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Gorilla Population (gorilla + population)
Selected AbstractsAn analysis of breeding results for hand-reared Gorillas Gorilla gorilla born over a 25 year period in the European Endangered Species Programme (EEP) populationINTERNATIONAL ZOO YEARBOOK, Issue 1 2010Ma T. ABELLÓ In December 2004, a questionnaire was sent to 44 institutions that maintained Gorillas Gorilla gorilla. Twenty-six institutions replied (59% response rate) providing information about 91 hand-reared Gorillas in the European Endangered Species Programme (EEP) population. Using other sources, such as the international studbook and EEP reports, data on 63.54 (,.,) Gorillas that had been hand reared between 1980 and 2004 were analysed. Over this period, 23 (43%) ,, and 15 (24%) ,, bred successfully. However, when the numbers used to make the analyses were corrected by removing Gorillas (1) that had not yet reached full sexual maturity (>12 years for ,, and >10 years for ,,) and (2) were not maintained in breeding groups, and including three ,, that bred before they were 10 years of age, the percentages for breeding success are 65% for ,, and 61% for ,,. These results demonstrate that hand-reared individuals contribute to the increase in the EEP Gorilla population observed over the past 25 years. [source] Gastrointestinal Bacterial Transmission among Humans, Mountain Gorillas, and Livestock in Bwindi Impenetrable National Park, UgandaCONSERVATION BIOLOGY, Issue 6 2008INNOCENT B. RWEGO ecología de enfermedades; Escherichia coli; primates; salud del ecosistema; zoonosis Abstract:,Habitat overlap can increase the risks of anthroponotic and zoonotic pathogen transmission between humans, livestock, and wild apes. We collected Escherichia coli bacteria from humans, livestock, and mountain gorillas (Gorilla gorilla beringei) in Bwindi Impenetrable National Park, Uganda, from May to August 2005 to examine whether habitat overlap influences rates and patterns of pathogen transmission between humans and apes and whether livestock might facilitate transmission. We genotyped 496 E. coli isolates with repetitive extragenic palindromic polymerase chain reaction fingerprinting and measured susceptibility to 11 antibiotics with the disc-diffusion method. We conducted population genetic analyses to examine genetic differences among populations of bacteria from different hosts and locations. Gorilla populations that overlapped in their use of habitat at high rates with people and livestock harbored E. coli that were genetically similar to E. coli from those people and livestock, whereas E. coli from gorillas that did not overlap in their use of habitats with people and livestock were more distantly related to human or livestock bacteria. Thirty-five percent of isolates from humans, 27% of isolates from livestock, and 17% of isolates from gorillas were clinically resistant to at least one antibiotic used by local people, and the proportion of individual gorillas harboring resistant isolates declined across populations in proportion to decreasing degrees of habitat overlap with humans. These patterns of genetic similarity and antibiotic resistance among E. coli from populations of apes, humans, and livestock indicate that habitat overlap between species affects the dynamics of gastrointestinal bacterial transmission, perhaps through domestic animal intermediates and the physical environment. Limiting such transmission would benefit human and domestic animal health and ape conservation. Resumen:,El traslape de hábitats puede incrementar los riesgos de transmisión de patógenos antroponótica y zoonótica entre humanos, ganado y simios silvestres. Recolectamos bacterias Escherichia coli de humanos, ganado y gorilas de montaña (Gorilla gorilla beringei) en el Parque Nacional Bwindi Impenetrable, Uganda, de mayo a agosto 2005 para examinar sí el traslape de hábitat influye en las tasas y patrones de transmisión de patógenos entre humanos y simios y sí el ganado facilita esa transmisión. Determinamos el genotipo de 496 aislados de E. coli con marcaje de reacción en cadena de polimerasa palindrómica extragénica (rep-PCR) y medimos la susceptibilidad a 11 antibióticos con el método de difusión de disco. Realizamos análisis de genética poblacional para examinar las diferencias genéticas entre poblaciones de bacterias de huéspedes y localidades diferentes. Las poblaciones de gorilas con alto grado de traslape en el uso de hábitat con humanos y ganado presentaron E. coli genéticamente similar a E. coli de humanos y ganado, mientras que E. coli de gorilas sin traslape en el uso hábitat con humanos y ganado tuvo relación lejana con las bacterias de humanos y ganado. Treinta y cinco porciento de los aislados de humanos, 27% de los aislados de ganado y 17% de los aislados de gorilas fueron clínicamente resistentes a por lo menos un antibiótico utilizado por habitantes locales, y la proporción de gorilas individuales con presencia de aislados resistentes declinó en las poblaciones proporcionalmente con la disminución en el grado de traslape con humanos. Estos de patrones de similitud genética y resistencia a antibióticos entre E. coli de poblaciones de simios, humanos y ganado indican que el traslape de hábitat entre especies afecta la dinámica de transmisión de