The goal of researching the development of sustainable tourism in protected areas, which are trying to be tourist destinations, is to gain ecological, socio-cultural, and economic benefits for residents, visitors, and stakeholders. This means that residents, visitors, managers, and state services should be directly involved in the planning and implementation as important bearers of tourism development planning. Tourist activities in protected areas should be directed towards the improvement of ecological principles, socio-cultural attitudes, the realization of economic profit, and the strengthening of institutions. There is no doubt that protected areas contribute to the preservation of biological diversity and ecosystems, as well as the habitats of various plant and animal species. In this way, they enable scientific research, and different types of education with the aim of adequate use of these areas for the purpose of sustainable tourism ^[1][2][1,2]. In these areas, tourism significantly contributes to the preservation of natural and anthropogenic resources, the ethnic heritage of the local population, and the improvement of their economic situation ^[3][4][5][3,4,5]. Protected areas in the world contain rare ecosystems, habitats, and species that attract tourists ^[6][7][8][6,7,8]. The possibility of observing the natural environment, flora and fauna is a special attraction [9]. Numerous tourism development strategies in Serbia include exactly those destinations with sensitive ecosystems. One of the purposes of tourism development is the promotion of the ecological values of tourist destinations. It is also significant from the aspect of sustainable tourism ^[10][11][10,11].

There is an extremely rare ecosystem in the Special Nature Reserve “Meadows of Great Bustard” (MGB). This ecosystem consists of the plain, steppe, salt marsh, and marsh habitats. The symbol of this reserve is the endangered flock of Great Bustards (Otis tarda) in Serbia [12]. It is a globally vulnerable (VU) ^[13][14][13,14] and a highly endangered species in Serbia ^[12][15][12,15]. In the local community, there is not enough power to protect this area. Therefore, it is necessary to plan a more significant role that residents would get through personal control and sustainable development of tourism in MGB, with the possibility of creating tourism development strategies.

