I think its a Eupeodes, but far from certain.
No interactions present.
for the identification. For some reason I convinced myself it wasn't a Syrphus.
I can understand why, as the black is broader than the yellow on each tergite. Dark variants like this are not that uncommon, though, and seem to occur in any of the species.
My Flickr photos...
I shall know next time. Hopefully...
Lat/Lng: 54.6215, -1.2545
OS grid ref: NZ482254