Table 4 Selected landscape metrics of the M. squamatus wintering distribution in central and east China for 2014, 2015, 2016 and maximum distribution

No. of habitat

6226

6017

8660

12,500

Total area (km²)

218,839

165,983

259,863

517,386

Proportion (%)

5.01

3.80

5.95

11.84

Mean patch area (km²)

35.15

27.59

30.01

41.39

Largest patch area (km²)

20,287

14,795

41,894

80,880

Total core area (km²)

106,281

72,600

118,269

271,833

Core area proportion (%)

2.43

1.66

2.71

6.00

Mean core area (km²)

17.07

12.07

13.66

21.75

Max patch core area (km²)

13,903

11,392

31,010

61,170

Habitat cohesion index

9.83

9.82

9.89

9.92