bacterias gastrointestinales, probablemente a través de animales domésticos intermediarios y el ambiente físico. La limitación de esa transmisión beneficiaría a la salud de humanos y animales domésticos y a la conservación de simios. [source] Censusing the mountain gorillas in the Virunga Volcanoes: complete sweep method versus monitoringAFRICAN JOURNAL OF ECOLOGY, Issue 3 2010Maryke Gray Abstract The mountain gorillas (Gorilla beringei beringei) of the Virunga Volcanoes Range of Rwanda, Uganda, and the Democratic Republic of Congo are one of the most endangered ape populations in the world. Following a dramatic decline during the 1960s, and relative stability in the 1970s, the population steadily increased during the 1980s. Due to political instability and war, a complete census had not been conducted since 1989. Here we compare the results of a complete census using the ,sweep method' conducted in 2003 with those from a monitoring program, to estimate the size and distribution of the gorilla population. A total of 360 gorillas were counted from census measurements and known habituated groups. Based on quantitative assessments of the census accuracy, we calculated that an additional 20 gorillas were not counted, leading to an estimated population of 380 individuals, and a 1.15% annual growth rate since 1989. The Ranger Based Monitoring programme yielded similar results. The encouraging results must be viewed with caution, however, because the growth was concentrated almost entirely in one section of the Virungas. Additionally, the distribution of gorilla groups was negatively correlated with the frequency of human disturbances, which highlights the need to continue strengthening conservation efforts. Résumé Les gorilles de montagne Gorilla gorilla beringei de l'aire de répartition des Volcans Virunga, au Rwanda, en Ouganda et en République Démocratique du Congo, sont une des populations de grands singes les plus menacées du monde. Après un déclin dramatique dans le courant des années 1960, et une stabilité relative dans les années 1970, la population s'est fermement reconstituée au cours des années 1980. Mais en raison de l'instabilité politique et de la guerre, il n'y avait plus eu de recensement total depuis 1989. Nous comparons ici les résultats d'un recensement complet effectué en 2003 par la méthode du balayage topologique (sweep method) avec ceux d'un programme de suivi, afin d'estimer la taille et la distribution de la population de gorilles. Nous avons dénombré un total de 360 gorilles en reprenant les chiffres du recensement et ceux des groupes habitués connus. En nous basant sur l'évaluation quantitative de la précision du recensement, nous avons calculé que 20 gorilles supplémentaires n'avaient pas été comptés, ce qui porte l'estimation à 380 individus et signifie un taux de croissance annuel de 1,15% depuis 1989. Le Programme de Suivi basé sur les gardes a obtenu des résultats comparables. Pourtant, ces résultats encourageants doivent être interprétés avec prudence étant donné que la croissance s'est presque entièrement concentrée sur une seule section des Virunga. De plus, la distribution des groupes de gorilles était négativement liée à la fréquence des perturbations humaines, ce qui souligne la nécessité de poursuivre le renforcement des mesures de conservation. [source] Physical maturation, life-history classes and age estimates of free-ranging western gorillas,insights from Mbeli Bai, Republic of CongoAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2009Thomas Breuer Abstract Physical maturation and life-history parameters are seen as evolutionary adaptations to different ecological and social conditions. Comparison of life-history patterns of closely related species living in diverse environments helps to evaluate the validity of these assumptions but empirical data are lacking. The two gorilla species exhibit substantial differences in their environment, which allows investigation into the role of increased frugivory in shaping western gorilla life histories. We present behavioral and morphological data on western gorilla physical maturation and life-history parameters from a 12.5-year study at Mbeli Bai, a forest clearing in the Nouabalé-Ndoki National Park in northern Congo. We assign photographs of known individuals to different life-history classes and propose new age boundaries for life-history classes in western gorillas, which can be used and tested at other western gorilla research sites. Our results show that western gorillas are weaned at a later age compared with mountain gorillas and indicate slower physical maturation of immatures. These findings support the risk-aversion hypothesis for more frugivorous species. However, our methods need to be applied and tested with other gorilla populations. The slow life histories of western gorillas could have major consequences for social structure, mortality patterns and population growth rates that will affect recovery from population crashes of this critically endangered species. We emphasize that long-term studies can provide crucial demographic and life-history data that improve our understanding of life-history evolution and adaptation and help to refine conservation strategies. Am. J. Primatol. 71:106,119, 2009. © 2008 Wiley-Liss, Inc. [source] | ||||||||||