02368nas a2200181   4500008004100000245016000041210006900201300001200270490000700282520162100289653003101910653002801941653002301969653001801992100001502010700002302025856013802048       2002                        eng d00aConfidence of paternity and paternal care: covariation revealed through the experimental manipulation of the mating system in the beetle Onthophagus taurus0 aConfidence of paternity and paternal care covariation revealed t  a784-7950 v153 aTheoretical models of paternal care predict that facultative reductions in male care may occur under certain conditions. One important parameter that has been shown to influence the outcome of these models is a male’s confidence of paternity. In this study, we tested whether the amount of care provided by horned males in the dimorphic beetle, Onthophagus taurus, varied with his confidence of paternity. Male care results in an increased weight of dung provided in the brood masses produced by the pair. Using the sterile male technique we showed that a horned male’s paternity declined with the number of sneak males in the population. The relationship was nonlinear, with paternity declining most rapidly between a frequency of one and three sneaks, and stabilizing thereafter at about 50%. A horned male’s paternity was directly related to the number of copulations with the female, relative to the number of copulations achieved by sneaks. Horned males were shown to reduce their care in relation to their declining paternity. Video analysis demonstrated that reductions in male care occurred through a combination of male desertion and a trade-off between caring and paternity assurance behaviours. The number of fights with sneak males was negatively related to the amount of care provided by a horned male. These results suggest that by gauging his expected paternity through the number of fights with sneaks, a horned male is able to assess his paternity and reduce his investment accordingly. Our data thus provide strong empirical support for the proposed link between paternity and paternal care. 10aalternative mating tactics10aconfidence of paternity10aOnthophagus taurus10apaternal care1 aHunt, John1 aSimmons, Leigh, W.  uhttps://scarabnet.myspecies.info/confidence-paternity-and-paternal-care-covariation-revealed-through-experimental-manipulation-mating