Strangers in a Strange Land: The Problem of Exotic Species

Abstract

Environmentalists consider invasions by exotic species of plants and animals to be one of the most serious environmental problems we face today, as well as one of the leading causes of biodiversity loss. We argue that in order to develop and enact sensible policies, it is crucial to consider two philosophical questions: (1) What exactly makes a species native or exotic, and (2) What values are at stake? We focus on the first of these two questions, and offer some preliminary suggestions with regard to the second. Through a series of case studies, we show that it is not always clear whether a species is native or exotic. We identify five possible criteria that could be used for distinguishing natives from exotics. Rather than identifying one of these criteria as the 'correct' one, we suggest that the concepts of 'native' and 'exotic' function more like what some philosophers have called cluster concepts. That is, there are several characteristics that are typical of native species, and a corresponding set of characteristics that are typical of exotic species. None of these characteristics is either necessary or sufficient for identifying a species as either native or exotic. We then identify several of the values that are at stake in dealing with exotic species, and we suggest that policies need to avoid being overly simplistic.

Biological invasions and biocultural diversity: linking ecological and cultural systems

“…A few philosophers, historians and social scientists have addressed the sociocultural dimensions of invasive species, often with contentious results (Woods & Moriarity 2001;Clayton 2003;Beinart & Middleton 2004;Robbins 2004;Helmreich 2005;Larson 2005), as the destructive ecological impact of bioinvasions makes it difficult for many scientists to remain objective. Yet ignorance of the multifaceted cultural aspects of biological invasions is counterproductive.…”

Metaphors in Invasion Biology: Implications for Risk Assessment and Management of Non-Native Species

“…It has been argued that the use of such terms reinforces militaristic thought patterns with regard to invasive species management, while the parallels in wording with immigration policy have led to accusations of xenophobia (Larson, 2005;O'Brien, 2006). Furthermore, the distinction between native and non-native species has received criticism from various academic disciplines, such as geography, biology, and philosophy, notably because of the lack of objective criteria and spatiotemporal references for defining what is 'native' and 'non-native' (Warren, 2007;Webber & Scott, 2012;Woods & Moriarty, 2001). It has come to a point where critics are advocating for the 'end of invasion biology' based on its perceived xenophobic stance, the ambiguity of definitions, and lack of foundation as such (Valéry, Fritz, & Lefeuvre, 2013).…”

The role of ethics in the management of New Zealand's wild mammals

“…Resident introduced species, though immediately lacking historical associations in their new lands, just like any naturally invading species, may come to be regarded as naturalised once sufficiently co-adapted to their new environment (Woods & Moriarty 2001).…”

“…As Woods & Moriarty (2001) note, decisions on the management of introduced pest species are influenced by a range of values, including not only ecosystem health and biodiversity protection, but wilderness protection, animal welfare and various anthropocentric (human-centred) economic, cultural, and recreational values. Selection of ecological management objectives is a value-laden process requiring human choices in circumstances of considerable uncertainty of outcome (SchraderFrechette 1995).…”