Summary
Various genetic and environmental variance components of cold resistance and oxygen consumption at rest of freshly emerged workers of the Cape honeybee Apis mellifera capensis were estimated. Estimates for heritabilities from a sib-analysis (hr2 = 0·37–0·41) were considerably larger than from a parent-offspring regression (hr2 = 0·13–0·15) or the estimate of the realized heritability (h2real, = 0·13–0·2). Effects of common hive environment are the most likely cause for this bias in the estimate of hs2.