From The Modern Encyclopedia, published in the early 1930s:
Bustard (Old Fr, bistarde; Lat. avis, bird; tarda, slow). Group of large, stoutly-built birds. The common bustard (otis tarda) was formerly common in Great Britain, but is now only occasionally found in the S. counties. Standing over 3ft. in height, it is a handsome mottled with grey, brown, and black. It lives mainly on corn and young shoots, but will also devour frogs and other small animals. The nest is merely a hollow in the ground.