[Mystery bird]Gray Wren-warbler (perched), also known as a Zambia Wren-warbler or Western Wren-warbler, Calamonastes simplex, and a Lesser Striped Swallow (flying), also known as a Striped Swallow, Hirundo abyssinica, photographed near the Pangani River Camp, Tanzania, Africa. [I will identify this bird for you in 48 hours]
Nikon D300s, 600 mm VR lens. ISO 640, 1/640 sec, f/5, Exposure Compensation +3.7.
Please name at least one field mark that supports your identification.
You’ve seen one of these two African mystery bird species before, and it closely resembles a North American species as well, so you should be able to ID that bird to genus, at least (I admit that the other one is going to be challenging)