrate that considerable connected forest habitat remains and that the area could potentially support a much larger gorilla population if anthropogenic pressures such as hunting could be reduced. © 2011 Fauna & Flora International.
PubMed | SAS Institute, Conservation X Labs, California Academy of Sciences, North Carolina State University and 4 more.
Type: Journal Article | Journal: Trends in ecology & evolution | Year: 2015
Technologies to identify individual animals, follow their movements, identify and locate animal and plant species, and assess the status of their habitats remotely have become better, faster, and cheaper as threats to the survival of species are increasing. New technologies alone do not save species, and new data create new problems. For example, improving technologies alone cannot prevent poaching: solutions require providing appropriate tools to the right people. Habitat loss is another driver: the challenge here is to connect existing sophisticated remote sensing with species occurrence data to predict where species remain. Other challenges include assembling a wider public to crowdsource data, managing the massive quantities of data generated, and developing solutions to rapidly emerging threats.
Hasenjager M.J.,Michigan State University |
Bergl R.A.,North Carolina Zoological Park
Zoo Biology | Year: 2015
Repetitive movement patterns are commonly observed in zoo elephants. The extent to which these behaviors constitute a welfare concern varies, as their expression ranges from stereotypies to potentially beneficial anticipatory behaviors. Nevertheless, their occurrence in zoo animals is often viewed negatively. To better identify conditions that prompt their performance, observations were conducted on six African elephants (Loxodonta africana) at the North Carolina Zoo. Individuals spent most of their time engaged in feeding, locomotion, resting, and repetitive behavior. Both generalized estimating equation and zero-inflated negative binomial models were used to identify factors associated with increased rates of repetitive behavior. Time of day in conjunction with location on- or off-exhibit best explained patterns of repetitive behavior. Repetitive behaviors occurred at a lower rate in the morning when on-exhibit, as compared to afternoons on-exhibit or at any time of day off-exhibit. Increased repetitive behavior rates observed on-exhibit in the afternoon prior to the evening transfer and feeding were possibly anticipatory responses towards those events. In contrast, consistently elevated frequencies of repetitive behavior off-exhibit at all times of day could be related to differences in exhibit complexity between off-exhibit and on-exhibit areas, as well as a lack of additional foraging opportunities. Our study contributes valuable information on captive elephant behavior and represents a good example of how behavioral research can be employed to improve management of zoo animals. © 2015 Wiley Periodicals, Inc.
Spear S.F.,The Orianne Society |
Spear S.F.,University of Idaho |
Groves J.D.,North Carolina Zoological Park |
Williams L.A.,North Carolina Wildlife Resources Commission |
Waits L.P.,University of Idaho
Biological Conservation | Year: 2015
Isolation of environmental DNA (eDNA) is becoming a valuable tool for detecting presence of rare or secretive aquatic species. The recent use of quantitative PCR (qPCR) with eDNA sampling presents the possibility of using this method to infer population abundance and status. This approach would be especially useful for species such as the Eastern hellbender (Cryptobranchus alleganiensis alleganiensis), a declining, secretive, aquatic salamander that requires intense field survey effort to study. In 2012, we conducted eDNA sampling at sites across the range of the species in North Carolina. Our objectives were to assess presence across 61 sites, test for a correlation of abundance and biomass with eDNA estimates at a subset of 23 sites, and sample at multiple spatial and temporal scales in three river systems. Overall, we detected hellbender eDNA at 33 sites, including all sites with 2012 hellbender records, 71% of all recent or historic sites with hellbender presence, and at nine sites that lack species occurrence records. We did not find a correlation between eDNA estimates and field survey counts of individuals or biomass. We detected a strong temporal increase in eDNA during the September breeding period, but no consistent evidence of a spatial relationship with eDNA. Overall, our results demonstrate the efficacy of eDNA for detecting hellbender populations. Furthermore, the potential utility of qPCR to assess population status in hellbenders requires further study and testing, although it may be promising for determining population reproductive status. © 2014 Elsevier Ltd.
Stringer E.M.,North Carolina State University |
De Voe R.S.,North Carolina Zoological Park |
Loomis M.R.,North Carolina Zoological Park
Journal of Zoo and Wildlife Medicine | Year: 2011
Two adult female elf owls (Micrathene whitneyi) were treated with leuprolide acetate depot injections to prevent egg laying. The birds were treated for several years without complications. Several years into the treatment regimen, both birds died immediately after receiving an injection of leuprolide acetate. Remaining drug was analyzed, revealing 95.7% potency. We suspect that either an immediate Type 1 hypersensitivity reaction occurred or a contaminant was present, resulting in the fatalities of these elf owls. No reports of anaphylaxis to leuprolide acetate in birds were identified in the literature. Clinicians should be aware of the possibility of anaphylaxis when administering this medication to avian patients. © 2011 American Association of Zoo Veterinarians.
Dombrowski D.S.,North Carolina State University |
De Voe R.S.,North Carolina Zoological Park |
Lewbart G.A.,North Carolina State University
Zoo Biology | Year: 2013
This study investigated the use of two anesthetic agents, isoflurane and carbon dioxide, in Chilean rose tarantulas (Grammostola rosea). We compared the onset, duration of anesthesia, and recovery time with both gases, and made observations regarding the effects of the anesthetic protocols. Subjectively, episodes for the isoflurane animals were uneventful. The spiders were calm throughout and did not respond adversely to gas exposure. Conversely, animals anesthetized with carbon dioxide experienced violent inductions and recoveries; the tarantulas appeared agitated when the carbon dioxide flow began. Seizure-like activity and defecation would frequently be noted prior to induction with carbon dioxide. Neither isoflurane nor carbon dioxide seemed to have any clinically apparent short- or long-term impact. The animals were all normal for at least 1-year postexperiment. Future studies should focus on defining the impact, if any, that these anesthetic agents have on the health of invertebrate species. © 2012 Wiley Periodicals, Inc.
