If your looking for a ton of great waterfowl recipes go to the Delta Waterfowl site;
http://deltawaterfowl.org
My two favourites are:
Slow roasted duck which is incredible(website) and my personal recipe which is:
Take your duck or Spec and pluck the breasts. As long as it is not too piny, take the breast meat off with the skin. This is essential. If you are just breasting your birds without the skin your eliminating the fat in the skin when cooking which is crucial.
Soak the breasts in salt water for 2-3 hours to leech all the blood out. Then dry them off and singe them with a candle taking off all the excess hairs.
For a marinade you have plenty of options. I use:
Buttermilk
OJ and teriaki
red wine and cracked pepper
Marinade for 1 day
If the birds are really old, I will use an injector and inject the breasts to ensure the marinade can break down some of the tougher tissue inside the breast.
BBQ at a really high heat. sear them for 30 seconds a side then turn your heat right down and let them cook with the meat side down, fat side up. Expect some flaring when the fat starts to burn. Coat with added marinade as an option. When you start to see blood coming out of the breast with the fat your at rare. DO NOT OVER COOK. I usually take mine off as they are just cooking from rare to medium rare. Cover and let the juices come out. Collect juices for gravy.
When you slice cut them with a fillet knife. Really thin with the skin on. As long as they are medium rare, you will not believe how good they are.
Enjoy