The weebill (Smicrornis brevirostris) is Australia's smallest bird at approximately 8 to 9 cm (3.1 to 3.5 in) long. It is an olive-yellow songbird with a grey bill, brown wings, pale yellow eyes and grey feet. Its tail feathers are brown with a black bar and white spot on the tip of all inner webs but the central pairs. The sexes are similar. The weebill is the only member of genus Smicrornis; gene flow is strong and local variation follows Bergmann's and Gloger's Rules.