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Schwitzer N.,Justus Liebig University | Clough D.,Abteilung Verhaltensokologie y Soziobiologie Anthropologie | Zahner H.,Justus Liebig University | Kaumanns W.,Eschenweg 5 | And 2 more authors.
Endangered Species Research | Year: 2010

The parasite burden of an animal population has frequently been used as an indicator of the stress level to which the population is exposed. Primates inhabiting small forest fragments are more likely to experience human contact, reduced food availability and restricted ranging-any or all of which may contribute to a higher parasite prevalence-than populations inhabiting intact primary forest. Recent and ongoing human exploitation of otherwise intact forest may also affect disease burden and parasite transmission in primates. The parasites of blue-eyed black lemurs Eulemur flavifrons have not as yet been subject to scientific research. This paper describes the various parasites found in E. flavifrons and shows parasite prevalence in lemur groups living in differently degraded fragments of the Ankarafa Forest in Sahamalaza National Park, northwest Madagascar. We analysed 166 faecal samples of E. flavifrons inhabiting primary forest and 168 from groups inhabiting secondary forest. In addition, faecal samples and ectoparasites were collected from 18 immobilised lemurs. Forty-three (12.9%) samples contained parasite eggs (Lemuricola spp. and Callistoura spp.) or oocysts. Ten (55.6%) of the 18 samples from immobilised lemurs contained adult Lemuricola spp. Parasite prevalence was significantly higher in secondary than in primary forest, at 7.9 and 4.8% of all positive samples, respectively. Prevalence was high when compared to other studies on parasite load in wild lemurs, suggesting that in our survey area, E. flavifrons were generally under pressure, possibly due to the high degree of fragmentation and degradation of the remaining forest habitat. © Inter-Research 2010. Source

Schwitzer C.,Bristol Conservation and Science Foundation | Glatt L.,Bristol Conservation and Science Foundation | Nekaris K.A.-I.,Oxford Brookes University | Ganzhorn J.U.,University of Hamburg
Endangered Species Research | Year: 2011

Original habitat of animal species is being destroyed at an accelerating rate. This is usually associated with an alteration of the remaining habitat, which becomes degraded and/or fragmented. In many regions, forests are cleared to make way for plantations or other agricultural use, and animal species are forced to coexist with humans. In some countries, forests are in the process of being restored for wildlife. As even long-established and well-protected areas typically comprise mosaics of habitats with different degrees of degradation, the future conservation of many species will depend on the capacity of such altered habitats to support their populations. During the last 15 yr, more and more studies have addressed the way that different species respond to the human-induced change of their habitats. These responses are varied, and range from population decline to adaptation and development of new behavioural strategies. Whereas some species rely heavily on intact primary forests, others can adapt to secondary forests and forest-agriculture mosaics. Habitat change has been shown to affect many aspects of the ecology and behaviour of animals. Changes in dietary composition and diversity, population density, group size and adult sex ratio in groups are some examples. This Theme Section of Endangered Species Research collates a number of case studies on how animals, and particularly primates, respond to the alteration of their habitat. © Inter-Research 2011. Source

Taylor L.A.,Bristol Conservation and Science Foundation | Taylor L.A.,University of Bristol | Kaiser T.M.,University of Hamburg | Schwitzer C.,Bristol Conservation and Science Foundation | And 4 more authors.
PLoS ONE | Year: 2013

Extant rhinos are the largest extant herbivores exhibiting dietary specialisations for both browse and grass. However, the adaptive value of the wear-induced tooth morphology in rhinos has not been widely studied, and data on individual cusp and tooth positions have rarely been published. We evaluated upper cheek dentition of browsing Diceros bicornis and Rhinoceros sondaicus, mixed-feeding R. unicornis and grazing Ceratotherium simum using an extended mesowear method adapted for rhinos. We included single cusp scoring (EM(R)-S) to investigate inter-cusp and inter-tooth wear patterns. In accordance with previous reports, general mesowear patterns in D. bicornis and R. sondaicus were attrition-dominated and C. simum abrasion-dominated, reflecting their respective diets. Mesowear patterns for R. unicornis were more attrition-dominated than anticipated by the grass-dominated diet, which may indicate a low intake of environmental abrasives. EM(R)-S increased differentiation power compared to classical mesowear, with significant inter-cusp and inter-tooth differences detected. In D. bicornis, the anterior cusp was consistently more abrasion-dominated than the posterior. Wear differences in cusp position may relate to morphological adaptations to dietary regimes. Heterogeneous occlusal surfaces may facilitate the comminution of heterogeneous browse, whereas uniform, broad grinding surfaces may enhance the comminution of physically more homogeneous grass. A negative tooth wear gradient was found in D. bicornis, R. sondaicus and R. unicornis, with wear patterns becoming less abrasion-dominated from premolars to molars. No such gradients were evident in C. simum which displayed a uniform wear pattern. In browsers, premolars may be exposed to higher relative grit loads, which may result in the development of wear gradients. The second premolar may also have a role in food cropping. In grazers, high absolute amounts of ingested abrasives may override other signals, leading to a uniform wear pattern and dental function along the tooth row, which could relate to the observed evolution towards homodonty. © 2013 Taylor et al. Source

