Current address: Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, D-60325 Frankfurt (Main), Germany
DIVERSIFICATION AND BIOGEOGRAPHIC PATTERNS IN FOUR ISLAND RADIATIONS OF PASSERINE BIRDS
Version of Record online: 1 SEP 2011
© 2011 The Author(s). Evolution © 2011 The Society for the Study of Evolution.
Volume 66, Issue 1, pages 179–190, January 2012
How to Cite
Fritz, S. A., Jønsson, K. A., Fjeldså, J. and Rahbek, C. (2012), DIVERSIFICATION AND BIOGEOGRAPHIC PATTERNS IN FOUR ISLAND RADIATIONS OF PASSERINE BIRDS. Evolution, 66: 179–190. doi: 10.1111/j.1558-5646.2011.01430.x
- Issue online: 3 JAN 2012
- Version of Record online: 1 SEP 2011
- Accepted manuscript online: 11 AUG 2011 07:43PM EST
- Received April 28, 2011, Accepted July 18, 2011
- diversity dependence;
- species richness
Declining diversification rates over time are a well-established evolutionary pattern, often interpreted as indicating initial rapid radiation with filling of ecological niche space. Here, we test the hypothesis that island radiations may show constant net diversification rates over time, due to continued expansion into new niche space in highly dispersive taxa. We investigate diversification patterns of four passerine bird families originating from the Indo-Pacific archipelagos, and link these to biogeographic patterns to provide independent indications of niche filling. We find a declining diversification rate for only one family, the Paradisaeidae (41 species). These are almost completely restricted to New Guinea, and have on average smaller species ranges and higher levels of species richness within grid cells than the other three families. In contrast, we cannot reject constant diversification rates for Campephagidae (93 species), Oriolidae (35 species), and Pachycephalidae (53 species), groups that have independently colonized neighboring archipelagos and continents. We propose that Paradisaeidae have reached the diversity limit imposed by their restricted distribution, whereas high dispersal and colonization success across the geologically dynamic Indo-Pacific archipelagos may have sustained high speciation rates for the other three families. Alternatively, increasing extinction rates may have obscured declining speciation rates in those three phylogenies.