Convergent morphology and divergent phenology promote the coexistence of Morpho butterfly species

The coexistence of closely-related species in sympatry is puzzling because ecological niche proximity imposes strong competition and reproductive interference. A striking example is the widespread wing pattern convergence of several blue-banded Morpho butterfly species with overlapping ranges of distribution. Here we perform a series of field experiments using flying Morpho dummies placed in a natural habitat. We show that similarity in wing colour pattern indeed leads to interspecific territoriality and courtship among sympatric species. In spite of such behavioural interference, demographic inference from genomic data shows that sympatric closely-related Morpho species are genetically isolated. Mark-recapture experiments in the two most closely-related species unravel a strong temporal segregation in patrolling activity of males. Such divergence in phenology reduces the costs of reproductive interference while simultaneously preserving the benefits of convergence in non-reproductive traits in response to common ecological pressures. Henceforth, the evolution of multiple traits may favour species diversification in sympatry by partitioning niche in different dimensions. 'Here, the authors use dummies of different Morpho butterfly species and sexes to investigate behaviour in patrolling butterflies, finding strong reproductive interference between species despite limited gene flow. They finally show that interference is mitigated by temporal partitioning, hence promoting the coexistence of sympatric Morpho species.'

Automated summary

Using dummy Morpho butterfly species and sexes, the authors found strong reproductive interference between species despite limited gene flow. They demonstrated that interference is mitigated by temporal partitioning, promoting the coexistence of sympatric Morpho species.