Johanna Rode E.,Bristol Conservation and Science Foundation | Johanna Rode E.,Oxford Brookes University | Anne-Isola Nekaris K.,Oxford Brookes University | Markolf M.,German Primate Center | And 5 more authors.
Contributions to Zoology | Year: 2013

Shelters such as leaf nests, tree holes or vegetation tangles play a crucial role in the life of many nocturnal mammals. While information about characteristics and availability of these resources may help in conservation planning, nest use gives an indication about a species' social organisation. The northern giant mouse lemur (Mirza zaza) is threatened by habitat loss within its restricted range. Our aim was to examine nest site preferences of M. zaza and to explore the species' social organisation by examining sleeping site aggregation size and genetic relatedness within and between such aggregations. In the Ankarafa Forest inside Sahamalaza - Iles Radama National Park, northwestern Madagascar, we radio-tagged five male and three female M. zaza and followed them for 2.5 months during the dry season. We identified sleeping trees and observed animals during emergence in the evening and return in the morning. We compared sleeping trees and microhabitats around nest sites to trees and habitat used during nightly activity and to random sites. We found that nests were well covered by canopy, even during the dry season, and were located near the tree trunk a few meters below the tree top. Nest sites were characterised by large (> 30 cm DBH) and tall trees (>16 m) with many lianas. Up to four animals shared one to three group-exclusive nests for up to 50 days. Two of the nest groups included two and three males with fully developed testes. Relatedness data revealed that the adult males sharing nests were either unrelated or closely related. These data suggest that M. zaza is sleeping in social nest groups including multiple males, which is unusual among nocturnal strepsirrhines. Apart from protecting suitable sleeping trees and discouraging selective logging of large trees, we recommend conducting further studies on the species' social organisation throughout an entire season. Source

Hawlitschek O.,Zoologische Staatssammlung Munich | Bruckmann B.,Zoologische Staatssammlung Munich | Berger J.,Zoologische Staatssammlung Munich | Green K.,Bristol Conservation and Science Foundation | Glaw F.,Zoologische Staatssammlung Munich
ZooKeys | Year: 2011

We studied the non-marine reptile and amphibian species of the volcanic Comoro archipelago in the Western Indian Ocean, a poorly known island herpetofauna comprising numerous microendemic species of potentially high extinction risk and widespread, non-endemic and often invasive taxa. According to our data, the Comoro islands are inhabited by two amphibian species and at least 28 species of reptiles although ongoing genetic studies and unconfirmed historical records suggest an even higher species diversity. 14 of the 28 currently recognized species of terrestrial reptiles (50%) and the two amphibians are endemic to a single island or to the Comoro archipelago. Te majority of species are most abundant at low elevation. However, a few endemic species, like the gekkonid lizards Paroedura sanctijohannis and Phelsuma nigristriata, are more common in or even confined to higher altitudes. We created habitat maps from remotely sensed data in combination with detailed species distribution maps produced using comprehensive data from field surveys between 2000 and 2010, literature, and historical locality records based on specimens in zoological collections. Using these data, we assessed the conservation status of the endemic terrestrial reptiles and amphibians according to the IUCN Red List criteria. Our results show that although little area of natural forest remains on the Comoros, many species are abundant in degraded forest or plantations. Competition and predation by invasive species appears to be the most important threat factor for the endemic herpetofauna, together with habitat degradation and destruction, which further favors invasive species. We propose the status Endangered for three species, Vulnerable for one species, Near Treatened for six species, Least Concern for four and Data Deficient for two species. Te endemic subspecies Oplurus cuvieri comorensis is proposed for the status Critically Endangered. Based on the results of this study, seven areas of importance for reptile and amphibian conservation on the Comoros are identified. Tis study shows how remote sensing data can contribute to increasing accuracy and objectiveness of conservation assessments. © Oliver Hawlitschek et al. Source

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