Published in HBW Volume 13 on page 695 (below).
Original HBW caption:
Bathing is an important routine, helping to rid the feathers of parasites. Most birds wishing to bathe approach the water source from ground level. The Eurasian Golden Oriole, however, frequently bathes by plummeting steeply from a nearby perch, splashing briefly into the water, and then heading rapidly to a tree or bush. This oriole also behaves like swallows (Hirundinidae) by gliding over water and briefly dipping in its underparts.