Habitat quality of overwintering red-crowned cranes based on ecological niche modeling

Abstract

Ecological niche modeling is particularly valuable for predicting the true and potential distribution of wild birds. The core zone of the Yancheng National Nature Reserve (YNNR) is the largest overwintering habitat of red-crowned cranes in the world. Based on a GF-2 image in 2015 and field data related to micro-habitats of cranes, five functional factors were selected and analyzed with maximum entropy (MaxEnt) and boosted regression tree (BRT) models. The prediction results of the MaxEnt and BRT algorithms reached outstanding levels. Landscape type was the most important environmental factor affecting the habitat quality of overwintering cranes, while distance to water sources was the least contributing factors in both models. The response curve of the BRT was more reasonable than the MaxEnt at explaining habitat selection and utilization by cranes. It revealed that superior habitats are principally distributed in Suaeda salsa in natural wetlands. This habitat currently faces serious fragmentation and islandization. This study evaluates the quality of overwintering habitat for red-crowned cranes based on ecological niche modeling. The results provide a scientific basis for the protection of the overwintering habitat of this species of crane, and it is critical for species protection and management planning of nature reserves.