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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. Source

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. Source

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. Source

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. Source

Pimm S.L.,Duke University | Alibhai S.,SAS Institute | Bergl R.,North Carolina Zoological Park | Dehgan A.,Conservation X Labs | And 5 more authors.
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. Copyright © 2015 Elsevier Ltd. All rights reserved. Source

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