Abstract:[Objective] The sense of smell of most birds has been considered to be degraded, although some bird species have well-developed olfactory organs. While, a few studies reported whether odors can affect the feeding behavior of birds. Here, we aimed to test whether feeding behavior of Budgerigars (Melopsittacus undulates) can be affected by six odors, including feces of Ural Owl (Strix uralensis), feces of Golden Eagle (Aquila chrysaetos), feces of domestic dog and feces of domestic cat, as well as perfume and cigarettes. [Method] Before the experiment, one of those six odor sources was placed on the lower layer of the double-layer food box (custom-made, with 225 air vents between the layers), and seeds were placed on the upper layer. A Budgerigar (starvation treatment for 4 hours) was individually transferred to an observation cage. After a 5 minutes, a double-layer food box was placed in the observation cage, and then we observed the behaviors of the target Budgerigar for 15 minutes. In addition, an odorless control group was established at the same time. Each bird received all 7 types of odor experiments, while the order of treatments was random. During observation period, we recorded the distance between the Budgerigar and the food box, and counted the number of feeding times of Budgerigar. The cumulative link mixed model with logit-link function was used to analyze the feeding willingness (whether closed to the food box) (Fig. 1) and feeding level of Budgerigars (low level, the feeding frequency was 0; medium level, the feeding frequency was between 1﹣10; high level, the feeding frequency was > 10) under different odors. In the models, treatment and sex were treated as fixed terms and ID was a random term. If there was a significant effect of treatment, we further performed post hoc pairwise comparisons and used false discovery rate control to adjust P values. [Results] There were significant differences in the feeding intentions and feeding level of Budgerigars under different odor exposures. Except the feeding intention under the odor of perfume was significantly lower than that of the odorless control and the odor of Ural Owl feces, there was no difference in feeding intention between any other two treatments (Fig. 2). The feeding level of Budgerigars under the odor of Golden Eagle feces, cat feces, perfume, and cigarette was significantly lower than that of the odorless control, and the feeding level under the odor of perfume or cigarette was significantly lower than that of odor of Ural Owl feces (Fig. 3). In addition, there was no difference in feeding level between any other two treatments. [Conclusion] Our results showed that the Budgerigars performed different feeding behaviors under different odors. Here, we suggested that the Budgerigars might be able to assess the potential predation risks in the environment by odors and then adjust their feeding behaviors.