@article {336, title = {Redescription of the tadpole of Phlyctimantis boulengeri Perret, 1986 (Anura, Hyperoliidae) with preliminary comments on the biology of the species}, journal = {Alytes (Paris)}, volume = {18}, number = {3-4}, year = {2001}, month = {January, 2001}, pages = {178-186}, abstract = {We redescribe the tadpole of Phlyctimantis boulengeri Perret, 1986 based on specimens from Tai National Park, Ivory Coast. The tadpoles resemble very much those of the genus Kassina. We found no hints for arboreal spawning, as described by Guibe and Lamotte (1958) for this species. Eggs were laid singly below the surface of water. Adults showed a conspicuous defence behaviour.}, url = {://PREV200100217166}, author = {R{\"o}del, Mark-Oliver and Ernst, Raffael} } @article {339, title = {Death-feigning in some West African frogs}, journal = {Salamandra}, volume = {36}, number = {2}, year = {2000}, month = {30 Juni, 2000}, pages = {125-130}, abstract = {

We report on death-feigning behaviour in Chiromantis rufescens, Kassina lamottei, K. cochranae, Leptopelis hyloides, L. occidentalis, and L. macrotis from Tai National Park, Ivory Coast.

}, url = {://PREV200100333602}, author = {R{\"o}del, Mark-Oliver and Ernst, Raffael and Leistner, Gerhard and Fahr, Jakob} } @article {343, title = {First record of the genus Acanthixalus Laurent, 1944 from the upper Guinean rain forest, West Africa, with the description of a new species}, journal = {Journal of Herpetology}, volume = {37}, number = {1}, year = {2003}, month = {March 2003}, pages = {43-52}, abstract = {We describe a new species of Acanthixalus from southwestern Ivory Coast Acanthixalus sonjae sp. nov. differs from the Central African Acanthixalus spinosus genetically by 4.6\% in the investigated 16S rRNA. Morphologically adult frogs are very similar to A. spinosus. Male A. sonjae have wider heads and probably smaller gular glands than A. spinosus. Tadpoles of A. sonjae differ by much longer tails. Acanthixalus sonjae males are apparently mute. The new species is semiaquatic and lives in large waterfilled cavities of trees in secondary and primary rain forest Tadpoles complete metamorphosis in three months. They are at least partly carnivorous.}, url = {://PREV200300584872}, author = {R{\"o}del, Mark-Oliver and Kosuch, Joachim and Veith, Michael and Ernst, Raffael} } @article {342, title = {Amphibian diversity and diversity changes in West Africa: global, regional, or local causes?}, year = {2003}, keywords = {diversity, Phrynobatrachus, West Africa}, url = {file://localhost/Users/breda/Desktop/Literature/R/Ro\%CC\%88del-Amphibien\%20Westafrikas.pdf}, author = {R{\"o}del, Mark-Oliver and J. Kosuch and Ernst, Raffael and V. Rudolf and G. Schorr and C. Harbig and S. Frohschammer and G. Leistner and M. Wegmann and P.J. Adeba and G.N. Kouam{\'e} and A.A. Cudjoe and K.E. Linsenmair and Veith, Michael} } @article {344, title = {The tadpole of Ptychadena aequiplicata (Werner, 1898) with the description of a new reproductive mode for the genus (Amphibia, Anura, Ranidae)}, journal = {Alytes (Paris)}, volume = {20}, number = {1-2}, year = {2002}, month = {December}, pages = {1-12}, abstract = {

We describe the tadpole of Ptychadena aequiplicata (Werner, 1898) based on specimens from Tai National Park, Ivory Coast. Compared to other tadpoles of the genus it is unique by its bicoloured body, posterior part lighter than anterior one. Ptychadena aequiplicata is restricted to closed forest habitats. It has a reproductive behaviour unique to the genus. Clutches of numerous females were communally deposited on the forest floor, between leaves and small plants. Spawning sites were always situated at the edges of dried up ponds. Pre-hatching time was variable. Tadpoles still hatched two weeks after oviposition. In some specimens development continued in the large eggs up to Gosner stage 28. Developmental time from hatching to metamorphosis was less than two weeks. We regard this developmental mode as an adaptation to the surprisingly high desiccation risks of the forest ponds in Tai National Park.

