¹Department of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland

Correspondence: Ms M Saastamoinen, Department of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, PO Box 65, Helsinki FIN-00014, Finland. E-mail: marjo.saastamoinen@helsinki.fi

Received 27 March 2007; Revised 6 August 2007; Accepted 7 August 2007; Published online 5 September 2007.

Abstract

Knowing the variances and heritabilities (h²) of life history traits in populations living under natural conditions is necessary for a mechanistic understanding of respective evolutionary processes. I estimated heritabilities of several life history traits, including dispersal rate, body mass, age at first reproduction, egg mass, clutch size and lifetime reproductive success, in the Glanville fritillary butterfly (Melitaea cinxia) using parent–offspring regression. Experiments were conducted under field conditions in a large population cage (32 26 m). Heritability estimates ranged from zero to almost one and several were significantly different from zero. Body size for both sexes, female age at first reproduction and egg weight were all moderately to highly heritable, whereas heritabilities were low or non-existent in clutch size and lifetime egg production. Heritability estimates for dispersal rate varied between the sexes, so that dispersal was heritable from mother to her female offspring only. This finding is consistent with previous results showing that the F1 female but not male offspring of females that naturally established new populations in the field are significantly more dispersive than butterflies in old populations.