Ecological biogeography of Malagasy non‐volant mammals: community structure is correlated with habitat

Abstract

Aim To examine the relationship between ecoregions, as a proxy for regional climate and habitat type, and mammalian community structure, defined by species composition and richness (e.g. taxonomic structure) and ecological diversity (e.g. ecological structure) of non-volant species.Location Madagascar.Methods Faunal lists of non-volant mammal species occurring in 35 communities from five World Wildlife Fund ecoregions were collected from published and unpublished sources. Species were assigned to ecological groups defined by trophic status, locomotor habits, activity cycle and body mass. We used Mantel tests, cluster analysis and principal coordinates analysis to evaluate geographic patterning in taxonomic composition and species richness. We used stepwise multiple discriminant analysis to characterize patterns in the ecological diversity of the mammalian communities from each ecoregion. Communities from transitional habitats (e.g. representing more than one ecoregion) were used to test the predictive power of the analyses.Results Non-volant mammal communities divided into clusters that correspond to ecoregions. There was a strong distance effect in the taxonomic structure of communities across the island and within both humid and dry forest communities, but this effect was weak within humid forest communities. Mammalian species richness was significantly lower in dry forest than in humid forest communities. The ecological structure of communities was also correlated with ecoregions. Changes in the relative percentages of omnivory, arboreal quadrupedalism, terrestrial/arboreal quadrupedalism and two body mass classes accounted for 98.1% of the variation in ecological structure. Transitional communities were projected in intermediate positions by the discriminant model.Main conclusions Our analysis demonstrates that the broad-scale habitat and climate variables captured by the ecoregion model have shaped the assembly of non-volant mammal communities in Madagascar over evolutionary time. The spatial pattern is consistent with ecological sorting of species ranges along environmental gradients. Historical processes, such as recent extinction and migration, may have also affected the structure of mammal communities, although these factors have played a secondary role.

Interactions between plants and primates shape community diversity in a rainforest in Madagascar

“…Competitive exclusion may prevent coexistence of close relatives in the same dietary guilds (Kamilar & Ledogar ), and co‐occurring species show divergence in traits such as activity pattern and social structure (Fleagle & Reed ; Ossi & Kamilar ). There is also evidence for environmental filtering: similar environments have similar taxonomic compositions and niche diversity (Reed & Fleagle ; Kamilar ; Muldoon & Goodman ). Resource availability may be the most important factor limiting the diversity and abundance of primates in communities, filtering species and dietary guild composition (Janson & Chapman ).…”

Evidence for Dietary Niche Separation Based on Infraorbital Foramen Size Variation among Subfossil Lemurs

“…Next, to verify that relative IOF area reflects diet in extant lemurs, we tested the significance of differences among our 3 dietary groups, again with and without incorporating phylogenetic information. We then examined the relative IOF area scores for extinct lemurs, using their Mahalanobis distances from the 3 extant lemur dietary group centroids to classify [Wright and Martin, 1995;Lahann, 2007;Muldoon and Goodman, 2010] Cheirogaleus medius OM Fruit, nectar, flowers, animals Fietz and Ganzhorn, 1999;Lahann, 2007] …”

“…OM Fruit, arthropods, gums, insect secretions, small vertebrates [Radespiel et al, 2006;Lahann, 2007;Dammhahn and Kappeler, 2008] Mirza coquereli OM Fruit, flowers, gums, insect secretions, insects Muldoon and Goodman, 2010] Daubentoniidae Daubentonia madagascariensis OM Fruit, nut kernels, nectar, ants, beetle larvae, termites, earwigs [Sterling, 1994;Lhota et al, 2008] Indriidae…”

Early Holocene fauna from a new subfossil site: A first assessment from Christmas River, south central Madagascar

“…), about 83 km further west (Mahé andSourdat 1972, Jernvall et al 2003). Although these localities yield much more recent dates An east -west distance effect in extant mammal distribu--west distance effect in extant mammal distribu--west distance effect in extant mammal distribuwest distance effect in extant mammal distribuwest distance effect in extant mammal distributions has been interpreted as evidence that faunal exchange routes once crossed the southern portion of the central highlands (Godfrey et al 1999, Muldoon andGoodman 2010). It has been hypothesized that this corridor was fragmented by shifts in vegetation associated with climate change, but given that much of the natural habitat across this zone no longer exists, it is difficult to reconstruct its former extent and type.…”

“…Today, the central highlands are dominated by grasslands that act as a significant barrier to faunal exchange across the island (Muldoon and Goodman 2010). However, the subfossil record of southern Madagascar reveals that numerous extant species once occurred in regions where they do not live today (Goodman and Rakotondravony 1996, Goodman and Rakotozafy 1997, Godfrey et al 1999, 2007, Muldoon et al 2009).…”