}, author = {R{\"o}del, Mark-Oliver and Kraetz, Daniel and Ernst, Raffael} } @article {340, title = {A review of West African spotted Kassina, including a description of Kassina schioetzi sp. nov. (Amphibia: Anura: Hyperoliidae)}, journal = {Copeia}, volume = {2002}, number = {3}, year = {2002}, month = {August 15, 2002}, pages = {800-814}, abstract = {

Based on museum specimens, field records, and morphological, acoustical, and geographical analyses, we resurrect the species status of Kassina arboricola Perret, 1985 and redefine Kassina cochranae (Loveridge, 1941). Additionally, we describe Kassina schioetzi sp. nov., a hitherto overlooked species. This species differs from K. cochranae and K. arboricola in several morphological features, especially the shape of the male gular flap, and its very short, tonal advertisement call. All three species are associated with forest habitats. Kassina schioetzi lives in wooded parts of the Guinea savanna of Ivory Coast and a single mountainous locality in eastern Guinea. Kassina cochranae occurs from western Ivory Coast to eastern Sierra Leone; K. arboricola occurs from Ghana to western Ivory Coast. At two localities, K. schioetzi occurs in syntopy with K. arboricola, and at another locality with K. cochranae. A key to all West African Kassina species is provided.

}, url = {://PREV200200524909}, author = {R{\"o}del, Mark-Oliver and Grafe, T. Ulmar and Rudolf, Volker H. W. and Ernst, Raffael} } @article {167, title = {Community assembly and structure of tropical leaf-litter anurans}, journal = {Ecotropica (Bonn)}, volume = {12}, number = {2}, year = {2006}, month = {2006}, pages = {113-129}, abstract = {We tested two traditional views of community organization relating to the individualistic continuum versus the interactive concept using anuran leaf-litter assemblages in primary and secondary forest habitats in Tai National Park (TNP), Ivory Coast as a model system. Based on biotic data and species occurrence patterns, the relative importance of each of these concepts was assessed. Null model tests of niche and size overlap revealed that the observed multivariate structure was only weakly influenced by biotic interactions, and therefore is most likely not the sole result of present species interactions. Non-metric multidimensional scaling and quadratic regression analyses showed that particular species responded to certain habitat characteristics, in particular the presence or absence of specific breeding sites and tree size classes, the latter being an index of forest degradation in this case. This corresponded to a discrimination of four major functional response groups within the leaf-litter community. However, the strength of these species-specific responses, and therefore the allocation to one or other of these response groups, varied throughout the year. Thus our results indicate that differing individual life histories, rather chair interspecific interactions, were likely explanations of the observed pattern. The leaf-litter anuran assemblages of TNP can be best described as a collection of loosely interacting individuals responding to particular sets of physiological constraints imposed by a particular location, rather than as a tightly integrated and highly interacting set of species.}, url = {://PREV200700085653}, author = {Ernst, Raffael and R{\"o}del, Mark-Oliver} } @article {166, title = {Anthropogenically induced changes of predictability in tropical anuran assemblages}, journal = {Ecology (Washington D C)}, volume = {86}, number = {11}, year = {2005}, month = {Nov 2005}, pages = {3111-3118}, abstract = {Anthropogenic habitat alteration has long been neglected as a factor in the analysis of predictability patterns in biological communities. We tested this factor by investigating anuran leaf litter assemblages in primary and secondary forests of Tai National Park, Ivory Coast, during two years.We measured predictability of assemblage composition by analyzing correlations between the off-diagonal elements of distance matrices based on (1) species distribution, (2) environmental characteristics, and (3) geographic distance. Pairwise correlations between matrices were significant in all cases when considering data pooled across time and habitats. A different pattern emerged when data were split according to season and disturbance level (i.e., primary vs. secondary habitats). Assemblage composition in primary habitats was correlated with geographic proximity of sites exclusively, indicating otherwise stochastic recruitment from a regional species pool at the local community level. In contrast, assemblage composition in secondary habitats was predictable based on environmental parameters, not geographical proximity. This can be inferred to be the result of a strong local site filter effect (i.e., physiologically more-restrictive conditions within secondary forest habitats, especially due to an altered microclimate). Results were consistent throughout seasons. The observed transition in predictability patterns indicates that anthropogenic disturbance not only affects system descriptors, such as species richness, abundance, and diversity, but may also alter the system{\textquoteright}s dynamics.