x2 photos. Double click to enlarge.
Species Musca autumnalis. A sexually dimorphic species where the males have bright orange and black patterned abdomens and the females are light grey and black. These are obviously all males.
This species gets its common name from its habit of landing on the faces of cattle or horses where they feed on secretions of the facial orifices, around the eyes, mouth and nostrils. The adult flies will also feed on the hosts blood through wounds such as Horse-fly bites. The larvae develop in animal dung.
I came across these in a local horse pasture sunning on a fence post. There were several of them, all males, and they were quite approachable to photograph.