Heritability of cognitive performance in wild Western Australian magpies

Individual differences in cognitive performance can have genetic, social
and environmental components. Most research on the heritability of
cognitive traits comes from humans or captive non-human animals, whilst
less attention has been given to wild populations. Western Australian
magpies (Gymnorhina tibicen dorsalis, hereafter magpies) show phenotypic
variation in cognitive performance, which affects reproductive success.
Despite high levels of individual repeatability, we do not know whether
cognitive performance is heritable in this species. Here, we quantify
broad-sense heritability of associative learning ability in a wild
population of Western Australian magpies. Specifically, we explore whether
offspring associative learning performance is predicted by maternal
associative learning performance, or by the social environment (group
size) when tested at three time points during the first year of life. We
found no significant relationship between maternal and offspring
associative learning performance, with an estimated broad-sense
heritability of just -0.004 ± 0.024 (CI: -0.050/0.044). However,
complementing previous findings, we find that at 300 days post-fledging,
individuals raised in larger groups passed the test in fewer trials
compared to individuals from small groups. Our results highlight the
pivotal influence of the social environment on cognitive development.