The relationships of many pheasants and partridges are still very badly resolved and much confounded by adaptive radiation (in the former) and convergent evolution (in the latter).^[10] Thus, the bulk of the Phasianidae can alternatively be treated as a single subfamily Phasianinae. The grouse, turkeys, true pheasants, etc., would then become tribes of this subfamily, similar to how the Coturnicinae are commonly split into a quail and a spurfowl tribe.^[11]

The partridge of Europe is not closely related to other partridge-like Galliformes, as already indicated by its sexually dimorphic coloration and possession of more than 14 rectrices, traits it shares with the other advanced phasianids. However, among these its relationships are obscure; it is unclear whether it is closer to the turkeys or to certain short-tailed pheasants like Ithaginis, Lophophorus, Pucrasia, and Tragopan.^[12]

Phylogeny

Living Galliformes based on the work by John Boyd.^[13]