Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Independent colonization of multiple urban centres by a formerly forest specialist bird species
AU - Evans, Karl L.
AU - Gaston, Kevin J.
AU - Frantz, Alain C.
AU - Simeoni, Michelle
AU - Sharp, Stuart P.
AU - McGowan, Andrew
AU - Dawson, Deborah A.
AU - Walasz, Kazimierz
AU - Partecke, Jesko
AU - Burke, Terry
AU - Hatchwell, Ben J.
PY - 2009/7/7
Y1 - 2009/7/7
N2 - Urban areas are expanding rapidly, but a few native species have successfully colonized them. The processes underlying such colonization events are poorly understood. Using the blackbird Turdus merula, a former forest specialist that is now one of the most common urban birds in its range, we provide the first assessment of two contrasting urban colonization models. First, that urbanization occurred independently. Second, that following initial urbanization, urban-adapted individuals colonized other urban areas in a leapfrog manner. Previous analyses of spatial patterns in the timing of blackbird urbanization, and experimental introductions of urban and rural blackbirds to uncolonized cities, suggest that the leapfrog model is likely to apply. We found that, across the western Palaearctic, urban blackbird populations contain less genetic diversity than rural ones, urban populations are more strongly differentiated from each other than from rural populations and assignment tests support a rural source population for most urban individuals. In combination, these results provide much stronger support for the independent urbanization model than the leapfrog one. If the former model predominates, colonization of multiple urban centres will be particularly difficult when urbanization requires genetic adaptations, having implications for urban species diversity.
AB - Urban areas are expanding rapidly, but a few native species have successfully colonized them. The processes underlying such colonization events are poorly understood. Using the blackbird Turdus merula, a former forest specialist that is now one of the most common urban birds in its range, we provide the first assessment of two contrasting urban colonization models. First, that urbanization occurred independently. Second, that following initial urbanization, urban-adapted individuals colonized other urban areas in a leapfrog manner. Previous analyses of spatial patterns in the timing of blackbird urbanization, and experimental introductions of urban and rural blackbirds to uncolonized cities, suggest that the leapfrog model is likely to apply. We found that, across the western Palaearctic, urban blackbird populations contain less genetic diversity than rural ones, urban populations are more strongly differentiated from each other than from rural populations and assignment tests support a rural source population for most urban individuals. In combination, these results provide much stronger support for the independent urbanization model than the leapfrog one. If the former model predominates, colonization of multiple urban centres will be particularly difficult when urbanization requires genetic adaptations, having implications for urban species diversity.
KW - HABITAT
KW - genetic divergence
KW - URBANIZATION
KW - POLYMORPHISM
KW - INDIVIDUALS
KW - genetic diversity
KW - ASSIGNMENT METHODS
KW - range expansion
KW - SIMULATION
KW - colonization
KW - dispersal
KW - NUMBER
KW - urban
KW - EUROPEAN BLACKBIRDS
KW - POPULATION-STRUCTURE
KW - EVOLUTION
U2 - 10.1098/rspb.2008.1712
DO - 10.1098/rspb.2008.1712
M3 - Journal article
VL - 276
SP - 2403
EP - 2410
JO - Proceedings of the Royal Society B: Biological Sciences
JF - Proceedings of the Royal Society B: Biological Sciences
SN - 0962-8452
IS - 1666
ER -