Do invasive species perform better in their new ranges?

Area of Science:

• Ecology
• Evolutionary Biology
• Invasion Biology

Background:

• A core tenet of invasion biology posits that invasive species perform better in introduced ranges than native ranges.
• This assumption underpins many hypotheses explaining invasion success due to altered ecological and evolutionary pressures.
• Empirical data testing this fundamental assumption across diverse species are limited.

Purpose of the Study:

• To empirically test the widespread assumption of enhanced performance in invasive species.
• To compare organism size, reproductive output, and abundance of invasive species in introduced versus native ranges.
• To assess the universality of performance enhancement in invasive species.

Main Methods:

• Meta-analysis of published studies on invasive species.
• Included 26 plant and 27 animal species identified as invasive.
• Compared performance metrics (size, fecundity, abundance) between introduced and native populations.

Main Results:

• On average, invasive species showed increased size, fecundity, and abundance in introduced ranges.
• Significant interspecific variability was observed; approximately half of the studied species (27/53) showed similar performance across ranges.
• The pattern of enhanced performance in introduced ranges is not universal among invasive species.

Conclusions:

• The assumption of universally enhanced performance for invasive species is not supported by current data.
• While some invasive species do exhibit superior performance, many do not differ significantly from their native counterparts.
• Invasion success may be driven by factors beyond simple performance enhancement in the introduced range.