The potential role of wild mammals in avian influenza A virus (IAV) transmission cycles has received some attention in recent years and cases where birds have transmitted IAV to mammals have been documented. However, the contrasting cycle, wherein a mammal could transmit an avian-origin IAV to birds, has been largely overlooked. We experimentally tested the abilities of two mammalian species to transmit avian-origin IAV to mallards (Anas platyrhynchos) in simulated natural environments. Results suggested that striped skunks (Mephitis mephitis) can successfully transmit avian-origin IAV to mallards through indirect contact with shared resources, as transmission was noted in 1 of 4 of the mallards tested. Cottontail rabbits (Sylvilagus sp.) exhibited a similar pattern, as one of five cottontail rabbits successfully transmitted IAV to a mallard, likely through environmental contamination. These results suggest that certain mammal species should be taken into consideration in biosecurity plans.