Born in Edinburgh, Alexander was predominantly renowned for his animal and bird paintings but he also made several studies of flowers and grasses. A visit to Tangiers with Joseph Crawhall when he was seventeen had a profound influence on his artistic career. During a long stay in Egypt he lived simply among the Arabs painting many watercolours of Arab tents and donkeys. He avoided the famous views of Egypt, painting instead the desert stretching into the distance, or grasses along the Nile.
His marriage in 1904 led him to settle in Inveresk from where he made frequent trips to the west coast to paint. His mastery of bird, flower and animal paintings can be explained by the exotic birds he kept in his garden and his sketching trips to the zoo. His technique was unusual, often working with sugar paper, linen or rough cardboard. His work, always decorative, shows the restraint practised by Crawhall, and he is justifiably recognised as one of Scotland's finest animal painters of his period.