Abstract:

Scale is a critical factor in species ecology, and multi-scale approaches can potentially better depict the relationship of the bird species and environment. Yellow River Delta Nature Reserve(YRDNR)is a important site for red-crowned crane during migration and wintering. By using habitat suitability models and varying the spatial scale from 10 to 1,500 ha, we developed univariate models to analyze contributions of each environmental factor at each spatial scale to red-crowned crane occurrence. Moreover, multivariate models at single and multi-scales were built to seek optimum habitat suitability model. The results showed that univariate models varied among the environmental factors and with spatial scales. Within multivariate models, the single-scale model at the 50 ha scale performed best. The multi-scale model, in which each environmental variable was entered at the scale at which it had performed best in the univariate model, was superior to all single-scale models. Moreover, the results showed that the suitable habitat area of red-crowned crane in the southern part of YRDNR is far more than in the north. For effective protection of red-crowned crane habitat in YRDNR, we suggest that monitoring, assessment, reassignment of wetland should be strengthened and human disturbance should be under surveillance.

Key words: red-crowned crane, scale, habitat suitability model, Yellow River Delta Nature Reserve