Resource defense polygyny shifts to female defense polygyny over the course of the reproductive season of a Neotropical harvestman

Bruno A. Buzatto, Glauco Machado*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

39 Citations (Scopus)


Although studies classify the polygynous mating system of a given species into female defense polygyny (FDP) or resource defense polygyny (RDP), the boundary between these two categories is often slight. Males of some species may even shift between these two types of polygyny in response to temporal variation in social and environmental conditions. Here, we examine the mating system of the Neotropical harvestman Acutisoma proximum and, in order to assess if mate acquisition in males corresponds to FDP or RDP, we tested four contrasting predictions derived from the mating system theory. At the beginning of the reproductive season, males fight with other males for the possession of territories on the vegetation where females will later oviposit, as expected in RDP. Females present a marked preference for specific host plant species, and males establish their territories in areas where these host plants are specially abundant, which is also expected in RDP. Later in the reproductive season, males reduce their patrolling activity and focus on defending individual females that are ovipositing inside their territories, as what occurs in FDP. This is the first described case of an arachnid that exhibits a shift in mating system over the reproductive season, revealing that we should be cautious when defining the mating system of a species based on few observations concentrated in a brief period.

Original languageEnglish
Pages (from-to)85-94
Number of pages10
JournalBehavioral Ecology and Sociobiology
Issue number1
Publication statusPublished - Nov 2008
Externally publishedYes


  • Gonyleptidae
  • Harem
  • host plant selection
  • male territoriality
  • Opiliones
  • resource holding potential
  • resource value

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