Do you have "casts shadows" checked in the bird's "properties" screen?

at the very bottom of the frame , and just in front of the bird, it looks like a shadow , could that be the bird ?  make sure the bird is set to cast shadows, and then just work from your light positions, you can actually use the shadow camera of the light to see where shadows will fall .

I think the bird is casting a shadow, but not where it's obvious or where you want it.  Check the position of the lights.

You should really use shadows on one light and use the other for fill or ambient lighting without shadows.  This is an outdoor scene; one major light is sufficient for casting shadows.

Also, if you're using Depth Mapped shadows, don't.   

Many Many Thanks to all. Now the shadow I am getting.

This topic made me think of a great Abe Lincoln quote, where he dismissed one of Stephen Douglas' arguments as being “as thin as the homeopathic soup that was made by boiling the shadow of a pigeon that had starved to death.”