His bird records are frequently mentioned in the Natural History of Ireland by William Thompson.
He worked as a plant specimens collector for David Moore, John Scouler and Thomas Coulter.
McCalla collected algae and flowering plants, his records are included in Harvey's Phycologia Britannica.
An account of his life and career is given by Tim Robinson in Connemara:Listening to the Wind.
William McCalla was recognized for his publication, Algae Hibernicae, in 1845, by the Royal Dublin society, by a silver award medal.