Recent Dispersal Events among Solomon Islands Bird Species Reveal Differing Potential Routes of Island Colonization1

• Published in: Pacific science Vol. 70; no. 2; pp. 201 - 208
• Main Author: Sardell, Jason M.
• Format: Journal Article
• Language: English
• Published: University of Hawai'i Press 01.04.2016
• Subjects: biodiversity; birds; colonizing ability; extinction; habitat destruction; islands; phylogeny; satellites; Solomon Islands; species dispersal; Solomon Islands
• ISSN: 0030-8870; 1534-6188; 1534-6188
• DOI: 10.2984/70.2.6

Species assemblages on islands are products of colonization and extinction events, with traditional models of island biogeography emphasizing build-up of biodiversity on small islands via colonizations from continents or other large landmasses. However, recent phylogenetic studies suggest that islands can also act as sources of biodiversity, but few such “upstream” colonizations have been directly observed. I report four putative examples of recent range expansions among the avifauna of Makira and its satellite islands in the Solomon Islands, a region that has recently been subject to extensive anthropogenic habitat disturbance. They include three separate examples of inter island dispersal, involving Geoffroyus heteroclitus, Cinnyris jugularis, and Rhipidura rufifrons, which together represent three distinct possible patterns of colonization, and one example of probable downslope altitudinal range expansion in Petroica multicolor. Because each of these species is easily detected when present, and because associated localities were visited by several previous expeditions, these records likely represent recent dispersal events rather than previously overlooked rare taxa. These observations demonstrate that both large landmasses and small islands can act as sources of island biodiversity, while providing insights into the potential for habitat alteration to facilitate colonizations and range expansions in island systems.