Cronin D.T.,Drexel University |
Libalah M.B.,University of Yaounde I |
Bergl R.A.,North Carolina Zoological Park |
Hearn G.W.,Drexel University
Arctic, Antarctic, and Alpine Research | Year: 2014
Mount Cameroon (4095 m), the highest peak and only active volcano in West Africa, is located in the center of the Gulf of Guinea Pleistocene refugium. The associated forests and highlands along the southern Nigerian-Cameroon border and on the island of Bioko, known as the Biafran forests and highlands, are important formations of the Cameroon Volcanic Line owing to their wide elevational range, and on Mount Cameroon, a continuous gradient of unbroken vegetation from sea level to over 4000 m. The montane zones in the region begin 800 m above sea level forming the critically endangered Mount Cameroon and Bioko Montane Forests ecoregion. The broad elevational gradient of the region has resulted in high habitat diversity, leading the region to be a center for species endemism and richness across many taxa. Some of the densest human populations in Africa also occur in this region, putting intense pressure on the forests and highlands mostly due to overexploitation and habitat loss. The governments of Nigeria, Cameroon, and Equatorial Guinea have designated protected areas in the region, but coverage is inadequate, especially for the rare montane ecosystems and endemic taxa. More importantly, protected areas are often not accompanied by effective management and regulatory enforcement. We recommend improved law enforcement and an expansion of the protected area network, as well as stronger commitments of institutional, financial, and technical support from governments and non-governmental organizations, in order to move conservation in the region in a positive direction. Without significant and immediate conservation progress, increasing anthropogenic pressure and systemic ineffectiveness of protected area management represent major concerns for the future of this important area. © 2014 Regents of the University of Colorado.
Williams L.A.,North Carolina Wildlife Resources Commission |
Groves J.D.,North Carolina Zoological Park
Herpetological Conservation and Biology | Year: 2014
Due to recent documented declines of Eastern Hellbender (Cryptobranchus a. alleganiensis) populations, in 2008–2012 we surveyed both wild-caught and captive hellbenders in Western North Carolina for the prevalence of a common amphibian pathogen, Batrachochytrium dendrobatidis (Bd). We sampled 165 wild and 15 captive animals of North Carolina origin. We collected morphometric data from hellbenders, noted the presence of any physical anomalies or injuries, and recorded water temperature and site elevation. We found Bd to be widespread in Western North Carolina waterways and in all river basins and sub-basins sampled. Batrachochytrium dendrobatidis prevalence was 27.9% for wild-caught animals and 26.7% for captives. Adult female hellbenders had a significantly higher prevalence of Bd (38.8%) than adult males (19.7% P = 0.0207). All age classes tested positive for Bd, including gilled larvae. From examining hellbender body condition, we found no physical evidence of acute infection or compromised immunity due to disease. There was no significant relationship between the presence of Bd and physical injuries or anomalies (P = 0.1196). We also found that water temperature (P = 0.5038) and elevation (P = 0.5100) were not significant for predicting the presence of Bd. Ours is the first report of Bd for Eastern Hellbenders in North Carolina. Although it does not appear that hellbenders in North Carolina are in crisis due to disease, future monitoring and surveillance efforts within populations should continue, particularly across a variety of habitat disturbance regimes. © 2014. Lori Williams. All rights reserved.
Imong I.,Max Planck Institute for Evolutionary Anthropology |
Imong I.,Wildlife Conservation Society |
Robbins M.M.,Max Planck Institute for Evolutionary Anthropology |
Mundry R.,Max Planck Institute for Evolutionary Anthropology |
And 2 more authors.
Animal Conservation | Year: 2014
The geographic range of many species has been reduced and fragmented by human impact, and ever more species live in human-dominated landscapes where they are confined to small and often suboptimal refuge areas. A detailed understanding of the causation of species' persistence and disappearance is crucial to inform management of which interventions are likely to be most effective. Yet this information is often not available to decision makers and may, in the worst case, lead to erroneous management decisions. To clarify whether Cross River gorilla Gorilla gorilla diehli (CRG) occurrence is restricted due to ecological constraints or human disturbance, we collected extensive field data on food availability, habitat structure, human activity and wildlife abundance, which we related to CRG occurrence. We also related spatial variation in hunting pressure to human density, household forest use and topography. Our results clearly show that CRG are currently confined to refuge areas because of ongoing detrimental human activities and not because of lack of food resources. Current hunting pressure is driven by human population pressure, accessibility and socioeconomic conditions influencing household dependence on forest. A substantial amount of ecologically suitable but currently unoccupied habitat could potentially carry a much larger CRG population. Conservation management should therefore focus on reducing hunting and disturbance of CRG. In contrast, ecological restoration would not improve CRG living conditions. Our field and analytical approach is widely applicable to the rapidly increasing number of species inhabiting heavily human-influenced landscapes for identifying appropriate management interventions for their protection. © 2013 The Zoological Society of London.