I'm no expert, these birds teach me something everytime I spend time with them.
This is actually quite ironic. I have been spending time with what I thought was a single bird this last 3 weeks at a new location. I'm getting to know it, so it's all new to me regarding this place.
Anyway, had my 3rd outing there today, 6 hours in total. I got to photograph a single bird, what I think is a scruffy, possibly moulting juvenile female. Knowing how relatively large a single Kingfisher territory can be, a kilometer or more, I thought it was initially a single adult as the breeding season is coming to an end now. Today though, my thoughts changed when I photographed this bird, it's obviously a juvenile from some point this year. Just to note, KFs will have up to 3 broods a year, starting in February through to September, even into October if the weather is mild enough.
Today though, there was obviously more than one bird, in addition to the one I photographed. I'm guessing 4 dispersing juveniles but it could also have been juveniles being chasesd away by adults. Apart from the one I photographed, they were all too far away, albeit only 30 feet or so to sex or age.
This might be the case with Rick's (OP) birds too, adults chasing juveniles away or could be dispersing juveniles.
I really doubt 4 will hang around, they will be dispersing soon and one adult (usually) will remain and hold the territory over the wintner months. It will defend it it vigorously as food will soon be at a premium.