Mandingoa nitidula
This secretive twinspot is found in eastern South Africa where it spends its time in moist forests, as well as woodland and coastal scrub in winter. Its insect like call and green upperparts (& in the case of the male, its red face) separate it from other similar species.
I first set eyes on this species while birding in Magoebaskloof with David Letsoala. We located two juveniles that only gave us a few seconds and a record shot before heading off. I have seen them on a number of occasions since then, including such places as Umdoni Park, Dlinza Forest and Amatikulu Nature Reserve. The Twinspot Hide at Kurisa Moya is undoubtedly the best location I have found to photograph them.