Sitta frontalis Swainson, 1820
Although Greenway (1967: 142) lumped the entire population of the Indian sub-continent, including Sri Lanka, and of Yunnan and the Indo-Chinese countries in nominate frontalis , and included Java and Sumatra in this form, he accepted saturatior Hartert, 1902, from the Malay Peninsula and northern Sumatra. This left frontalis with two disjunct populations and saturatior interposed between the two. Mees (1986), with admittedly limited material, and none from the Malay Peninsula, disagreed. He found adult Javan birds to have greyish-lilac underparts that differed from the browner tone of the nominate form. He thus brought the name velata Temminck, 1821, into use for the Javan population. In placing all Sumatran birds with those of Sri-Lanka he implied that saturatior should be seen as a synonym of the nominate form. But van Marle & Voous (1988) retained the treatment of Greenway and perhaps did not see the conclusions of Mees in time to consider them. Wells (in press) considers birds of the Malay Peninsula are distinct, intergrading with nominate frontalis in the north of the Peninsula. But the situation in Sumatra also needs to be re-examined
Variation within the Indian subcontinent was much discussed by Vaurie (1950), and the latter’s placement of corallina Hodgson, 1837, and simplex Koelz, 1939, in synonymy was accepted by Ripley (1961, 1982) as well as by Greenway.
It is uncertain where species limits lie. Many years ago I questioned whether solangiae was a species separate from frontalis. H.G. Deignan (in litt., 6 September 1965) replied: ‘Sitta frontalis and Sitta solangiae are certainly distinct, sympatric species! In Washington we have specimens of both shot out of the same flock on the same tree in the Lang Bian Highlands.’ Robson et al. (1993), who taped the call of solangiae , could not quite corroborate this, reporting Sitta frontalis at 1350 m at Da Tan la just south of Da Lat and Sitta solangiae on Mt. Lang Bian and at Cong Troi, southern Annam at 1750 m which convinced him that the two were separate species though perhaps altitudinally allopatric.