Birds play a key role in seed dispersal of plants. To investigate influences of tourism activities on bird-mediated seed dispersal, we conducted a comparison study by selecting Phellodendron amurense Rupr. individuals for observation at a recreation site and non-recreation site at the Khanka Lake Nature Reserve. The results showed that bird-feeding behaviors were significantly altered at the recreation site during rush hours with intensive visitation. Bird species richness, feeding frequency, feeding time, and predation numbers all markedly decreased. It was found that recreational disturbances were the fundamental factors leading to the changes in bird feeding behaviors. Changes in feeding behaviors of birds reduced opportunities for seed dispersal, further resulting in the reduction of recruits and shorter distances of dispersal. In addition, seedlings were mostly established inside the landscape at the recreation site, which was linked to changes in the paths birds flew caused by recreational disturbances. The results suggested that recreational activities could cause ripple effects on plants through disturbing animal-plant relationships.