Data from: Inbreeding influences within-brood heterozygosity-fitness correlations (HFCs) in an isolated passerine population

Molecular estimates of inbreeding may be made using genetic markers such
as microsatellites, however the interpretation of resulting
heterozygosity-fitness correlations (HFCs) with respect to inbreeding
depression is not straightforward. We investigated the relationship
between pedigree-determined inbreeding coefficients (f) and HFCs in a
closely monitored, reintroduced population of Stewart Island robins
(Petroica australis rakiura) on Ulva Island, New Zealand. Using a full
sibling design, we focused on differences in juvenile survival associated
specifically with individual sibling variation in standardized multilocus
heterozygosity (SH) when expected f was identical. We found that within
broods, siblings with higher SH at microsatellite loci experienced a
higher probability of juvenile survival. This effect, however, was
detected primarily within broods that experienced inbreeding or when
inbreeding had occurred in their pedigree histories (i.e., at the parents’
level). Thus we show, for the first time in a wild population, that the
strength of an HFC is partially dependent on the presence of inbreeding
events in the recent pedigree history. Our results illustrate the
importance of realized effects of inbreeding on genetic variation and
fitness and the value of full-sibling designs for the study of HFCs in the
context of small, inbred populations.