Lack of Behavioral and Chemical Interference Competition for Refuges among Native Treefrogs and Invasive Cuban Treefrogs (Osteopilus septentrionalis)

Kristine Hoffmann,Steve Johnson,Monica Mcgarrity

doi:10.3390/d10030078

Kristine Hoffmann, Steve Johnson + Show 1 more

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https://doi.org/10.3390/d10030078

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Abstract

The introduction of a novel competitor can dramatically alter community dynamics, and competition-mediated impacts often result from biological invasions. Interference competition can be especially problematic as a source of methodological bias for studies seeking to evaluate population and community-level impacts of invasive species. We used polyvinyl chloride (PVC) refugia to conduct laboratory trials to determine whether behavioral or chemical cues of invasive Cuban treefrogs (Osteopilusseptentrionalis) interfere with artificial refuge use by conspecifics or treefrogs native to Florida (USA). We found no evidence of behavioral or chemical competition for refuges by Cuban treefrogs or native treefrogs. The inability of native treefrogs to avoid chemical cues from Cuban treefrogs, despite living sympatrically with the invasive treefrogs for 10–20 years, has important implications for predation risk.

Highlights

Competition within and among species can limit their distribution and abundance [1,2]
The presence of a Cuban treefrog did not influence the likelihood that a native treefrog would use the polyvinyl chloride (PVC) refuge (LR = 1.69, p = 0.19 for squirrel treefrogs and LR = 0.13, p = 0.72 for green treefrogs); both species of native treefrogs were observed sharing the refuge with Cuban treefrogs on multiple occasions
It is important for ecologists to evaluate indirect effects of invasive species on native species, as inter- and intraspecific interactions have the potential to influence both invasion success and impacts on native species

Summary

Introduction

Competition within and among species can limit their distribution and abundance [1,2]. Introduction of a novel species can greatly alter population and community dynamics through competition and, in some cases, cause trophic shifts, changes in population size-structure, and declines or local extinctions of native species [4,5,6]. Competitor introductions may result in niche shifts within the native community [7,8]; such shifts may merely delay, rather than prevent, the decline of the native species [9]. Predation is usually implicated as the primary cause of declines, but competition among Cuban treefrogs and native species for food and space may play a role. In laboratory experiments, Cuban treefrog tadpoles were superior competitors than tadpoles of several native species of frogs [13,14]

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