Correction to: Communications Biology https://doi.org/10.1038/s42003-019-0574-4, published online 13 September 2019.

In the original published version of the article, the Mapping section of the Methods incorrectly read “Trimmed reads were mapped to the brown bear (Ursus arctos) reference genome assembly (GCF_000687225.1)62 using HISAT2 (version 2.1.0)63.” The correct genome assembly reference for Ursus arctos is GCF_003584765.1 (reference 25). In addition, the following text was added: “we also mapped the reads to the polar bear (Ursus maritimus) reference genome assembly (GCF_000687225.1)62 and results were consistent”. The error has been corrected in the HTML and PDF versions of the paper.