Mystery Bird

As a child I roamed the fields well clear of noisy traffic. I was an egg collector but no longer I respect all life that does not threaten me. On our walks which have a natural silence with the puppy who has prodigious levels of energy we have come across a mystery. A bird that I cannot identify.

Clues
1. Rich chocolate brown back
2. Larger than a blackbird
3. We think possibly a bird of prey but.............
4. Territory near a marsh
5. Always seen on the ground before being disturbed
6. Flying pattern extremely dynamic.

It is not a jay, sparrow hawk, owl, fowl, ..............................................

To be continued..............

Answer A Woodcock.