Abstract
Aim: Whether entire communities of organisms converge towards predictable structural properties in similar environmental conditions remains controversial. We tested for community convergence in birds by comparing the structure of oceanic archipelago assemblages with their respective regional species pools.
Location: Eighteen major oceanic archipelagos of volcanic origin with global distribution.
Major taxa studied: Terrestrial birds.
Methods: We compiled a comprehensive database of morphological trait and phylogenetic data for 6,579 bird species, including species known to have become extinct owing to human activities. We quantified morphological and phylogenetic dissimilarity among species between pairs of archipelagos, using a modified version of the mean nearest taxon distance. We tested for convergence by estimating whether overall mean turnover among archipelagos and pairwise turnover between archipelagos were lower than expected by chance.
Results: For all land birds, we found that turnover in body plan, body mass and phylogeny among archipelagos was significantly lower than expected. Seventeen (of 18) archipelagos showed significant body plan and phylogenetic similarity with at least one other archipelago. Similar convergent patterns of community assembly were detected in different subsamples of the data (extant species, endemics, native non-endemics, and Passeriformes only). Convergence was more pronounced for extant species than for extant and extinct species combined.
Main conclusions: Consistent convergence in phylogenetic and morphological structure among archipelagic communities arises through a combination of non-random colonization and in situ adaptation. In addition, by including data from extinct taxa, we show that community convergence both precedes and is accentuated by the anthropogenic extinction of endemic lineages. Our results highlight the potential role of non-random extinction in generating patterns of community convergence and show that convergence existed even before anthropogenic extinctions, owing to deterministic community assembly in similar environmental settings at the global scale.
Location: Eighteen major oceanic archipelagos of volcanic origin with global distribution.
Major taxa studied: Terrestrial birds.
Methods: We compiled a comprehensive database of morphological trait and phylogenetic data for 6,579 bird species, including species known to have become extinct owing to human activities. We quantified morphological and phylogenetic dissimilarity among species between pairs of archipelagos, using a modified version of the mean nearest taxon distance. We tested for convergence by estimating whether overall mean turnover among archipelagos and pairwise turnover between archipelagos were lower than expected by chance.
Results: For all land birds, we found that turnover in body plan, body mass and phylogeny among archipelagos was significantly lower than expected. Seventeen (of 18) archipelagos showed significant body plan and phylogenetic similarity with at least one other archipelago. Similar convergent patterns of community assembly were detected in different subsamples of the data (extant species, endemics, native non-endemics, and Passeriformes only). Convergence was more pronounced for extant species than for extant and extinct species combined.
Main conclusions: Consistent convergence in phylogenetic and morphological structure among archipelagic communities arises through a combination of non-random colonization and in situ adaptation. In addition, by including data from extinct taxa, we show that community convergence both precedes and is accentuated by the anthropogenic extinction of endemic lineages. Our results highlight the potential role of non-random extinction in generating patterns of community convergence and show that convergence existed even before anthropogenic extinctions, owing to deterministic community assembly in similar environmental settings at the global scale.
| Original language | English |
|---|---|
| Pages (from-to) | 1741-1755 |
| Number of pages | 15 |
| Journal | Global Ecology and Biogeography |
| Volume | 31 |
| Issue number | 9 |
| Early online date | 10 Jun 2022 |
| DOIs | |
| Publication status | Published - Sept 2022 |
Bibliographical note
Funding Information:We thank the numerous field biologists who collected specimens used in this study; the Natural History Museum, the American Museum of Natural History and 63 other research collections for providing access to specimens; Juan Carlos Illera for providing a list of Macaronesian birds; and Kostas Sagonas for drawing Figure 1. We are also grateful to Robert Freckleton for statistical advice and to Bob Ricklefs, Rosemary Gillespie and Jon Chase for feedback on previous versions of the manuscript. Luis Valente and an anonymous reviewer provided insightful comments that helped us to improve the manuscript. The image of Hawaiian honeycreepers is courtesy of D. Pratt (North Carolina Museum of Natural Sciences, Raleigh). K.A.T was supported by a visiting scientist fellowship from Agence Nationale la Recherche TULIP LabEx program (no. ANR-10-LABX-41). J.A.T was supported by Natural Environment Research Council grants NE/I028068/1 and NE/P004512/1.
Funding Information:
This study was supported by the Colorado Clinical and Translational Sciences Institute (CCTSI). The CCTSI is supported in part by Colorado CTSA Grant UL1TR002535 from NCATS/NIH.
Publisher Copyright:
© 2022 John Wiley & Sons Ltd.
Keywords
- birds
- community assembly
- convergence
- determinism
- extinct species
- historical contingency
- island biogeography
- morphological traits
- oceanic archipelagos