nominate in North America). Length 3.5–4"; bill 16–20 mm. Tail weakly graduated. Pale eye ring in all plumages. Adult male: rose-red gorget with pale chin and face. Often detected by wing trill.
The remaining male pup developed into a fertile adult male with the same agouti coat colour as the B6C3F1 tail-tip cell donor. As oocytes of B6D2F1 mice do not carry the agouti mutation ...