Lufira Masked Weaver

This endemic resident occurs in swamps and riverine vegetation in the Lufira river valley in the vicinity of Lake Tshangalele in DR Congo.

The breeding season is from February to March; the male builds a elaborately woven nest for a female.

IUCN Red List Status: Data Deficient (DD)

The Lufira Masked Weaver is previously only known from the unique type specimen collected in 1960 at Lake Lufira (= Lake Tshangalele) in Katanga (Democratic Republic of Congo). For many years the status of Ploceus ruweti remained obscure, until it was rediscovered nesting at the same locality in February–March 2009.

The males of this sexually dimorphic ploceid are yellow and rufous coloured with a black mask differing from other members of the P. velatus complex by some detailed diagnostic characteristics.

• Males in breeding plumage are distinguished from Lesser, Southern and Katanga Masked Weavers P. intermedius, P. velatus and P. katangae by strong chestnut wash on breast and flanks. Similar to Tanganyika Masked Weaver P. reichardi but black on head of Lufira Masked Weaver P. ruweti extends to hind-crown (Oschadleus 2004). Golden-backed Weaver P. jacksoni is also very similar, but the black of the head reaches onto the nape (Louette & Hasson 2009). Some subspecies of Yellow-backed Weaver P. melanocephalus look similar too, but it has brownish irides, while all previously mentioned weavers have reddish irides.
• Vocalisations: mainly short calls, typical weaver sounds (Louette & Hasson 2009).

• Endemic resident (Oschadleus 2004), restricted to the Lufira valley in Katanga, south-eastern Democratic Republic of the Congo (Congo-Kinshasa): initially found to be restricted to Lake Lufira (= Lake Tshangalele), where it was common in 1960 when the type specimen was collected (BirdLife International 2008, Louette et al. 2002) and where it was rediscovered nesting at the same locality in February–March 2009 (Louette & Hasson 2009). In February 2010, a range extension is detected, because Ploceus ruweti was encountered nesting near Kiubo Falls some 120 km downstream on the Lufira River (Craig et al. 2011). Although observations from the intervening stretch of river are lacking, it seems probable that this weaver occurs elsewhere too.
• IUCN range map: http://maps.iucnredlist.org/map.html?id=106008524

Preliminary results reveal that Lufira Masked Weaver is a member of the P. velatus complex (Louette & Hasson 2009). Preliminary DNA sequence data of the mitochondrial cytochrome oxidase 1 gene (COI) show a low sequence divergence between P. ruweti on the one hand and several P. velatus sensu strictu (<1%) and P. jacksoni (<0.5%) on the other hand, as well as between P. velatus and P. jacksoni (<1%) (Craig et al. 2011). Interspecific sequence divergence between the P. ruweti/velatus/jacksoni group and other Ploceus species (including P. vitellinus uluensis, P. katangae, P. upembae and P. reichardi) are markedly higher (>2% up to 11%; unpublished data). Concerning the species status of Ploceus ruweti, the data available confirm that it is a valid species, since both P. jacksoni and P. velatus are morphologically and ecologically distinct, with entirely allopatric distribution ranges (Craig et al. 2011). Current comparative molecular studies by JEMU at the Royal Museum for Central Africa will hopefully clarify the relationships of these species within the genus Ploceus.

• In swamps bordering Lake Lufira, it occurs in reedbeds of Phragmites and Typha, interspersed with bushes and Sesbania leptocarpa (BirdLife International 2010), and also in the grass Vossia cuspidate (Louette & Hasson 2009). Nests are typically in ‘Ambatch’ Aeschynomene elaphroxylon trees above water, situated in the centre of the lake, close to the ancient riverbed (Louette & Hasson 2009). All breeding sites are along the original course of the Lufira River (Craig et al. 2011).
• In riverine vegetation near Kiubo Falls some 120 km downstream on the Lufira River, nests are found in Acacia trees over dry land adjoining cultivated fields with maize, peanuts, and cassava, but within 100 metres of the water’s edge (Craig et al. 2011).
• It is apparently less specialised in its habitat requirements than previously assumed, and it would seem misleading to categorize it as a “swamp-dwelling” species (cf. Louette & Benson 1982).
• Wetlands (inland): Shrub Dominated Wetlands, Bogs, Marshes, Swamps, Fens, Peatlands (BirdLife International 2008).

• Adult male in breeding plumage has a black head (from forehead to hind-crown and ear-coverts), pale lemon yellow nape, deep yellow (greenish streaked) back, yellow rump, dusky tail, greenish yellow belly and undertail-coverts, orange-chestnut breast and flanks, black chin, black bill, dark reddish irides and greyish-beige legs (Oschadleus 2004; Louette & Hasson 2009).
• Female is generally more greenish coloured without black and almost no rufous, (except for a brownish wash to the underparts in some individuals); two wingbars are apparent (Louette & Hasson 2009). The bill is brownish greyish, irides are dark brownish, legs horn brown (Craig et al. 2011).
• Fledgling has the nondescript plumage common to all small weavers (Louette & Hasson 2009).

Probably in the Lake Lufira valley between Lake Lufira and Kiubo Falls, although observations are lacking from the intervening stretch of river (Craig et al. 2011). Local inhabitants claim that the birds are observed away from the Lake Lufira in the latter half of the dry season, in July–October (Louette & Hasson 2009).

• The breeding season is from February to March (Louette & Hasson 2009).
• Colonies vary in size from three to 20 nests (Oschadleus 2004, BirdLife International 2008).
• Males are nest-building, and displaying at completed nests and incomplete nest frames (Craig et al. 2011): each male had more than one nest, although the few observations don’t allow to confirm polygyny.
• Birds normally raise two broods per breeding season (BirdLife International 2008).

• Length: circa 13 cm (Oschadleus 2004); males are usually larger than females in sexually dimorphic ploceids.
• Male: wing: 68,5-71,0 mm; tail: 45 mm; bill length to skull: 16 mm; tarsus: 20,5-21,0 mm (Oschadleus 2004, Louette & Hasson 2009).
• Female: wing: 63-65 mm; tail: 46-47 mm; bill length to feathers: 12,0-12,7 mm; tarsus: 18,5-19,1 mm; weight: 16,5-17,0 g (Craig et al. 2011).

Reportedly common in 1960 (within its tiny range in the vicinity of Lake Lufira), rediscovered nesting (at the same locality) in 2009 (Louette & Hasson 2009), and resighted (there as well as near Kiubo Falls) in 2010 (Craig et al. 2011)

The Lufira masked weaver (Ploceus ruweti), also known as Ruwet's masked weaver or the Lake Lufira weaver, is a species of bird in the weaver family, Ploceidae. It is endemic to the Democratic Republic of the Congo. Its natural habitat is swamps in the south-east part of the country. It is sometimes regarded as a subspecies of the Tanzanian masked weaver.