For most animals, adequate food and energy intake is essential for the maintenance of normal life activities. Food intake-which depends on the availability of different foods, feeding time and palatability-is closely related to environmental factors, and is a critical factor affecting energy balance in some birds. The present study was designed to examine the impacts of differing food intake on energy budget and behavior in winter Red-crowned cranes (Grus japonensis), and to check the feasibility of the feeding method in Qiqihar, Heilongjiang Province, China. Red-crowned cranes were housed individually in cages (6m×4m×4m) in their natural habitat in Zhalong Nature Reserve (46°52'-47°32'N, 123°47'-123°37'E) during December 2013. Twenty-three adults older than 5 years of age were divided into three groups and fed a diet of crucian carp (4♀, 4♂), corn (4♀, 4♂), or a combination of both (4♀, 3♂), respectively. During the feeding experiment, they were maintained in natural conditions, with a short photoperiod of near 8L:16D and an average temperature of -12.8℃. After a week, we compared changes in behavior, body mass, energy budget and fecal discharge frequency among different diet treatments in the winter birds. The birds were weighed (to 0.01kg) by the breeder (Method: (A+B)-A, where A is the breeder's weight) at the start of the experiment, and then at weekly intervals over the period of food availability acclimation. At the same time every day during the experiment period, we chose two birds from each group and recorded the total distribution time of the different behaviors. Energy and water intake was measured for every bird. The amount of supplied and residual food was weighed every day of the experiment, and the caloric content of food intake was determined using an oxygen bomb calorimeter. The fecal discharge frequency was calculated by counting fecal deposits five times every day; after which the deposit was removed to ensure accurate measurement. After acclimatization, we found that the body mass and behavior of G. japonensis changed significantly with different diets. The body mass of birds feeding on corn was significantly lower than others after the effects of initial body mass were eliminated (P < 0.05), while the duration of resting behavior increased significantly (P < 0.001). Energy budgets were also significantly different between the three experimental groups after the effects of initial body mass were eliminated, including significant differences in the intake of food, water and energy, the cooling energy of water discharged, and the fecal discharge frequency (P < 0.05). Further, the food intake, energy intake and cooling energy of water discharged by birds feeding on corn were significantly lower than that of birds in the other two treatments. Indeed, many aspects could have influenced the observed differences among treatments in the energy budget and behavior of winter G. japonensis. For example, perhaps the feeding time for crucian carp was limited by the low temperature and short light cycle of experimental conditions. Poor palatability of corn kernels could have led to a decrease in food demand and hence energy intake. Finally, birds feeding on a combination of fish and corn could have received more abundant nutrition from the hybrid diet. To summarize, to maximize energy intake and nutrition in the species, it is necessary to consider the daily light cycle and temperature of the environment. Further, the method of mixed feeding at Zhalong Nature Reserve provides a more balanced diet to Red-crowned Cranes over winter.