Unless there's a good reason to keep them, please disable build of static libs, otherwise provide USE="static-libs".
commit d6b76760fc1e569897865e04d3a9fdf3898a435c Author: Michał Górny <mgorny@gentoo.org> AuthorDate: Wed Aug 9 07:22:33 2017 Commit: Michał Górny <mgorny@gentoo.org> CommitDate: Fri Aug 11 15:20:38 2017 media-libs/libtiger: Disable static libraries