I enjoyed painting this one. I mixed burnt sienna, cadmium orange and transparent yellow to create the tawny orange colour for the head feathers. Olive Warblers are about 13 - 14 cm long and found from Southern Arizona and New Mexico in the USA, south to Mexico and Nicaragua.
Olive Warbler measures 3.5 x 2.5 inches and is painted on 300gsm smooth Arches watercolour paper.
Many thanks to Ron Knight for the reference photo.