Really Weird Red Crane

According to the Cornell Labs of Ornithology, ' Juvenile Sandhill Cranes have mostly rusty brown upperparts and gray underparts, with no red cap,'  This family photo obviously includes a younger bird.

Actually, ALL Sandhill Cranes are rust colored in the summer months, and they have patches of rust colored feathers all year round.  Usually, however, Sandhill Cranes are mostly gray in the winter months, except for their red crowns.

So, what is the story with this strange looking crane on the right?  It's no juvenile, because it clearly has a red crown.  But it is very different looking then the other 9,999 cranes we saw that day.  (Actually, I might be exaggerating a bit.  I think I saw two of these red cranes out of the 10,000 cranes there!)

He flies just like the other Sandhills.

He looks pretty much like a summer Sandhill Crane, but I still can't figure out why he isn't gray like all the rest.  Any ideas?