Adults have characteristic red cap or “poll.” Polytypic. Length 5.3". The common is generally a relatively small, streaked finch with a ... a juvenile pine siskin, but it lacks yellow in ...

Male red siskins (Spinus cucullatus), a species of finch, flaunt orange-red bellies and backs ... at the University of Porto in Portugal had previously discovered that a siskin gene called CYP2J19 ...