The black-headed weaver (Ploceus melanocephalus), also known as yellow-backed weaver, is a species of bird in the family Ploceidae. It is a resident breeder in damp areas in tropical Africa.
The black-headed weaver was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae under the binomial name Loxia melanocephala. He specified the type locality as Guinea. Linnaeus based his account on the "Gamboa Groasbeak" that had been described and illustrated in 1750 by the English naturalist Eleazar Albin in his book A Natural History of Birds. Albin had sketched a live specimen belonging to the Duke of Chandos at his country house, Cannons, which was located about northwest of London near Edgware. The specific epithet melanocephalus, melanocephala combines the Ancient Greek üõûñÃÂ/melas, üõûñýÿÃÂ/melanos meaning "black" with -úõÃÂñûÿÃÂ/-kephalos meaning "-headed". The black-headed weaver is now one of 67 species placed in the genus Ploceus that was introduced in 1816 by the French naturalist Georges Cuvier.
Five subspecies are recognised:
P. victoriae <small>Ash, 1986</small> is now thought to be a hybrid between P. melanocephalus and P. castanops.
Breeding males have a black head and yellow nuchal collar, which is absent in the Juba and golden-backed weavers. It also differs from the latter species and village weaver by its plain, greenish mantle plumage. The pale yellow underpart plumage is suffused with a variable amount of chestnut.
The female and non-breeding male lack the black head, and resemble a female masked weaver, except that they have dark eyes and a darker bill. Their buffy breast plumage also distinguishes them from non-breeding golden-backed weavers.
It is found in West, Central, and East Africa, but it has also been introduced to the Iberian Peninsula. It is found in savanna and similar habitats, typically near water. It often lives on an Acacia tree 3 meter away from land to prevent predation.