Competitive displacement and agonistic character displacement, or the ghost of interference competition

McEachin, Shawn; Drury, Jonathan P.; Grether, Gregory F.

Abstract

Interference competition can drive species apart in habitat use through competitive displacement in ecological time and agonistic character displacement (ACD) over evolutionary time. As predicted by ACD theory, sympatric species of rubyspot damselflies (Hetaerina spp.) that respond more aggressively to each other in staged encounters differ more in microhabitat use. However, the same pattern could arise from competitive displacement, if dominant species actively exclude subordinate species from preferred microhabitats. The degree to which habitat partitioning is caused by competitive displacement can be assessed with removal experiments. We carried out removal experiments with three species pairs of rubyspot damselflies. With competitive displacement, removing dominant species should allow subordinate species to shift into the dominant species’ microhabitat. Instead, we found that species-specific microhabitat use persisted after the experimental removals. Thus, the previously documented association between heterospecific aggression and microhabitat partitioning in this genus is most likely a product of divergence in habitat preferences caused by interference competition in the evolutionary past.

Citation

McEachin, S., Drury, J. P., & Grether, G. F. (2023). Competitive displacement and agonistic character displacement, or the ghost of interference competition. The American Naturalist, https://doi.org/10.1086/728671

• Journal Article Type: Article
• Acceptance Date: Sep 23, 2023
• Online Publication Date: Nov 10, 2023
• Publication Date: 2023
• Deposit Date: Nov 24, 2023
• Publicly Available Date: Nov 11, 2024
• Journal: The American Naturalist
• Print ISSN: 0003-0147
• Electronic ISSN: 1537-5323
• Publisher: The University of Chicago Press
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1086/728671
• Public URL: https://durham-repository.worktribe.com/output/1949700