}, url = {://PREV200600094521}, author = {Ernst, Raffael and R{\"o}del, Mark-Oliver} } @inbook {165, title = {Amphibian communities in disturbed forests: lessons from the Neo- and Afrotropics}, booktitle = {Environmental Science and Engineering}, series = {Environmental Science and Engineering:Environmental Engineering}, year = {2007}, pages = {61-87}, abstract = {Timber harvesting is currently the most common commercial utilisation activity in tropical forests. Assessing the effects of logging on different aspects of biodiversity and general ecosystem properties is hence of prime importance if the few remaining areas of intact tropical forest are to be protected effectively and efficiently.As we will point out in this chapter, tropical amphibian communities are an appropriate model system for studies on the impacts of human-induced environmental changes on the dynamics of complex biological systems. Here, we elaborate on patterns of diversity changes in tropical forest amphibian communities facing habitat alterations associated with selective logging in two globally important eco-regions (Cote d{\textquoteright}Ivoire, Upper Guinea, West Africa and Guyana, the Guiana Shield, northern South America), and discuss findings from other previously conducted studies with similar focus.A key statement that we stress on in this chapter is the fact that common measures of diversity, such as species richness and a-diversity only inadequately reflect processes of diversity change following anthropogenic disturbance. They also fail to describe actual impacts on the dynamics of complex biological systems. We argue that commonly used measures produce an incoherent and insufficient picture of diversity patterns and the underlying processes that shape these patterns. Thus, an understanding of higher levels of diversity, such as beta-diversity and functional diversity (and hence compositional patterns) appears to be the key to effectively mitigating the impacts of human-induced disturbance on amphibian communities.We show that the predictability of amphibian community composition depends on the respective level of anthropogenic disturbance imposed on a particular habitat. Hence, human activities that lead to changes in the structure of a forest, such as logging, not only alter simple system descriptors, such as the number of species in a given community, but rather alter the dynamics of the entire system. In this context, functional diversity is shown to be an important aspect underlying the actual mechanism that leads to the observed change of predictability patterns. Functional differences between species, rather than number of species per se appear to be the decisive factor in sustaining desirable ecosystem states and thus in maintaining important ecosystem services.Because biological diversity appears to play a substantial role in ecosystem resilience required to safeguard essential ecosystem functions in the face of environmental change, we call for a critical revision of common diversity assessments approaches. We advocate the reconsideration of the uncritical use of widespread measures and descriptors of biodiversity on grounds of inconsistent patterns found throughout numerous studies, including those presented herein.The complex nature of natural communities and the multiple aspects of biodiversity at different levels, make it necessary to incorporate processes acting on different organizational and spatial scales. When investigating the impacts of human-induced environmental changes on diverse vertebrate communities in the tropics, we should hence address compositional changes, as well as beta-, and functional aspects of biodiversity. Special attention should also be drawn to the particular disturbance history of a given site and large scale cross-regional comparisons should be given priority. The consideration of these approaches in future studies would likely provide deeper insight in ecosystem processes at large scales and improve the effectiveness of current ecosystem management strategies.}, url = {://PREV200800031242}, author = {Ernst, Raffael and Linsenmair, K. Eduard and Thomas, Raquel and R{\"o}del, Mark-Oliver} } @article {164, title = {Diversity erosion beyond the species level: Dramatic loss of functional diversity after selective logging in two tropical amphibian communities}, journal = {Biological Conservation}, volume = {133}, number = {2}, year = {2006}, month = {Nov 2006}, pages = {143-155}, abstract = {Assessing the effects of logging on different aspects of biodiversity and general ecosystem properties is of prime importance if the few remaining areas of intact tropical forest are to be efficiently protected. Commonly used measures of biodiversity may only inadequately reflect actual disturbance after logging and studies restricted to only one specific eco-region do not allow for generalizations of results. We hence measured the impact of selective logging on different levels of diversity of two tropical anuran communities in two geographically distinct eco-regions. Species-diversity patterns were incoherent both, within and between studies. In West Africa, species richness did not differ between primary and exploited forest sites, whereas South American anuran communities exhibited higher species richness in primary sites. Yet, in both eco-regions, functional diversity (FD) was higher in primary forest communities. Absolute values of FD were higher in South American anuran communities, despite higher species richness in West African communities. FD was higher in older recovery, as compared to younger recovery states, even though species-diversity did not differ significantly. Three major conclusions can be drawn from our results. 1. Scale matters: it is important to monitor different levels of biodiversity in order to reveal its actual loss after anthropogenic disturbance. 2. Time matters: the disturbance history of a site is important in order to detect patterns that otherwise remain unnoticed. 3. Geographic history matters at the local scale: whereas general patterns at higher diversity levels were identical in both eco-regions, species richness, species diversity and turnover patterns differed. (c) 2006 Elsevier Ltd. All rights reserved.}, url = {://PREV200700067947}, author = {Ernst, Raffael and Linsenmair, K. Eduard and R{\"o}del, Mark-Oliver} }