The Handbook of Birds of the world have just split Arabian Green Bee-eater from Green Bee-eater. Philothrus cyanophrys Cabanis and Heine, 1860, Arabia = mountains of Al Qunfudhah, southwestern Saudi Arabia. Usually treated as conspecific with M. viridissimus and M. orientalis, but differs from both in its very short stub-ended central tail feathers; bright blue forehead, supercilium and throat, and bluer lower belly; broader, smudgier black breast-bar; marginally larger size and clearly longer tail (minus the tail extensions) than the other taxa. Proposed race najdanus (from C Arabian plateau) now included within muscatensis.
Two subspecies currently recognized. M. c. cyanophrys from southern Israel, western Jordan and west & south Arabian coasts and M. c. muscatensis from central Arabian plateau and eastern Arabia (eastern Yemen to Oman and United Arab Emirates).
This makes it another Arabian endemic in their eyes, and in this instance the species is not difficult to see and can be seen away from the main endemic rich area of the southwest mountains, although it does not reach as far as the Eastern Province stopping around the Riyadh area in central Saudi Arabia.
I do not use HBW as my list but it will be interesting to see if anyone else adopts their reasoning.