Justification of Red List Category
This species is listed as Vulnerable because field studies have revealed that, although it is locally common, the total population is small and it is likely to have declined owing to degradation of its specialised habitat by agricultural and urban expansion and fuelwood collection.
The population was estimated to number at least 5,200 mature individuals by Roxburgh (2007) after a comprehensive survey of historical sites. This is equivalent to at least 7,800 individuals in total.
Roxburgh (2007) estimated that the range (no. of quarter degree grid squares occupied) appears to have declined by 25-50% since historical times, mostly in the last 20 years, owing to the loss and degradation of habitat. This process is on-going, and the population is likely to have declined at a similar rate over the same period.
Lybius chaplini is endemic to Zambia, where it is distributed from the upper Kafue River to Kabanga in the Kalomo District (Winterbottom 1952, Benson and Irwin 1965, Colebrook-Robjent and Stjernstedt 1976). Its range size has been estimated as 76,000 km2, but only 9% of this is thought to be occupied and there are estimated to be only 5,200 individuals (Roxburgh 2007). There are eight known subpopulations located in NRCA and neighbouring farms, Choma West-Sibanyati, Kalomo, Landless Corner and Chisamba, north Kafue Flats, south-east Kafue Flats (including Mazabuka and Monze), south-west Kafue Flats, and possibly Lukanga Swamps (the presence of birds in the last area is yet to be confirmed) (Roxburgh 2007). Within this small range, it is locally common where there is suitable habitat (Colebrook-Robjent and Stjernstedt 1976, R. J. Dowsett in litt. 1982, 1999).
It is almost invariably found in very open woodland with high densities of fig trees Ficus sycomorus, which provide a year-round supply of food as well as suitable nesting sites. Groups of two to six or more habitually roost and forage together, feeding mainly on figs but also on other fruits and arthropods (R. J. Dowsett in litt. 1982, 1999). Pairs nest almost exclusively, in holes in dead branches of Ficus sycomorus (Roxburgh 2007), and the species is a cooperative breeder, with groups consisting of two-five adults and up to four immatures from the current season (Roxburgh 2009). They breed in the dry season before the onset of summer rains in November (Roxburgh 2009). Territories cover up to 100 ha (Roxburgh 2009).
Although fig trees are sometimes left when areas of woodland are cleared for cultivation, and L. chaplini appears to be able to survive in partially degraded habitats, woodland clearance for agriculture (especially maize, wheat and sugar cane), and for housing, is decreasing the area of suitable habitat and is likely to lead to the loss of two subpopulations in the next few years (R. J. Dowsett in litt. 1982, 1999, Roxburgh 2006, Roxburgh 2007). Dead branches are removed from standing fig trees for fuelwood, and this is correlated with a decrease in barbet density (R. J. Dowsett in litt. 1982, 1999, Roxburgh 2006, 2009). There may be a minimum threshold density of fig trees necessary to support these barbets with a year-round supply of figs. Lesser Honeyguides Indicator minor parasitise up to 50 % of nests, while the smaller but more adaptable Black-collared Barbet L. torquatus competes for nesting holes (Roxburgh 2009).
Conservation Actions Underway
Small numbers of this species are found in Kafue National Park (R. J. Dowsett in litt. 1982, 1999), and the Nkanga River Conservation Area IBA holds c.50 birds (Roxburgh 2009). A survey of historical locations has been completed (Roxburgh 2007). Surveys across Zambia have been carried out since 2014 by BirdWatch Zambia with support from Isdell foundation (Phiri 2014)
Text account compilers
Mahood, S., O'Brien, A., Robertson, P., Symes, A. & Westrip, J.
Dowsett, R., Frost, P., Leonard, P. & Roxburgh, L.
BirdLife International (2019) Species factsheet: Lybius chaplini. Downloaded from http://www.birdlife.org on 19/09/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/09/2019.