• Gross, Mart R.
  • University of Utah


In North American sunfishes (Lepomis: Centrarchidae) ♂♂ build nests and provide solitary parental care for the young. In this paper I provide for bluegill (L. macrocbirus) a detailed account of ♂♂ which do not build nests, but steal fertilizations from the nests of other ♂♂. I begin by giving data on the behavior, morphology, and population demography of ♂♂. Next, through an analysis of individual male life‐histories, I show that cuckoldry and parenting are discrete alternative reproductive strategies. This is followed by a theoretical analysis and an empirical test of cuckoldry and parental care as evolutionarily stable strategies (a mixed ESS). Several predictions are made concerning how natural selection will influence the life‐history dynamics of these strategies. A general theory is then developed for sunfishes, and a first test made on the pumpkinseed (L. gibbosus). Finally, I note the parallels between male cuckoldry in sunfishes and precocial male life‐histories in salmon and cichlids.