High Trophic Niche Overlap between a Native and Invasive Mink Does Not Drive Trophic Displacement of the Native Mink...

Area of Science:

• Ecology
• Conservation Biology
• Invasive Species Biology

Background:

• Invasive species pose significant threats to native ecosystems.
• Understanding interspecific competition is crucial for conservation efforts.
• The impact of invasive American mink (Neovison vison) on native European mink (Mustela lutreola) requires detailed investigation.

Purpose of the Study:

• To assess the dietary overlap and niche partitioning between invasive American mink and native European mink.
• To investigate the potential trophic displacement of European mink due to American mink invasion.
• To inform conservation strategies for the critically endangered European mink.

Main Methods:

• Analysis of isotopic composition (δ13C and δ15N) in mink tissues and prey.
• Quantification of trophic overlap using stable isotope data.
• Assessment of niche overlap during sympatric occurrence.

Main Results:

• Significant trophic overlap was observed between European mink and American mink when coexisting.
• Both mink species exhibited considerable individual dietary variation.
• No significant dietary shift was detected in European mink following the arrival of American mink.

Conclusions:

• High niche overlap indicates intense interspecific competition between the two mink species.
• The lack of dietary displacement suggests direct competition for resources.
• This competitive pressure poses a serious threat to the viability of European mink populations, highlighting urgent conservation needs.