Roller (Harz Roller)
A variant of Domestic canary (Serinus canaria forma domestica)
Representative Domestic canaryphoto — a dedicated image of this exact morph isn't available yet.
A song canary bred in Germany for a soft, rolling, closed-beak song delivered in 'tours.' Judged entirely by ear, not by looks.
Keeper tips for this variant
Song is learned, so house young cocks within earshot of a proven 'schoolmaster' roller and keep them apart from harsh-singing breeds (like timbrados) so they don't pick up faulty tours.