[Mystery bird] Irania, also known as the White-throated Robin, Irania gutturalis, photographed at Nyumba ya Mungu Reservoir, Tanzania, Africa. [I will identify this bird for you in 48 hours]
Nikon D300, 600 mm VR lens. ISO 500 1/400 sec, f/6.3.
Please name at least one field mark that supports your identification.