Artificial illumination influences niche segregation in bats

Area of Science:

• Ecology
• Wildlife Conservation
• Environmental Science

Background:

• Artificial light at night (ALAN) is a growing environmental pollutant affecting ecosystems.
• Nocturnal bats, particularly, are impacted by ALAN, with some species exploiting it for foraging.
• Two pipistrelle bat species, Pipistrellus kuhlii and Pipistrellus pipistrellus, were studied in Italy where they recently became syntopic.

Purpose of the Study:

• To investigate how ALAN influences niche segregation and habitat preferences in two potentially competing pipistrelle bat species.
• To contrast the potential environmental preferences with the actual habitat use of Kuhl's and common pipistrelles in relation to ALAN.
• To understand the ecological interactions driven by light pollution between syntopic bat species.

Main Methods:

• Spatial modeling and species distribution models were used to analyze habitat preferences.
• Niche overlap analysis was performed to assess potential competition.
• Radiotracking was employed to study fine-scale habitat segregation and ALAN use.

Main Results:

• Both pipistrelle species showed a niche overlap and a preference for artificially illuminated areas.
• Pipistrellus kuhlii significantly increased its association with ALAN when P. pipistrellus was considered.
• Radiotracking revealed fine-scale habitat segregation, with P. kuhlii utilizing illuminated sites more than P. pipistrellus.

Conclusions:

• ALAN plays a crucial role in mediating niche segregation between competing bat species.
• Light pollution significantly affects species interactions and community dynamics.
• The study highlights complex ecological interactions arising from the interplay of light pollution and species' habitat preferences.