I see on the AZA's website that the wolf subspecies that is being focused on in the USA is the Mexican wolf. Are other subspecies also being managed or being phased out in favor of the Mexican wolf?
The others arent being phased out. They are just not managed by an SSP so they dont show up. They are either DERP (Display, Educational, Research Populations) or PMP (Population Management Plan which is just short of SSP). Zoos are welcomed to have, breed and swap them. It's just not as tightly managed as an SSP. The AZA website only posts SSP species and even then not all have been uploaded yet. Hope that helps.