TY  - GEN
A1  - Dammhahn, Melanie
A1  - Goodman, Steven M.
T1  - Trophic niche differentiation and microhabitat utilization revealed by stable isotope analyses in a dry-forest bat assemblage at Ankarana, northern Madagascar
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - 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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 595 
KW  - Ankarana
KW  - canopy effect
KW  - Chiroptera
KW  - coexistence
KW  - community structure
KW  - congeneric species
KW  - dry deciduous forest
KW  - Madagascar
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-415157
SN  - 1866-8372
SP  - 97
EP  - 109
ER  - 
TY  - GEN
A1  - Dammhahn, Melanie
A1  - Rakotondramanana, Claude Fabienne
A1  - Goodman, Steven M.
T1  - Coexistence of morphologically similar bats (Vespertilionidae) on Madagascar
BT  - stable isotopes reveal fine-grained niche differentiation among cryptic species
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - 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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 590 
KW  - Chiroptera
KW  - community structure
KW  - congeneric species
KW  - ecological niches
KW  - migration
KW  - Neoromicia
KW  - Pipistrellus
KW  - Scotophilus
KW  - stable carbon
KW  - stable nitrogen
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-414729
SN  - 1866-8372
IS  - 590
ER  -