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Abstract AimTropical regions harbour over half of the world's mammals and birds, but how their communities have assembled over evolutionary timescales remains unclear. To compare eco‐evolutionary assembly processes between tropical mammals and birds, we tested how hypotheses concerning niche conservatism, environmental stability, environmental heterogeneity and time‐for‐speciation relate to tropical vertebrate community phylogenetic and functional structure. LocationTropical rainforests worldwide. Time periodPresent. Major taxa studiedGround‐dwelling and ground‐visiting mammals and birds. MethodsWe used in situ observations of species identified from systematic camera trap sampling as realized communities from 15 protected tropical rainforests in four tropical regions worldwide. We quantified standardized phylogenetic and functional structure for each community and estimated the multi‐trait phylogenetic signal (PS) in ecological strategies for the four regional species pools of mammals and birds. Using linear regression models, we test three non‐mutually exclusive hypotheses by comparing the relative importance of colonization time, palaeo‐environmental changes in temperature and land cover since 3.3 Mya, contemporary seasonality in temperature and productivity and environmental heterogeneity for predicting community phylogenetic and functional structure. ResultsPhylogenetic and functional structure showed non‐significant yet varying tendencies towards clustering or dispersion in all communities. Mammals had stronger multi‐trait PS in ecological strategies than birds (mean PS: mammal = 0.62, bird = 0.43). Distinct dominant processes were identified for mammal and bird communities. For mammals, colonization time and elevation range significantly predicted phylogenetic clustering and functional dispersion tendencies respectively. For birds, elevation range and contemporary temperature seasonality significantly predicted phylogenetic and functional clustering tendencies, respectively, while habitat diversity significantly predicted functional dispersion tendencies. Main conclusionsOur results reveal different eco‐evolutionary assembly processes structuring contemporary tropical mammal and bird communities over evolutionary timescales that have shaped tropical diversity. Our study identified marked differences among taxonomic groups in the relative importance of historical colonization and sensitivity to environmental change.
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West Indian Mammals The Old, the New, and the Recently Extinct
The West Indian mammal fauna has played a key role in the development of biogeographic ideas for over a century, but a synthesis explaining regional patterns of mammal diversity and distribution in a historical framework has not emerged. We review recent phylogenetic, population genetic, and radiocarbon dating studies of West Indian mammals and explore the biological and historical drivers of colonization, speciation, and extinction in this region of endemism. We also present the first complete list of all its extant and extinct mammals. The mammalian biota is older than was earlier presumed, with many ancient endemic lineages, even among highly vagile organisms such as bats. Land bridges, Cenozoic eustatic sea-level changes, and Pleistocene glacial cycles have been proposed to explain the colonization of the islands, but phylogenetic divergence analyses often conlict with the timing of these events and favor alternative biogeographic histories. The loss of West Indian biodiversity is incompletely understood, but new radiometric chronologies indicate that anthropogenic impacts rather than glacial-interglacial environmental changes are responsible for most Quaternary extinction and extirpation events involving land mammals. However, many outstanding questions of historical biogeography remain unresolved, including appropriate methods for interpreting phylogenies and divergence estimates in a biogeographic context, and whether to use vicariance or dispersal as the null hypothesis when investigating regional patterns of colonization, speciation, and extinction in comparative analyses. We propose synthetic approaches drawing from phylogenetics, population genetics, paleogeography, paleontology, and even archaeology to resolve persisting questions in Caribbean biogeography.
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- Award ID(s):
- 0949759
- PAR ID:
- 10017046
- Date Published:
- Journal Name:
- Bones, Clones, and Biomes: An Extended History of Recent Neotropical Mammals
- Page Range / eLocation ID:
- 157-202
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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