Obviously not a bird,depending on your relative motion to you, but when you look at it from a relative motion angle (i.e is it heading towards you or at a 90 degree angle or away) it would fit for a large bird carried by updrafts with the birds head on the right and the bird traveling to the right, not forward. An interesting example of how relative angles of view in a long distance picture can be one thing or another. If it was going towards the camera, it is a match for the Viggen.