I mentioned these particular Bobwhites and perhaps that this also would be good location to re-introduce this game bird, as this is protected land and seems to be what Bobwhites need in terms of habitat.
He replied back to me the following:
As a follow up I talked to Audubon about your sighting and here is what they said:
"We have gotten calls on this too over the last year. Unfortunately, after we publicized the Pine Barrens project, someone at the US Coast Guard station over that way thought they would “help” by releasing pen raised birds in that area, not to mention releases of quail from the Quail in the Classroom project (once the birds were raised by the kids in an incubator and the school year was over they turned them loose out there) – so unfortunately no one knows what is wild(?) or pen raised now over there. Our feeling and for the most part NJDFW’s feeling its all pen raised. "
So that fits my hunch as well. Pen raised birds will occasionally breed and have offspring (as you have seen). However all the past research indicates they will have 0% survival over the winter and thus will not effectively recolonize an area.
So....given that information....one can assume that these are 'planted' and from where and by whom, is anyone's guess. Since this is a pretty easy place to get to, it will be interesting to monitor these Bobwhites and see if they do survive the winter. Right now, it would appear that there is at least one adult and three young. So will see.... I would be saddened if these Bobwhites didn't survive the winter, as they were just tossed into the wild without a chance. While people have the best intention of helping, it doesn't always work out that way.