Ploceus intermedius

Dove, Carla J., Saucier, Jacob, Whatton, James F., Schmidt, Brian & Roble, Houssein R., 2017, First record of River Warbler Locustella fluviatilis and additional records for Plain Nightjar Caprimulgus inornatus and Lesser Masked Weaver Ploceus intermedius in Djibouti, Bulletin of the British Ornithologists’ Club 137 (1), pp. 67-70 : 68-70

LESSER MASKED WEAVER Ploceus intermedius

A male was mist-netted on 5 February 2016 at Camp Lemonnier in an area of Prosopis sp. scrub near the east end of the installation. The bird (USNM 653247) was photographed ( Fig. 1 ) and prepared as a skeleton (feathers saved) because it represents the only osteological specimen of the species in the Smithsonian collection. The testes were not enlarged (2 × 1 mm), there was no bursa present, the skull was 100% pneumatized, and the bird was undergoing head and scattered body moult. Body mass was 18.1 g and trace fat was observed. Ash & Atkins (2009) indicated that the species is known (without evidence of breeding) from a cluster of tetrads close to the Djibouti border in Ethiopia, from where its distribution extends mainly along the Rift Valley . Ash & Miskell (1998) reported a breeding pair in northern Somalia among a colony of Rüppell’s Weavers P. galbula and our bird was mist-netted with several of the last-named species. We only observed this single individual during the winter survey of 2016. Prior to this, Welch & Welch (1992) observed a male building a nest on 26 March 1987 near the small town of Ἀs Ἑla (11 o 00’N, 42 o 06’E; 255 m elevation) in far southern Dikhil Region (132 km south-west of Djibouti City near the border with Ethiopia) and Laurent (1990) reported three nests on 28 December 1989 at the same location. Ours is the first specimen record of Lesser Masked Weaver for Djibouti, and is morphologically consistent with nominate P. i. intermedius in having an orange-chestnut hindcrown and yellow nape ( Fig. 1 ).

The date of collection (5 February) and the fact the bird was an adult (skull ossified) male moulting from non-breeding (eclipse) into breeding (nuptial) plumage may shed light on the status of the species in Djibouti. In most dimorphic Ploceidae, the male does not moult into breeding plumage until at least two years of age at which point they alternate between breeding and non-breeding plumages (Fry & Keith 2004). One of the males (USNM 247367) in the Smithsonian’s collection from Sadi Malk (near modern-day Awash, Ethiopia, c. 450 km south-west of Camp Lemonnier) was collected on 31 January 1912, during the Child’s Frick Expedition, by Edgar Mearns and exhibits less advanced adult plumage on the head and throat than our specimen.

The species is presumed resident where it occurs, and details of movements away from breeding areas are not well described. The greatest recorded distance travelled by a ringed individual was 74 km in South Africa (Craig 2010). Craig (2010) considered the species to be a wet-season visitor to South Sudan (rainy season mainly May–October), but given the distance it is unlikely that our specimen was headed there. In Ethiopia it is a locally very common breeding resident (Ash & Atkins 2009).

Unless it is discovered to be a longer distance migrant in the future, this specimen further documents this species presence in or very near Djibouti and underscores the need to better document the movements and breeding status of Lesser Masked Weaver.

Our surveys of Camp Lemonnier in 2014 and 2016 were very brief and represent only two short seasonal snapshots of the area’s biodiversity. However, our observations indicate that the area is under-studied and in need of additional surveys over longer time periods to more completely document the biodiversity of Djibouti. Given the rapid growth of this region in the Horn of Africa for military and commerce purposes, detailed biodiversity surveys should be a priority before critical conservation areas are designated for development.

Figures

Figure 1. Male Lesser Masked Weaver Ploceus intermedius, Camp Lemonnier, Djibouti, 5 February 2016, in the late stages of definitive moult showing orange-chestnut hindcrown feathers and diagnostic creamy-white eye (Carla J. Dove)