Just to confuse the issue a bit further, spinoletta was split into three
species: Water Pipit (Anthus spinoletta), Rock Pipit (Anthus petrosus),
and American Pipit (Anthus rubescens). I think the split was about 12
or 15 years ago, since I think the "Water Pipits" I saw in England in
the late 80's were still conspecific with our pipits (which at one point
were also called "Water Pipits" - if I remember correctly).
The Brits refer to our bird as Buff-bellied Pipit, a nice name giving
recognition to the bright plumage they have in fall. And there is a
Siberian race (japonicus) as well - generally much darker than our bird,
at least in late summer and fall.
Lots of material in Handbook of Bird Identification for Europe and the
Westaen Palearctic, including superb plates!
Not an expert by any means but couldn't resist a discussion of
pipits. Frederick Pratt aka Pipit.