SummaryLenz, M. (1990). The breeding bird communities of three Canberra suburbs.Emu90, 145–153.The composition and size of the breeding bird populations of three plots with garden city character in Canberra, Australian Capital Territory, were each estimated for one breeding season between 1978 and 1981 using the modified territory mapping method. The number of territories per 10 ha (abundance) were 58.4 (Ainslie). 56.1 (Hackett) and 91.2 (Aranda). Species numbers in the sample areas were 26 (Ainslie, Hackett) and 20 (Aranda). Territories of introduced species, mainly House SparrowPasser domesticus(44.8–63.5%), Common StarlingSturnus vulgaris(6.8–23.0%) and BlackbirdTurdus merula(1.27.6%), comprised between 71–79% of the total number of territories. The only dominant native bird species was the SilvereyeZosterops lateralis(5.9–10.3%). 40–69% of all bird species ranked as rare (each<1 % of the total population). The abundances of native bird species, excluding the Silvereye, were 5.9 T/10 ha in Ainslie, 8.5 T/10 ha in Hackett and 18.9 T/10 ha in Aranda, probably reflecting the extent of native trees and shrubs in streets and gardens. In Ainslie, the vegetation was composed largely of exotic species. In Hackett, native trees (eucalypts) were more common but distributed unevenly. In Aranda, native vegetation dominated, many trees had been retained from the original woodland. Aranda supported a significantly higher population of exotic birds (65 T/10 ha) than Ainslie (46.5 T/10 ha) and Hackett (44.2 T/10 ha); many cavities in the original eucalypts provided House Sparrows and Common Starlings with more nest sites than were available in the other plots.