Epicurious.com and MarthaStewart.com recommend roasting a 5- to 6-pound duck at 425 degrees Fahrenheit in the oven for 2 1/4 to 2 1/2 hours. The duck should have an internal temperature of 165 F when done.
Because domesticated duck is all dark meat and fatter than chicken, cooks roast them longer to ensure the meat is cooked thoroughly and the fat is rendered. Wild duck is not as fat as domesticated duck.
MarthaStewart.com and TheHungryMouse.com recommend scoring and pricking the duck's skin prior to roasting to help render fat during roasting. TheHungryMouse.com, however, prefers slow roasting duck on 300 F for four hours and then 400 F for 10 minutes to finish.