Ecological sexual dimorphism is modulated by the spatial scale of intersexual resource competition

Greta Bocedi* (Corresponding Author)

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Ecological sexual dimorphism, that is differences between the sexes in traits that are naturally selected as opposed to sexually selected, is gaining increasing attention after having often been dismissed as the ‘less-parsimonious’ explanation for differences between sexes. One potential driver of ecological sexual dimorphism is intersexual resource competition, in a process analogous to ecological character displacement between species; yet, clear empirical examples are scarce. Li and Kokko present mathematical models that introduce novel pieces to the puzzle: the role of the scale of mating competition and the spatial variation in resource availability. They show that ecological sexual dimorphism evolves when local mating groups are small (e.g. monogamous pairs) and when different resources are homogeneously available across habitats. Counterintuitively, larger mating groups (e.g. polygyny), and consequently higher intralocus sexual conflict, lead to sexual monomorphism. Habitat heterogeneity also leads to overlapping niches, although it can sometimes drive polymorphism within sexes. This study highlights why the conditions for intrasexual resource competition to drive evolution of sexual dimorphism are stringent, even in the absence of genetic constraints or competing species. Crucially, it highlights the importance of considering the mating system and the spatial scale of resource competition for understanding the occurrence of ecological sexual dimorphism, showing a large potential for future work considering different aspects of species’ life histories and spatial dynamics.
Original languageEnglish
Pages (from-to)1810-1813
Number of pages4
JournalJournal of Animal Ecology
Issue number8
Early online date3 Aug 2021
Publication statusPublished - 3 Aug 2021


  • ecological character displacement
  • intrasexual resource competition
  • mating system
  • niche partitioning
  • polymorphism
  • sexual conflict
  • sexual dimorphism
  • spatial heterogeneity


Dive into the research topics of 'Ecological sexual dimorphism is modulated by the spatial scale of intersexual resource competition'. Together they form a unique fingerprint.

Cite this