The role played by invasive species in interactions with endangered and threatened species in the United States: a systematic review

Manuel-Angel Dueñas,Nicola H Wakefield,Philip D Roberts,Holly J Ruffhead,Hilda Diaz-Soltero,David J Hemming

doi:10.1007/s10531-018-1595-x

Manuel-Angel Dueñas, Nicola H Wakefield + Show 4 more

Open Access

https://doi.org/10.1007/s10531-018-1595-x

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Abstract

Invasive species are considered to be a leading cause of the decline of threatened species. However, this view has been disputed because much of the evidence base is anecdotal. This systematic review, through an extensive, repeatable search using agreed selection criteria, examined the available scientific evidence on invasive species’ interactions with the 1363 endangered and threatened species protected under the United States Endangered Species Act (ESA). The review found scientific evidence available for 116 endangered or threatened species (8.5% of the ESA list). Of these, 85 species (6.2%) were reported as being negatively impacted by invasive species: 39 located on the continental US and 39 on islands, with seven marine species. The relative percentages of species impacted differed according to location: 4.3% (n = 906) on the continental US, 9.3% (n = 420) on islands. It was found that predation by invasive vertebrates on birds on islands and competition between invasive plants and endangered or threatened plants on the mainland were the main mechanisms of impact. The results of this study contrast markedly with a previous study which found that 49% of imperilled species in the United States were threatened by invasive species. Further research is essential in order to evaluate the impact of invasive species on imperilled species on the ESA list; this would help to reduce the high degree of uncertainty regarding the threat of invasive species due to the lack of empirical information.

Highlights

Biological invasions are considered a major part of global change (e.g. Vitousek et al 1997; NRC 2000; Sala et al 2000; MEA 2005; Mooney et al 2005; Richardson and Pyšek 2008; Davis 2009)
This systematic review was carried out following the guidelines specific to conservation interventions developed for the Collaboration for Environmental Evidence (CEE) (Pullin and Stewart 2006; CEE 2013)
Many of the references selected in the review were based on observational studies, which were frequently descriptive field studies and sometimes circumstantial correlation or speculation based on limited observation, and quite often based on assumptions, correlations or merely on the presence of invasive species, rather than on experimental and/or detailed field observations to determine their impacts

Summary

Introduction

Biological invasions are considered a major part of global change (e.g. Vitousek et al 1997; NRC 2000; Sala et al 2000; MEA 2005; Mooney et al 2005; Richardson and Pyšek 2008; Davis 2009). Invasive species can significantly alter ecosystem processes and functions (Vitousek 1990; Mack et al 2000; Pyšek and Richardson 2010; Vilà et al 2011). This can result in major environmental damage and economic losses, amounting to $120 billion annually in the United States alone (Pimentel et al 2005). They cause declines in biodiversity (Powell et al 2011) and affect disturbance regimes (Mack and D’Antonio 1998). Identical rankings have been identified for the United States despite the different taxa and data sources used (Flather et al 1994; Schemske et al 1994; Czech and Krausman 1997; Richter et al 1997; Foin et al 1998; Wilcove et al 1998; Lawler et al 2002; Wagner and Van Driesche 2010)

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