Clarifying debates in invasion biology: A survey of invasion biologists

Invasion biology is a relatively new field, so there are ongoing debates about foundational issues regarding terminology and assessment of the causes and consequences of invasive species. These debates largely reflect differing views about the extent to which invasion biologists should advocate on behalf of native species. We surveyed reviewers of the journal Biological Invasions to obtain a better sense of how invasion biologists evaluate several foundational issues. We received 422 replies, which represented a very good response rate for an online survey of 42.5% of those contacted. Responses to several debates in the field were distributed bimodally, but respondents consistently indicated that contemporary biological invasions are unprecedented. Even still, this was not seen as justification for exaggerated language (hyperbole). In contrast to prevalent claims in the literature, only 27.3% of respondents ranked invasive species as the first or second greatest threat to biodiversity. The responses also highlighted the interaction of invasive species with other threats and the role of human activity in their spread. Finally, the respondents agreed that they need to be both more objective and better at communicating their results so that those results can be effectively integrated into management.

► We surveyed invasion biologists to assess how they respond to various debates in their field.
► Respondents mostly agreed that contemporary biological invasions are unprecedented.
► Only 27.3% of respondents ranked invasive species as the 1st or 2nd greatest threat to biodiversity.
► Results emphasize the synergistic effects of multiple anthropogenic stressors on these species.
► Respondents were mixed about the appropriate level of advocacy in their field.