Is it a Different Vermilion Flycatcher? Or has it Matured?

Vermilion Flycatchers (Pryocephalus rubinus) are rarely seen this far north. They are more common in subtropical environments like Southern California and Mexico. So their presence is enough to get local birders interested in having a look. 

Luckily, these are also birds of habit, migrating back to the same area year after year. One of the few ever seen in Stanislaus County returned to the same fence line for four years running, which is pretty much the known expected lifespan of these pretty birds.

The latest visitors have been sighted at the Merced National Wildlife Refuge in Merced County. We've been watching every fall for the female that likes to hang out on the west side of the auto-tour loop for at least three years so far (we saw it last fall, but others report that it is there this winter as well). On the southeast corner of the loop there has been a juvenile male for months now.

Except...is it the same bird? We caught the first three images above a week ago. The last three images are from late October at the same location. A couple of birders have suggested that there might be two individual males at the refuge right now, but no one has reported seeing both at once.

I'm no expert at the developing maturity of these birds. I don't know how quickly they develop the bright red plumage of adulthood. So I leave it to you...do these pictures represent one bird or two??