Crested Ibis Nipponia nippon is one of the most endangered avian species in the world, with the only wild population distributed in Yangxian County of Shaanxi Province, China. Since 2004, reintroductions have been conducted in Shaanxi, Henan and Zhejiang Province. To further expand the range, 20 individuals were introduced to Beidaihe, Hebei Province in 2018 to establish the northernmost acclimatizing population. To reveal the adaptability of Crested Ibis to the local environment, the diurnal time budget and behavior rhythm of the acclimatizing population were analyzed in Beidaihe during the non-breeding period from July 2019 to January 2020. The results showed that the resting (41.8%), foraging (39.7%) and preening (13.3%) were the main activities. In terms of behavioral rhythm, there were three foraging peaks, two resting peaks, and two preening peaks. Adults and juveniles had similar time budget, but adult birds had a significantly higher proportion of vigilance and social behaviors. Compared with wild populations, the birds in Beidaihe spent significantly less time on foraging, while wild individuals had to spend more time on searching for food and consuming considerable energy in flying and other activities. The Crested Ibis spent more time in resting and preening while less time in foraging behavior in winter than those in summer and autumn. This would reduce energy consumption in low temperature and windy weather so as to adapt to the local climate conditions. In order to improve the adaptability of the Crested Ibis to various climate and environment, and prepare for the implementation of the reintroduction in the future, we suggest 1) to add some push-flow pumps to the simulated foraging wetland to prevent freezing of the water surface and increase the input of food such as loach, so as to ensure that the Crested Ibis has adequate feeding grounds in winter. 2) to carry out the environmental enrichment inside the cage, such as increasing evergreen and broad-leaved trees in the cage, installing windproof plates on part of the side nets, and setting up umbrella sheds against wind and cold weather to provide more choices for the Crested Ibis in cold weather; 3) to carry out more detailed observation on the behaviors related to bare parts protection to reflect the adaptation of the Crested Ibis to cold weather, and to conduct dropping sampling to reveal physiological adaptation; 4) to conduct pre-investigation on the distribution and status of suitable foraging habitat for the Crested Ibis nearby Beidaihe in winter, so as to make preparation the future release.