The common waxbill (Estrilda astrild ), also known as the St Helena waxbill, is a small passerine bird belonging to the estrildid finch family. It is native to sub-Saharan Africa but has been introduced to many other regions of the world and now has an estimated global extent of occurrence of 10,000,000 km2. It is popular and easy to keep in captivity.
It is a small bird, 4 to 5 inches in length with a wingspan of 4 1/2 inches and a weight of 3/5 to 3/4 ounce. It has a slender body with short rounded wings and a long graduated tail. The bright red bill of the adult is the colour of sealing wax giving the bird its name. The plumage is mostly grey-brown, finely barred with dark brown. There is a red stripe through the eye and the cheeks and throat are whitish. There is often a pinkish flush to the underparts and a reddish stripe along the centre of the belly depending on the subspecies. The rump is brown and the tail and vent are dark. Females are similar to the males but are paler with less red on the belly. Juveniles are duller with little or no red on the belly, fainter dark barring and a black bill.
Similar species include the black-rumped, crimson-rumped and black-lored waxbills. The black-rumped waxbill is black rather than brown on the rump and has a pale vent (area underneath the tail). The crimson-rumped waxbill has a dark bill, red rump and some red on the wings and tail. The black-lored waxbill (found only in the Democratic Republic of Congo) has a black rather than red stripe through the eye.
The common waxbill has a variety of twittering and buzzing calls and a distinctive high-pitched flight-call. The simple song is harsh and nasal and descends on the last note.