Species traits and island biogeography: wing metrics linked to avian dispersal ability predict species occurrence on remote islands worldwide
Author(s)
Bastidas-Urrutia, Ana Maria
Biber, Matthias F
Boehning-Gaese, Katrin
Fritz, Susanne A
Kreft, Holger
Type
Journal Article
Abstract
Aim
We assessed the influence of island isolation on the composition of insular bird assemblages with a particular focus on species traits associated with dispersal. To do so, we tested whether ecomorphological metrics of dispersal ability, namely hand-wing index and Kipp's distance, increase with increasing island isolation.
Location
Global.
Taxon
Birds.
Methods
We integrated global datasets of island characteristics with distribution and ecomorphological trait information of birds; our final dataset comprised information for 2034 native, resident and terrestrial species inhabiting 2399 islands. Species restricted to islands were removed to avoid potentially confounding effects of speciation, such as the evolution of flightlessness or poor flight on islands. Using the generalised additive models, we tested for the relationship between hand-wing index or Kipp's distance and island isolation, accounting for the effects of island area and spatial autocorrelation. We performed the analyses separately for (i) continental and oceanic islands and (ii) for all terrestrial birds and for passerine birds only.
Results
Hand-wing index and Kipp's distance were positively related to island isolation on oceanic islands, that is bird communities on more isolated oceanic islands were composed of species with wings that had a higher aspect ratio and were more elongated. However, this relationship did not hold for continental islands. We found these patterns to be consistent for all terrestrial birds as well as for passerine birds only.
Main Conclusion
Our study provides strong evidence that island isolation influences the trait composition of island bird assemblages at a global scale. Our results highlight the variation of dispersal-related ecomorphological traits among bird assemblages on islands, suggesting that these traits play an important role in mediating the influence of island isolation on community assembly processes on islands.
We assessed the influence of island isolation on the composition of insular bird assemblages with a particular focus on species traits associated with dispersal. To do so, we tested whether ecomorphological metrics of dispersal ability, namely hand-wing index and Kipp's distance, increase with increasing island isolation.
Location
Global.
Taxon
Birds.
Methods
We integrated global datasets of island characteristics with distribution and ecomorphological trait information of birds; our final dataset comprised information for 2034 native, resident and terrestrial species inhabiting 2399 islands. Species restricted to islands were removed to avoid potentially confounding effects of speciation, such as the evolution of flightlessness or poor flight on islands. Using the generalised additive models, we tested for the relationship between hand-wing index or Kipp's distance and island isolation, accounting for the effects of island area and spatial autocorrelation. We performed the analyses separately for (i) continental and oceanic islands and (ii) for all terrestrial birds and for passerine birds only.
Results
Hand-wing index and Kipp's distance were positively related to island isolation on oceanic islands, that is bird communities on more isolated oceanic islands were composed of species with wings that had a higher aspect ratio and were more elongated. However, this relationship did not hold for continental islands. We found these patterns to be consistent for all terrestrial birds as well as for passerine birds only.
Main Conclusion
Our study provides strong evidence that island isolation influences the trait composition of island bird assemblages at a global scale. Our results highlight the variation of dispersal-related ecomorphological traits among bird assemblages on islands, suggesting that these traits play an important role in mediating the influence of island isolation on community assembly processes on islands.
Date Issued
2025-02-01
Date Acceptance
2024-10-13
Citation
Journal of Biogeography, 2025, 52 (2), pp.350-361
ISSN
0305-0270
Publisher
Wiley
Start Page
350
End Page
361
Journal / Book Title
Journal of Biogeography
Volume
52
Issue
2
Copyright Statement
© 2024 The Author(s). Journal of Biogeography published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
License URL
Identifier
10.1111/jbi.15038
Subjects
AREA
birds
BIRDS
colonisation
COLONIZATION
community assembly
dispersal
DISTANCE
DIVERSITY
Ecology
ecomorphology
Environmental Sciences & Ecology
EVOLUTION
EXTINCTIONS
functional traits
Geography, Physical
hand-wing index
island biogeography
isolation
Kipp's distance
Life Sciences & Biomedicine
MODEL
PATTERNS
Physical Geography
Physical Sciences
RICHNESS
Science & Technology
Publication Status
Published
Date Publish Online
2024-11-13