Home Range and Habitat Use of Breeding Black-Necked Cranes.

Wei Liu,Chenhao Zhao,Yuyi Jin,Bin Wang,Jianghong Ran,Yongjie Wu,Xingcheng He

doi:10.3390/ani10111975

Abstract

Simple SummaryThe Black-necked Crane is the only crane that breeds on the Qinghai–Tibetan Plateau, and it is currently classified as a vulnerable species. Habitat destruction and loss are the main threats for the Black-necked Crane. However, the breeding needs of Black-necked Cranes with regard to their preferred habitat remain unknown. To find the driving factors of their habitat selection, we studied the utilization rate of three habitats within the home range of Black-necked Cranes during four consecutive breeding stages. Black-necked Cranes mainly utilize meadows in the whole breeding season, followed by marsh meadows and marshes. Compared with other stages, the utilization of marsh habitat slightly increased in the postfledging stage. Since this stage is a very vulnerable period for young cranes, we suggest that grazing needs to be managed during this stage, that is, from late May to early September.To effectively protect a species, understanding its habitat needs and threats across its life-history stages is necessary. The Black-necked Crane (Grus nigricollis) is an endangered wetland bird species of the Qinghai–Tibetan Plateau, which is an important grazing area in China. To overcome the conflict between increasing grazing activities and the protection of wild cranes, we investigated the variation of habitat utilization within the home range of cranes at different stages (preincubation, incubation, postfledging, and fully fledged stages). We manually tracked 13 pairs of cranes in the Zoige international wetland, used the fixed-kernel-polygon (FKP) method to determine home-range size, and used satellite images to identify different habitat types. The average home-range size was 143.38 ± 34.46 ha. Cranes were most often located in meadow habitats followed by marsh meadows and marshes. During the postfledging stage, home-range size was significantly decreased, with the proportion of marsh habitat slightly increased. Since this stage is crucial for young-crane survival, research on the importance of marshes and effective protection measures should be further strengthened.

Highlights

From 1940 until today, the global number of breeding birds in grasslands has significantly declined [1,2]
The study was undertaken in the Zoige wetland (32◦ 200 –34◦ 050 N, 101◦ 360 –103◦ 550 E), which is located in the northeastern portion of the Qinghai–Tibetan Plateau (Figure 1)
When comparing the proportions of meadow areas within the home range, there was significant difference in the proportion of the 95% FKP meadow area among the four breeding stages (GLMM: F3,63 = 3.225, p = 0.028)

Summary

Introduction

From 1940 until today, the global number of breeding birds in grasslands has significantly declined [1,2]. Many waterfowl species typically nest and hatch in marshes, but forage in meadows that are some distance apart The reason for this split of areas is the lower availability of food in marshes; these birds often forage in meadows that are farther away [9]. Understanding the composition and size of different habitats in the home range, and their changes during different breeding stages, can help to clarify the distribution pattern of birds and the habitat requirements of breeding areas [12]. This knowledge helps the government to overcome the conflict between animal protection and grazing activities. A win–win model can be achieved by adjusting grazing density and turn-out date [13]

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