Interspecific aggression and character displacement in the damselfly Calopteryx splendens

Agonistic character displacement (ACD) occurs when selection to avoid maladaptive interspecific aggression leads to the evolution of agonistic signals and/or associated behavioural biases in sympatry. Here, we test for a pattern consistent with ACD in male colour pattern in darters (Percidae: Etheostoma ). Male colour pattern has been shown to function in male–male competition rather than female mating preferences in several darter species. Additionally, males bias their aggression towards conspecific over heterospecific males in sympatry but not in allopatry, consistent with divergent ACD in male behavioural biases. We use a common garden approach to show that differences in male colour pattern among four closely related darter species are genetically based. Additionally, we demonstrate that some aspects of male colour pattern exhibit enhanced differences in sympatric compared to allopatric populations of two darter species, consistent with ACD. However, other male colour traits are more similar between species in sympatry compared with allopatry, indicating that not all signal components are under strong divergent selection in sympatry. This study provides evidence that interspecific male–male aggressive interactions alone can promote elaborate male signal evolution both between and within species. We discuss the implications this has for male-driven ACD and cascade ACD.

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Interspecific aggression and character displacement of competitor recognition in Hetaerina damselflies

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2009.1371 ◽

2009 ◽

Vol 277 (1681) ◽

pp. 549-555 ◽

Cited By ~ 72

Author(s):

Christopher N. Anderson ◽

Gregory F. Grether

Keyword(s):

Character Displacement ◽

Interspecific Aggression ◽

Competitor Recognition

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Interspecific aggression, not interspecific mating, drives character displacement in the wing coloration of male rubyspot damselflies ( Hetaerina )

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2014.1737 ◽

2014 ◽

Vol 281 (1796) ◽

pp. 20141737 ◽

Cited By ~ 21

Author(s):

J. P. Drury ◽

G. F. Grether

Keyword(s):

Species Interactions ◽

Mate Recognition ◽

Character Displacement ◽

Interspecific Mating ◽

Reproductive Character Displacement ◽

Interspecific Aggression ◽

Female Mate ◽

Male Wing ◽

Competitor Recognition ◽

Wing Coloration

Traits that mediate intraspecific social interactions may overlap in closely related sympatric species, resulting in costly between-species interactions. Such interactions have principally interested investigators studying the evolution of reproductive isolation via reproductive character displacement (RCD) or reinforcement, yet in addition to reproductive interference, interspecific trait overlap can lead to costly between-species aggression. Previous research on rubyspot damselflies ( Hetaerina spp.) demonstrated that sympatric shifts in male wing colour patterns and competitor recognition reduce interspecific aggression, supporting the hypothesis that agonistic character displacement (ACD) drove trait shifts. However, a recent theoretical model shows that RCD overshadows ACD if the same male trait is used for both female mate recognition and male competitor recognition. To determine whether female mate recognition is based on male wing coloration in Hetaerina , we conducted a phenotype manipulation experiment. Compared to control males, male H. americana with wings manipulated to resemble a sympatric congener ( H. titia ) suffered no reduction in mating success. Thus, female mate recognition is not based on species differences in male wing coloration. Experimental males did, however, experience higher interspecific fighting rates and reduced survival compared to controls. These results greatly strengthen the case for ACD and highlight the mechanistic distinction between ACD and RCD.

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