Courting danger: socially dominant fish adjust their escape behavior and compensate for increased conspicuousness to avian predators

Males of many species display conspicuous colors to attract mates and deter rivals, although this benefit can incur an increased predation risk. In the African cichlid fish, Astatotilapia burtoni, males can change both their social status (dominant, DOM, or subordinate, SUB) and primary body color (yellow or blue). We hypothesized that these phenotypes vary in conspicuousness to predators and conspecifics, thus establishing a trade-off between intraspecific signaling and predation. We quantified the spectral reflectance of yellow and blue DOM and SUB males. We then constructed avian and conspecific visual receiver models to determine the relative conspicuousness of each phenotype. We show that there are significant differences in conspicuousness to predators and conspecifics, with the flanks of the yellow DOM males exhibiting more spectral contrast to both avian predators and conspecifics than the flanks of blue DOM males. Our measurements of escape behavior revealed that each morph exhibits distinct anti-predatory responses, with SUB males shoaling for protection, and the more conspicuous yellow DOM males executing more escape responses, potentially compensating for their increased conspicuousness. Our results suggest a novel mechanism for the maintenance of alternative male phenotypes in this species, where dynamically enhanced conspicuousness is offset by plastic changes in behavior.

Automated summary

The study found that in African cichlid fish, yellow dominant males exhibit higher spectral contrast when signaling to predators and conspecifics compared to blue dominant males. Different male phenotypes show distinct anti-predatory responses, with subordinate males shoaling for protection, and the more conspicuous yellow dominant males executing more escape responses. This suggests a novel mechanism where enhanced conspicuousness in certain male phenotypes is balanced by plastic changes in behavior.