Biology Reference
In-Depth Information
Chapter 1
Background to Invasive Reptiles
and Amphibians
Concern about invasive alien species is a relatively new phenomenon that can be
dated to the work of Charles Elton, the ecologist who provided the first thorough
scrutiny of the topic. Elton (1958) demonstrated the severe ecological and human-
health impacts that invasive alien species can cause. Since then, the number of
introduced species has skyrocketed, and examples are now available to illustrate a
much larger array of resulting damages. The spatial scale of ecological harm result-
ing from alien invasions also continues to grow because virtually all environments
heavily impacted by humans are now dominated by alien species. Many “natural”
areas are also increasingly subject to alien invasion.
Scientific interest began to gather momentum in the 1980s, spurred by the publica-
tion of several edited topics on this topic (Groves and Burdon, 1986; Mooney and
Drake, 1986; Drake et al., 1989). Many scientific (e.g., M. Williamson, 1996; Mooney
and Hobbs, 2000; Perrings et al., 2000; McNeely, 2001; Mooney et al., 2005; Nentwig,
2007) and popular (e.g., Bright, 1998; Devine, 1998; G.W. Cox, 1999; Low, 1999; Van
Driesche and Van Driesche, 2000; Baskin, 2002) topics on the issue have appeared as
concern with the impacts of alien species became more widespread. A journal specifi-
cally devoted to the topic of biological invasions was founded in 1999, and the field is
increasingly replete with scientific studies addressing the dynamics and ecological
processes of invasion. There is also a recent spate of topics treating either specific
aspects of the invasive-species problem or summarizing the status of the topic in
particular geographic regions. In short, the topic is now well established in the scien-
tific mainstream, is attracting concerned attention among a wider public, and is increas-
ingly recognized as one of the premier environmental challenges of the new century.
In order to provide context and background information for considering the
phenomenon of invasiveness in reptiles and amphibians, this chapter presents a
brief introduction to invasive-species biology.
What Is an Invasive Species?
Terminology regarding invasive species has proliferated and changed through the
years, and a potentially confusing array of descriptors is available (Davis and
Thompson, 2000; Richardson et al., 2000a; Daehler, 2001). I use the term “alien
