Camelthorn trees Vachellia erioloba provide an important resource for breeding Southern Pied Babblers Turdoides bicolor in the southern Kalahari
In the southern Kalahari Desert, cooperatively breeding Southern Pied Babblers Turdoides bicolor frequently build their nests and forage in camelthorn trees Vachellia erioloba, a keystone species in the region. Using Ivlev’s electivity indices (Ei), we show that Southern Pied Babblers preferentially nest (Ei = 0.18) and forage (Ei = 0.24) in camelthorn trees. Southern Pied Babblers primarily forage on the ground, however they will make use of arboreal resource when these are available. We observed the birds spending the highest proportion of foraging time off the ground during October, when breeding is also most common, compared to all other months within the austral summer breeding season. They are most likely to be observed in camelthorn trees earlier compared to later in the breeding season.We demonstrate that Southern Pied Babblers have a strong relationship with camelthorn trees, in which they prefer to nest and forage. We highlight the importance of protecting camelthorn trees, a keystone species in the region, as part of the conservation and management of endemic Kalahari fauna such as the Southern Pied Babbler. In addition to contributing to the literature on keystone species, our observations raise interesting questions about the ways in which avian reproduction in the arid zone could be decoupled from rainfall via the phenology of deep-rooted tree species.