Non-behavioural interference competition between anuran larvae under semi-natural conditions.

Area of Science:

• Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Indirect competition in natural communities includes resource scramble and interference.
• Interference competition is challenging to demonstrate in field settings.
• Larval anurans, specifically Bufo bufo and Bufo calamita, exhibit strong competition, with B. bufo generally being the superior competitor.

Purpose of the Study:

• To investigate if interference competition between Bufo bufo and Bufo calamita larvae is detectable in natural pond environments.
• To assess the role of Anurofeca richardsi in mediating interference competition under natural conditions.

Main Methods:

• Larvae were reared at natural densities in cages within a sand dune pool.
• Experimental conditions included no interaction, partial interaction (mesh separation to allow chemical cues but prevent physical contact), and full interaction.
• Survival, growth rates, Anurofeca richardsi numbers, food acquisition, and food availability were measured.

Main Results:

• Asymmetric interspecific competition negatively affected B. calamita survival and growth under both full and partial interaction conditions.
• Competition strength was greater under full interaction compared to partial interaction.
• Interference competition, potentially mediated by A. richardsi, was evident in the partial interaction treatments where resource competition was excluded.

Conclusions:

• Interference competition between anuran larvae can occur and be detected in natural pond settings.
• Anurofeca richardsi plays a role in mediating this interference competition.
• Understanding interference competition is crucial for comprehending ecological dynamics in natural communities.