Establishment Success across Convergent Mediterranean Ecosystems: an Analysis of Bird Introductions SALIT KARK ∗ AND DANIEL SOL† ∗ The Biodiversity Research Group, Department of Evolution, Systematics and Ecology, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, email salit@cc.huji.ac.il †Centre de Recerca Ecol` ogica i Aplicacions Forestals (CREAF), Universitat Aut` onoma de Barcelona, E-08193 Bellaterra, Catalonia, Spain Abstract: Concern over the impact of invaders on biodiversity and on the functioning of ecosystems has gen- erated a rising tide of comparative analyses aiming to unveil the factors that shape the success of introduced species across different regions. One limitation of these studies is that they often compare geographically rather than ecologically defined regions. We propose an approach that can help address this limitation: comparison of invasions across convergent ecosystems that share similar climates. We compared avian invasions in five convergent mediterranean climate systems around the globe. Based on a database of 180 introductions repre- senting 121 avian species, we found that the proportion of bird species successfully established was high in all mediterranean systems (more than 40% for all five regions). Species differed in their likelihood to become estab- lished, although success was not higher for those originating from mediterranean systems than for those from nonmediterranean regions. Controlling for this taxonomic effect with generalized linear mixed models, species introduced into mediterranean islands did not show higher establishment success than those introduced to the mainland. Susceptibility to avian invaders, however, differed substantially among the different mediterranean regions. The probability that a species will become established was highest in the Mediterranean Basin and lowest in mediterranean Australia and the South African Cape. Our results suggest that many of the birds recently introduced into mediterranean systems, and especially into the Mediterranean Basin, have a high potential to establish self-sustaining populations. This finding has important implications for conservation in these biologically diverse hotspots. Key Words: biological invasions, birds, convergence, GLMM, introduced species, mediterranean-climate systems Exitoso de Establecimiento en Ecosistemas Mediterr´ aneos Convergentes: un An´ alisis de Introducciones de Aves Resumen: La preocupaci´ on por el impacto de las especies invasores sobre la biodiversidad y el funcionami- ento de los ecosistemas ha generado una creciente ola de an´ alisis comparativos que tratan de revelar los factores que moldean el ´ exito de las especies introducidas en diferentes regiones. Una limitaci´ on de esos es- tudios es que a menudo comparan regiones definidas geogr´ aficamente y no ecol´ ogicamente. Proponemos un m´ etodo que puede ayudar a superar esa limitaci´ on: la comparaci´ on de invasiones en ecosistemas con- vergentes que comparten climas similares. Comparamos las invasiones de aves en cinco sistemas clim´ aticos mediterr´ aneos alrededor del mundo. A partir de una base de datos de 180 introducciones representando a 121 especies de aves, encontramos que la proporci´ on de especies de aves que se establecieron exitosamente fue alta en todos los sistemas mediterr´ aneos (m´ as de 40% en las cinco regiones). Las especies difirieron en la probabilidad de establecimiento, aunque el ´ exito no fue mayor para aquellas que se originaron en sistemas mediterr´ aneos en comparaci´ on con las provenientes de regiones no mediterr´ aneas. Controlando este efecto Paper received July 13, 2004; revised manuscript accepted November 18, 2004. 1519 Conservation Biology 1519–1527 C 2005 Society for Conservation Biology DOI: 10.1111/j.1523-1739.2005.00208.x