I don't know if you're still looking for identification opinions for these starlings, but they look like Red-winged Starlings (Onychognathus morio) to me. There are 10 species in the genus Onychognathus and they all have a prominent wing patch (mostly red or reddish in color). About half of them don't occur in Ethiopia and several of them have long tails, which rules them out as being this species. That leaves us with Red-winged Starling and White-billed Starling (Onychognathus albirostris). Although the bases of the bills look light in color, I don't think that these are the solidly white bills of a White-billed Starling, so my opinion is that these are Red-winged Starlings. I believe that all of the Onychognathus species are sexually dimorphic with the males having dark heads and the females have gray or lighter colored heads. My guess is the bird on the far left and maybe the one in the tree are females and the other two are males. I hope this helps.
