What to do with a (probably) Snowflake Bobwhite Quail?

This wee birdie turned up in our garden at the weekend and is still mooching about now.  I’ve asked around the village and local area, nobody is owning up to owning it but it appears to have been doing the rounds most summer and seems happy looking after itself.  As far as I can tell it’s likely a Snowflake Bobwhite Quail but I’m worried it won’t survive on its own through winter (we’re in West Oxfordshire).  Any advice as to what I should do, please?  I don’t want to traumatise it, but am aware I have zero experience in capturing birds!