Bertram's weaver, sometimes called Bertrand's weaver, is a species of bird in the family Ploceidae. It is found in Malawi, Mozambique, Tanzania, and Zambia.
Region
Southeast Africa
Typical Environment
Occurs from southern Tanzania through Malawi to northern Mozambique and eastern Zambia, especially around the Lake Malawi basin. Favors riparian habitats including riverine forest edges, swamp-fringed thickets, and reedbeds. It also uses moist woodland (including miombo edges) and overgrown cultivation near water. The species is typically tied to dense cover and nest sites close to wetlands or slow-flowing rivers.
Altitude Range
Sea level to 1800 m
Climate Zone
Tropical
Ease of Keeping
Beginner friendly: 2/5
Bertram's weaver is a small East African weaver known for its finely woven, pendant nests, often placed over water or in dense riverside thickets. Males construct multiple nests as part of courtship, displaying actively to attract females. They often breed in loose colonies and take advantage of reeds and low trees for nesting sites.
Temperament
social and active
Flight Pattern
short rapid wingbeats
Social Behavior
Often forms small flocks outside the breeding season and gathers in loose colonies to nest. Males weave several pendant nests in reeds or low branches near water and display to passing females; polygyny occurs. Nests are suspended with side entrances, and females handle most incubation and chick care.
Migratory Pattern
Resident
Song Description
A busy series of buzzy chatters and squeaky trills delivered from conspicuous perches near the colony. Males vocalize persistently during nest-building and display, mixing harsh calls with thin, accelerating notes.
Plumage
Breeding males show bright yellow underparts with olive-green upperparts and a slightly dusky mask through the lores and ear-coverts; the bill is stout and dark. Females and non-breeding birds are duller olive-yellow with less contrast and faint streaking on the upperparts. Overall appearance is of a yellow weaver with olive tones and minimal wing patterning.
Diet
Takes a mixed diet of grass seeds and other small seeds, complemented by insects such as beetles, caterpillars, and spiders. During breeding it increases animal prey to meet protein demands. It also occasionally consumes small fruits or nectar when available.
Preferred Environment
Forages in dense thickets, reedbeds, river margins, and woodland edges, often close to water. It also uses overgrown gardens and farmland hedgerows, probing foliage and gleaning from stalks and leaves.
