2.2 Study area
This study was conducted in the Dashanbao National Nature Reserve (Dashanbao, N27°18′38 ″ -27°29′15″, E103°14′55″-103°23′49″), SW China. Covering an area of 19,200 ha, Dashanbao was first established in 1993 and upgraded to national level in 2003 for protecting the global threatened Black-necked Crane and plateau wetlands on which waterfowl depend. Dashanbao was famous not only for its role as an important wintering ground for black-necked cranes, but also a vital staging and stopover site for the eastern population of the bird (Kong et al., 2014b). Each year there are nearly 1,500 individuals wintering at Dashanbao, constituting 40% of their eastern population and ~14% of the world population (Yang and Zhang, 2014). In 2004, Dashanbao was designated as a Ramsar wetland of international importance as the contribution in black-necked crane conservation. There are four roosting sites, named Dahaizi, Xiaohaiba, Changhuikou and Yinjiabeihaizi, located along the lakeside of Dashanbao reserve (Fig. 1). Dahaizi is the most famous site as supporting the largest number of 600-900 black-necked cranes each year (Kong et al., 2014b).
Gathering of the gorgeous cranes attracted massive influx of people there for bird-watching, photography and also landscape viewing. The local authority started nature-based tourism program in 2009. According to reports of Dashanbao administration bureau, over 10,000 tourists, more than 10 times before tourism was implemented, went to Dashanbao at the end of 2009, with a yearly increasing rate of >30%. Over 60,000 people were recorded in 2013-2014 (Yang and Liu, 2014), sixty times of increase in abundance after entrance permit to the public. Sharp increase in tourism caused great threats to the black-necked crane population and other wildlife there. As the Dashanbao ecotourism overall plan indicated four discrete areas (named Dahaizi lake area, Tiaodunhe lake area, Jigong mountain and valley area, and Yanmaidi lake area) opened to the public, where three of the four black-necked roosting sites were located in two of these areas (Figure 1). People went to Dashanbao visit Dahaizi Lake area (for crane observation and photograph) and Jigong mountain and valley area the most (Yang and Liu, 2014), occasionally they drove around the Tiaodun Lake, but seldom to Yanmaidi lake where cranes were occasionally present. Thus, cranes were distributed in the Dahaizi and Jigong area and along the roadside to these areas facing high levels of disturbance, and cranes in Tiaodunhe area are facing intermediate disturbance while cranes in the other areas encountered the lowest disturbance from local native people (Figure 1).
INSERT FIGURE 1 HERE