These Herons or Cranes were circling our neighborhood most of the afternoon. Not sure what was going on but they looked like they were migrating. I was sure these were Great Blue Herons when I took the photo. Since then, I've gotten closer shots and they look more like Sand Hill Cranes.
With FlightAware software on my iPhone, I figure that the aircraft was Aeromexico Aerovias Flight AMX6 From Paris to Mexico City... just under a 12-hour direct flight. They say it's a 767-200 which has a wing span of 156'. The Blue Heron or Sand Hill Crane span is about 6'. Using the lens focal length (250mm), I estimate that the 767 altitude is about 45,000' and the birds are at 3,000'.