GitHub repository containing R code and data for: "Little evidence of inbreeding depression for birth mass, survival and growth in Antarctic fur seal pups"

This Github repository contains the workflow necessary to run the analysis done in the manuscript "Little evidence of inbreeding depression for birth mass, survival and growth in Antarctic fur seal pups". For more details, see the readme file or the repository on Github.

Manuscript abstract

Inbreeding depression, the loss of offspring fitness due to consanguineous mating, is generally detrimental for individual performance and population viability.  We therefore investigated inbreeding effects in a declining population of Antarctic fur seals (Arctocephalus gazella) at Bird Island, South Georgia.  Here, localised warming has reduced the availability of the seal’s staple diet, Antarctic krill, leading to a temporal increase in the strength of selection against inbred offspring, which are increasingly failing to recruit into the adult breeding population.  However, it remains unclear whether selection operates before or after nutritional independence at weaning.  We therefore used microsatellite data from 885 pups and their mothers, and SNP array data from 98 mother-offspring pairs, to quantify the effects of individual and maternal inbreeding on three important neonatal fitness traits: birth mass, survival and growth.  We did not find any clear or consistent effects of offspring or maternal inbreeding on any of these traits.  This suggests that selection filters inbred individuals out of the population as juveniles during the time window between weaning and recruitment.  Our study brings into focus a poorly understood life-history stage and emphasises the importance of understanding the ecology and threats facing juvenile pinnipeds.

Funding

This research was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) priority programme “Antarctic Research with Comparative Investigations in Arctic Ice Areas” SPP 1158 (project number 424119118) and the SFB TRR 212 (NC³) (Project Numbers 316099922 & 396774617).  This work contributes to the Ecosystems project of the British Antarctic Survey, Natural Environmental Research Council, and is part of the Polar Science for Planet Earth Programme.