Somewhat smaller than a sparrow (ca.
10 cm) and with a stocky build.
 The male is deep blue above, sides of head and neck are deep blue, and a prominent white patch runs from centre of throat, through breast to belly.
 
The amount of white on the brow and tail show clinal variation from West to East along the Himalayan foothills, which is sometimes taken to distinguish three races:
The western race from the western Himalayas has a distinctive white supercilium and white bases to the outer tail feathers.

The eastern race (Ficedula superciliaris aestigma) from the eastern Himalayas lacks distinct white patches.

The population from the south Assam hills (sometimes designated a third race cleta) completely lack any supercilium.

Usually singly, though sometimes in mixed hunting parties in the winter.
 Keeps largely to the low trees and bushes, feeding among the foliage canopy, not venturing much into the open.
Constantly jerks up its tail, often accompanied by fluffing of head feathers and trrr note, especially in proximity of nest.
 Diet is mainly insects.
Somewhat smaller than a sparrow (ca. 10 cm) and with a stocky build.  The male is deep blue above, sides of head and neck are deep blue, and a prominent white patch runs from centre of throat, through breast to belly.  
The amount of white on the brow and tail show clinal variation from West to East along the Himalayan foothills, which is sometimes taken to distinguish three races:
The western race from the western Himalayas has a distinctive white supercilium and white bases to the outer tail feathers.
The eastern race (Ficedula superciliaris aestigma) from the eastern Himalayas lacks distinct white patches.
The population from the south Assam hills (sometimes designated a third race cleta) completely lack any supercilium.
Usually singly, though sometimes in mixed hunting parties in the winter.  Keeps largely to the low trees and bushes, feeding among the foliage canopy, not venturing much into the open. Constantly jerks up its tail, often accompanied by fluffing of head feathers and trrr note, especially in proximity of nest.  Diet is mainly insects.
Ultramarine flycatcher