Background One of the most challenging tasks in wildlife conservation and management is clarifying which and how external and intrinsic factors influence wildlife demography and long-term viability. The wild population of the Crested Ibis ( Nipponia nippon ) has recovered to approximately 4400, and several reintroduction programs have been carried out in China, Japan and Korea. Population viability analysis on this endangered species has been limited to the wild population, showing that the long-term population growth is restricted by the carrying capacity and inbreeding. However, gaps in knowledge of the viability of the reintroduced population and its drivers in the release environment impede the identification of the most effective population-level priorities for aiding in species recovery. Methods The field monitoring data were collected from a reintroduced Crested Ibis population in Ningshan, China from 2007 to 2018. An individual-based VORTEX model (Version 10.3.5.0) was used to predict the future viability of the reintroduced population by incorporating adaptive patterns of ibis movement in relation to catastrophe frequency, mortality and sex ratio. Results The reintroduced population in Ningshan County is unlikely to go extinct in the next 50 years. The population size was estimated to be 367, and the population genetic diversity was estimated to be 0.97. Sensitivity analysis showed that population size and extinction probability were dependent on the carrying capacity and sex ratio. The carrying capacity is the main factor accounting for the population size and genetic diversity, while the sex ratio is the primary factor responsible for the population growth trend. Conclusions A viable population of the Crested Ibis can be established according to population viability analysis. Based on our results, conservation management should prioritize a balanced sex ratio, high-quality habitat and low mortality.

The use of camera traps is prevalent in the ecological study of giant pandas (Ailuropoda melanoleuca). The reliability of camera-trap surveying results greatly depends on sampling designs that significantly influence the detection probability of the target species. Few studies have tested the efficacy of sampling designs on camera-trap surveys for monitoring giant pandas in a heterogeneous landscape. In this study, we conducted camera trapping of giant pandas based on two different sampling schemes in Changqing National Nature Reserve of China, and evaluated their outcomes based on three aspects: occupancy analysis, photographic rate, and activity pattern. The results demonstrated that both climate heterogeneity and distance to the nearest road had a strong positive influence on site occupancy, and slope and forest cover had a significant negative impact on site occupancy. Significant differences in the direction or magnitude of variables' influences indicated that there were apparently spatial-temporal dynamics of giant panda distribution between two sampling schemes. The low detection probabilities indicated that both sampling schemes were not robust to accurately monitor giant pandas in the whole study area. We recommended that more suitable sampling designs with local covariates be developed for camera-trap surveys monitoring giant pandas to account for temporal variability and small-scale variation in heterogeneous landscapes.