@misc{DammhahnGoodman2014, author = {Dammhahn, Melanie and Goodman, Steven M.}, title = {Trophic niche differentiation and microhabitat utilization revealed by stable isotope analyses in a dry-forest bat assemblage at Ankarana, northern Madagascar}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, issn = {1866-8372}, doi = {10.25932/publishup-41515}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415157}, pages = {97 -- 109}, year = {2014}, abstract = {Bats are important components in tropical mammal assemblages. Unravelling the mechanisms allowing multiple syntopic bat species to coexist can provide insights into community ecology. However, dietary information on component species of these assemblages is often difficult to obtain. Here we measuredstable carbon and nitrogen isotopes in hair samples clipped from the backs of 94 specimens to indirectly examine whether trophic niche differentiation and microhabitat segregation explain the coexistence of 16 bat species at Ankarana, northern Madagascar. The assemblage ranged over 4.4\% in delta N-15 and was structured into two trophic levels with phytophagous Pteropodidae as primary consumers (c. 3\% enriched over plants) and different insectivorous bats as secondary consumers (c. 4\% enriched over primary consumers). Bat species utilizing different microhabitats formed distinct isotopic clusters (metric analyses of delta C-13-delta N-15 bi-plots), but taxa foraging in the same microhabitat did not show more pronounced trophic differentiation than those occupying different microhabitats. As revealed by multivariate analyses, no discernible feeding competition was found in the local assemblage amongst congeneric species as compared with non-congeners. In contrast to ecological niche theory, but in accordance with studies on New and Old World bat assemblages, competitive interactions appear to be relaxed at Ankarana and not a prevailing structuring force.}, language = {en} } @article{DammhahnRakotondramananaGoodman2015, author = {Dammhahn, Melanie and Rakotondramanana, Claude Fabienne and Goodman, Steven M.}, title = {Coexistence of morphologically similar bats (Vespertilionidae) on Madagascar: stable isotopes reveal fine-grained niche differentiation among cryptic species}, series = {Journal of tropical ecology}, volume = {31}, journal = {Journal of tropical ecology}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {0266-4674}, doi = {10.1017/S0266467414000741}, pages = {153 -- 164}, year = {2015}, abstract = {Based on niche theory, closely related and morphologically similar species are not predicted to coexist due to overlap in resource and habitat use. Local assemblages of bats often contain cryptic taxa, which co-occur despite notable similarities in morphology and ecology. We measured in two different habitat types on Madagascar levels of stable carbon and nitrogen isotopes in hair (n = 103) and faeces (n = 57) of cryptic Vespertilionidae taxa to indirectly examine whether fine-grained trophic niche differentiation explains their coexistence. In the dry deciduous forest (Kirindy), six sympatric species ranged over 6.0\% in delta N-15, i.e. two trophic levels, and 4.2\% in delta C-13 with a community mean of 11.3\% in delta N-15 and - 21.0\% in delta C-13. In the mesic forest (Antsahabe), three sympatric species ranged over one trophic level (delta N-15: 2.4\%, delta C-13: 1.0\%) with a community mean of 8.0\% delta N-15 and - 21.7\% in delta C-13. Multivariate analyses and residual permutation of Euclidian distances in delta C-13- delta N-15 bi-plots revealed in both communities distinct stable isotope signatures and species separation for the hair samples among coexisting Vespertilionidae. Intraspecific variation in faecal and hair stable isotopes did not indicate that seasonal migration might relax competition and thereby facilitate the local co-occurrence of sympatric taxa.}, language = {en} } @misc{DammhahnRakotondramananaGoodman2015, author = {Dammhahn, Melanie and Rakotondramanana, Claude Fabienne and Goodman, Steven M.}, title = {Coexistence of morphologically similar bats (Vespertilionidae) on Madagascar}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {590}, issn = {1866-8372}, doi = {10.25932/publishup-41472}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414729}, pages = {12}, year = {2015}, abstract = {Based on niche theory, closely related and morphologically similar species are not predicted to coexist due to overlap in resource and habitat use. Local assemblages of bats often contain cryptic taxa, which co-occur despite notable similarities in morphology and ecology. We measured in two different habitat types on Madagascar levels of stable carbon and nitrogen isotopes in hair (n = 103) and faeces (n = 57) of cryptic Vespertilionidae taxa to indirectly examine whether fine-grained trophic niche differentiation explains their coexistence. In the dry deciduous forest (Kirindy), six sympatric species ranged over 6.0\% in delta N-15, i.e. two trophic levels, and 4.2\% in delta C-13 with a community mean of 11.3\% in delta N-15 and - 21.0\% in delta C-13. In the mesic forest (Antsahabe), three sympatric species ranged over one trophic level (delta N-15: 2.4\%, delta C-13: 1.0\%) with a community mean of 8.0\% delta N-15 and - 21.7\% in delta C-13. Multivariate analyses and residual permutation of Euclidian distances in delta C-13- delta N-15 bi-plots revealed in both communities distinct stable isotope signatures and species separation for the hair samples among coexisting Vespertilionidae. Intraspecific variation in faecal and hair stable isotopes did not indicate that seasonal migration might relax competition and thereby facilitate the local co-occurrence of sympatric taxa.}, language = {en} }