My research primarily addresses questions relating to human-mediated biological invasions, on which I am an internationally recognised expert. Invasions are now so pervasive that alien species are a central element of current global environmental change, and a major drain on economic resources, giving a strong incentive to understand the process that leads to a species becoming invasive.

Progress in uncovering the rules governing the invasion process has come from studies that explicitly analyse the passage of taxa through the sequential stages in the invasion pathway (transport; introduction; establishment; spread). My initial work identified how biases in the early part of the process can affect interpretation of success (Blackburn & Duncan 2001, J. Biogeogr.), and how modeling these biases can identify characteristics that influence establishment success (Blackburn & Duncan 2001, Nature). Subsequent work showed the importance of propagule pressure (Lockwood et al. 2005, Trends Ecol. Evol.) and cognition (Sol et al. 2005, Proc. Natl Acad. Sci. USA) in establishment, and defined frameworks for studying the invasion process (Duncan et al. 2003, Annu. Rev. Ecol. Syst.; Blackburn et al. 2011, Trends Ecol. Evol.). A related interest has been extinction risk in island birds (Blackburn et al. 2004, Ecography, Duncan et al. 2013, Proc. Natl Acad. Sci. USA), where my work includes studies on how invasive species impact on native bird extinctions on islands worldwide (Blackburn et al. 2004, Science), evidence for prehistoric hunting as a driver of extinction risk (Duncan et al. 2002, Proc. R. Soc. Lond. B.), and the impact of invasions on biotic homogenization (Cassey et al. 2007, J. Biogeogr.). Much of this work is reviewed and placed in its wider context in my monograph on bird invasions (Blackburn et al. 2009, Avian Invasions. The ecology and evolution of exotic birds).

My current work aims to continue to develop understanding of invasions, using birds as a model taxon, and particularly focusing on later stages of the pathway.  I have overseen development of a novel, spatially and temporally referenced, global data set on the distribution of all exotic bird populations worldwide. The Global Avian Invasions Atlas (or GAVIA) project comprises >25,000 distribution records for >900 alien bird species, which will allow the spatial and temporal dynamics of alien bird population spread to be explored. I have also recently developed a method to evaluate, compare and predict the impacts of different alien species, that can be applied to impacts that occur at different levels of ecological complexity, at different spatial and temporal scales, and assessed using a range of metrics and techniques (Blackburn et al. 2014, PLoS Biol.).  I plan to use this method to understand variation in the impacts of different alien species and higher taxa, and to develop blacklists of alien species for use in conservation policy and practice.