Behavioral Ecology and Sociobiology

, Volume 65, Issue 5, pp 995–1005 | Cite as

Alternative mating tactics in dimorphic males of the harvestman Longiperna concolor (Arachnida: Opiliones)

  • Camila Zatz
  • Rachel M. Werneck
  • Rogelio Macías-Ordóñez
  • Glauco MachadoEmail author
Original Paper


Intense male–male competition for females may drive the evolution of male morphological dimorphism, which is frequently associated with alternative mating tactics. Using modern techniques for the detection of discontinuous allometries, we describe male dimorphism in the Neotropical harvestman Longiperna concolor, the males of which use their elongated, sexually dimorphic legs IV in fights for the possession of territories where females lay eggs. We also tested three predictions related to the existence of alternative mating tactics: (1) if individuals with relatively longer legs IV (majors) are more likely to monopolize access to reproductive resources, they are expected to remain close to stable groups of females more than individuals with relatively shorter legs IV (minors) do; (2) if minors achieve fertilization by moving between territories, they are expected to be less faithful to specific sites; and (3) majors should be observed in aggressive interactions more often. We individually marked all the individuals from a population of Longiperna during the reproductive season and recorded the location of each sighting for males and females as well as the identity of males involved in fights. Majors were more likely to have harems, and large majors were even more likely to do so. Majors were more philopatric and all males involved in fights belonged to this morph. These results strongly suggest that the mating tactic of the majors is based on resource defense whereas that of the minors probably relies on sneaking into the territories of the majors and furtively copulating with females.


Discontinuous allometry Fight Male–male competition Mating system Polyphenism 



We are grateful to the staff of the Intervales State Park for logistical support, to many friends for helping with the fieldwork, to R. Knell, R. Munguía Steyer and R. Guevara for helping with the statistical analyses, to B.A. Buzatto, R. Munguía Steyer, E. Costa-Schmidt, P.S. Santos Filho, A. Eterovic, P.E.C. Peixoto, and three anonymous reviewers for comments on the manuscript, and to B.A. Buzatto for some of the photos used in Fig. 1. The specimens were identified by R. Pinto-da-Rocha, curator of the arachnological collection at the Museu de Zoologia da Universidade de São Paulo (MZSP) where voucher specimens were deposited. CZ and RMW have student grants from the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP 07/56841-2; 09/09453-2), GM has research grants from FAPESP (no. 02/00381-0; 09/50031-4; 08/06604-7) and from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), and RMO is supported by the Instituto de Ecología, A.C.


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Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Camila Zatz
    • 1
  • Rachel M. Werneck
    • 1
  • Rogelio Macías-Ordóñez
    • 2
  • Glauco Machado
    • 3
    Email author
  1. 1.Programa de Pós-graduação em Ecologia, Departamento de Ecologia, Instituto de BiociênciasUniversidade de São PauloSão PauloBrazil
  2. 2.Departamento de Biología EvolutivaInstituto de EcologíaVeracruzMexico
  3. 3.Departamento de Ecologia, Instituto de BiociênciasUniversidade de São PauloSão PauloBrazil

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