SUMMARYNoske, R. A. 1979. Co-existence of three species of treecreepers in north-eastern New South Wales. Emu 79: 120–128.The White-throatedClimacteris leucophaea, Red-browedC. erythropsand BrownC. picumnusTree- creepers are sympatric in south-eastern Australia. All three appear to feed largely on ants. I compared the ecology and behaviour of these birds in the non-breeding season of 1976 at Wollomombi Falls, forty kilo-metres east of Armidale, NSW. Here the three species occur in the same habitat and may be seen foraging on the same trees at the same time.The Brown spent almost half its time on the ground or on logs but the Red-browed and White-throated foraged almost entirely on trees. The last two species occurred at similar heights and on branches of similar sizes but on different types of trees and had different foraging techniques. The White-throated mostly foraged by pecking and excavating pieces of bark from rough-barked trees such as stringybarks. The Red-browed typically peered and probed into ribbons of bark hanging from smooth-barked trees such as Yellow BoxEucalyptus melliodora.These two species also differed in social organization; the White-throated was territorial and usually solitary but the Red-browed occurred in groups of three or four individuals.In aggressive encounters the larger Brown Treecreeper dominated the other two. The Red-browed always dominated the White-throated although these two species are similar in size.