So you are photographing birds. You are using your long glass, a 500mm lens mounted up and you are getting good sized images of the birds from about 12-15 feet away. How close does a coyote or a javelina show up in the view finder? TOO CLOSE!!!
These are 2 almost full frame images taken of both critters in Big Bend National Park. Always keep a short lens around
Be prepared for big things getting too close on your journey†††nada te turbe†††jim