Is it possible to get rabies from a duck?

Extremely unlikely. Rabies here is carried by raccoons, skunks, foxes, coyotes, and bats, which all can transmit rabies to cats, dogs, and livestock. A mammal can become infected with rabies. The virus is in saliva. In order to get rabies from a duck, the duck would have to be bitten by a rabid mammal. Then, the human would have to touch the wound and transfer some residual saliva into his own eyes, nose, or mouth.
No. Only mammals can be infected with rabies and potentially transmit the disease. Species that pose no risk of a rabies direct transmission include avians ( e.g., chickens, ducks, geese, hawks, eagles, owls, and even vultures), reptiles (lizards, turtles, etc.), and amphibians (e.g., frogs). http://epi.publichealth.nc.gov/cd/lhds/manuals/rabies/docs/other_animals.pdf.
Rabies in mammals. Rabies is not found in birds. The disease only occurs in mammals. Therefore, one can only get rabies from the bite (or scratch) of a mammal. About 1 in 1000 human rabies cases is from an animal scratch. If concerned about a real 'rabies exposure', wash out the wound thoroughly and see a doctor.