Supreme the oranges by cutting away the peel, then slicing along the sides of the membranes to remove the segments. Set aside the segments. Squeeze the empty membranes over a bowl to get out the remaining juice.
Shred the duck meat and place in the bowl containing the orange juice.
In a large skillet, heat a little olive oil over medium heat. Sauté the onion and garlic for 2 to 3 minutes, stirring constantly.
Add the shredded duck, orange juice and cinnamon. Cook for 5 to 7 minutes, stirring occasionally, until the liquid has evaporated and the duck is lightly toasted.
In another large skillet over medium heat, warm the tortillas about 30 seconds on each side.
Place the duck mixture, orange segments and cilantro in the tortillas. Serve with lime wedges.