2. Satisfaction with Sustainable Tourism

Vital information on the importance of protected areas for tourism offers and sustainable development can be obtained through research on sustainable tourism in protected areas ^[16][17][23,24]. Numerous scientific studies examine the significance of the development of local communities and their connection with the ecology of protected areas, in order to preserve biodiversity ^[18][19][25,26]. Sustainable tourism generates the roles of all stakeholders in the creation of tourism development. Sustainability takes into account geographical features and different environmental and local conditions ^[20][27]. Therefore, the basis for sustainable tourism progress is a constant study of tourism and the identification of the roles of interested parties in planning and controlling tourism evolution ^[21][28]. During the development of tourism in preserved areas, numerous goals must be met ^[22][30]. In researching these areas, the most important goals are those related to the development of ecology, socio-cultural elements, economic growth, and the inclusion of institutions ^[23][24][31,32]. Sustainable tourism in protected areas is based on a system of plans, measures, and activities ^[25][33] which should be included in tourism development ^[26][27][34,35]. The objective of such a development is to satisfy tourists and the local population, gain income from tourism, and use it for the development of special forms of tourism on the territory of the protected areas ^[28][29][36,37]. The development of certain forms of tourism, such as ecotourism, nature conservation, hiking, excursion, educational, sports-recreational, rural tourism, and gastronomy, can significantly influence the promotion of protected areas as tourist destinations ^[27][30][31][35,38,39]. Providing income should be focused on improving the natural values of these sensitive destinations, which represents a significant pillar of sustainability. At the same time, the ecological aspect is the driving force behind other sustainable dimensions, such as economic, socio-cultural, and institutional. In the existing literature, in addition to ecotourism, nature-based tourism forms are mentioned as crucial forces of sustainability in protected areas. Some forms of tourism can contribute to the strengthening of various factors that affect the growth of tourism in protected areas ^[32][40]. A destination where ecological values are violated is not attractive to visitors ^{[33][34][35][36]}[41,42,43,44]. In addition to elementary attractive tourist factors, the evolution of tourism in protected areas can be influenced by other factors, such as the protection of the area, the intensity of its use, and its carrying capacity ^[37][45]. The role of the local community in tourism development, zoning, socio-cultural influences, the contribution of tourism to the local economy, development control, waste management, and others are also essential ^{[26][28][33][38][39][40][41][42]}[34,36,41,46,47,48,49,50]. Besides, the level of degradation of the specific area caused by mass tourism ^[43][51], and the number of inhabitants around the protected area and protection zone are also highlighted. It is known that tourism is an extremely vulnerable activity, so there are many factors that influence its development. First of all, air and water pollution, protection costs, the impact of human activities, social impacts, mass travel, and the creation of new and different types of tourism ^[33][44][45][41,52,53]. That is why there are many studies on these effects. Research on residents’ attitudes and perceptions of tourism development may provide valuable information for decision-makers ^[46][54], and it is crucial for successful and sustainable tourism development. Several studies revealed that residents’ support and their perceived benefits are preconditions for tourism sustainability ^{[47][48][49][50]}[55,56,57,58]. The involvement of host communities plays an important role in determining the success of sustainable tourism ^[51][52][59,60]. However, many local residents may be slow to diffuse their knowledge of sustainable tourism development compared with local governments and local opinion leaders ^[53][61]. Residents’ perception of sustainable tourism development potential in their particular place is crucial for their attitude and behavior ^[54][62]. Jurowski and Gursoy ^[55][63] found that residents who receive more benefits favor the development of sustainable tourism at a higher level than those who receive no or few profits. Wang ^[56][64] revealed that factors such as: witnessing negative environmental events, formal environmental education, the media, as well as individual outdoor experiences have positive effects on residents’ attitudes toward sustainable tourism. Zhu et al. ^[54][62] suggest that increasing local residents’ benefits, decreasing their costs from tourism, raising their positive perceptions and confidence in tourism, and inspiring their attachment to the community would help to enhance their support for tourism development. Moreover, they might then be more enthusiastic about local policies and affairs of tourism development, and maintaining the sustainability of local resources. If resident perceptions and preferences do not support tourism development policies and programs, programs are likely to fail or be ineffective in implementation, ultimately failing to achieve sustainability ^[57][65]. Many authors apply the PoS model for their research. This was also done by Huayhuaca et al. ^[58][66], whose research objective was to study the impact of sustainable tourism on the local population in Frankenwald Nature Park in central Germany. As part of that research, the respondents stated four dimensions of sustainability: ecological, economic, socio-cultural, and institutional. In addition, the impact of sustainability dimensions on residents’ satisfaction was studied. The research results have singled out ecological and socio-cultural sustainability. Furthermore, sustainable tourism has had an impact on residents’ satisfaction with sustainable tourism, which stands out as a significant result of the research. Similar research was done by Cottrell et al. ^[59][67], surveying visitors in two protected areas in Germany. The methodology of this research was mainly based on the PoS model on the examination of ecological, economic, socio-cultural, and institutional sustainability to the satisfaction of the local population. Research results indicated the importance of ecological and socio-cultural sustainability to the respondents. They identified four dimensions of sustainability as significant factors for tourism development. The research of Asmelash and Kumar ^[60][68] is based on the study of the functions that protected areas could have in sustainable tourism development. They conducted research by measuring four dimensions of sustainability in the regional state of Tigray, which is one of the nine regional states of Ethiopia. In the research results, the economic, socio-cultural, and institutional sustainability indicators stand out as significant, while the most important dimension is ecological. This can be related to the state of ecological factors within the observed protected area. The impact of sustainable tourism on residents’ satisfaction was investigated by Trišić et al. ^[61][69], through the individual impacts of each of the four dimensions of sustainability on the sustainable development of tourism within two protected areas in Serbia and Croatia. The PoS model was also used during this research. The research results singled out the ecological and socio-cultural dimensions of sustainability as the most significant for sustainable tourism. The importance of including residents in the processes of management, organization, and control systems is part of the obtained results. In addition, the conclusions of this research confirmed that the importance of local culture, tradition, customs, cultural-historical heritage and crafts is important, in addition to natural values. The primary forms of tourism are nature-based tourism and ecotourism. A very important part of tourism evolution planning, especially in protected areas, is the carrying capacity of the spatial location. Apart from positive effects, tourism can also have a very negative impact on the overall development of a location, which occurs in the case of its massive and uncontrolled development. This is exactly the kind of tourism growth that must not take place in very sensitive and conserved areas. It is extremely important that those who manage protected assets take into account all levels of assessment of carrying capacities: ecological, psychological, socio-cultural, and economic capacities. When planning and implementing tourism, one must understand and accept the limitations of the carrying capacity through these four levels, and in that way, direct the proper growth of tourism to the satisfaction of the local population and visitors. It is a very important compromise between the desire for a large number of tourists and the possibility of accepting them in protected areas such as the MGB. According to the sustainability implementation model proposed by Haid et al. ^[62][70], communication between destination stakeholders is crucial for the successful implementation of sustainability initiatives. It has to be taken into account that promoting sustainability, carrying capacity, and advocating for sustainability to local businesses are key factors. Destination management organizations play a vital role in communicating sustainable efforts, advocacy for sustainability internally and externally, and the importance of tourism initiatives to the locals. The authors also stressed that involving various stakeholders and fostering cooperation through communication are essential drivers for the process, as communication becomes a primary driving force by replacing discretion. Communication is a key element not only for external communication of the national parks and protected areas with residents and other stakeholders. Smith et al.’s ^[63][71] study set in a South African context revealed the importance of effective communication for park managers during the COVID-19 period, leading to positive outcomes, such as increased use of online communication technology, time and cost savings, and the need for empowering staff through ongoing open communication. Ramkissoon ^[64][72] concludes that a harmonious relationship among residents, places, government, businesses, and tourists promotes social, environmental, and economic sustainability in sustainable tourism development. Communication with residents is key to understanding their perceived social impacts of tourism and developing appropriate management strategies to support tourism development. As this protected area has a very rare ecosystem and endangered representatives of flora and fauna, special attention must be paid to the carrying capacity when planning tourism. The assessment of the carrying capacity for the MGB should be the result of the impact of tourism on the environment and should represent an important component of planning the development of tourism activities in this protected area. It can be one of the mechanisms for setting sustainable tourism standards. So far, several attempts have been made in order to reliably define the bearing capacity that would refer to the MGB. This especially applies to all types of tourist activities, including the development of tourism of special interests, among which are scientific research and ecotourism. Bearing in mind that the majority of negative environmental and other problems are caused by a large concentration of visitors, tourist capacities and contents, many authors deal with defining the carrying capacity and the necessity of determining the maximum number of tourists who can stay in a certain spatial area at the same time. Data research concludes that the carrying capacity represents the maximum number of people that can be located in a certain locality, without irreversible changes and degradation of the physical environment, and without significantly compromising the quality of the recreational experience ^[65][73]. Many studies have been carried out around the world, and especially in the USA, with the aim of specifying the procedures for calculating the carrying capacity and creating specific formulas, which would be valid for a certain type of tourist destination, such as protected areas. Despite this, there is still no reliable and scientifically proven method for calculating bearing capacity accepted throughout the world. Most authors or organizations studying this problem use different standards obtained from their own research and experience. Each perception during the research is very different, so this also affects the specificity of the applied standards. Using different parameters, a carrying capacity of 40 people per kilometer of the educational trail can be recommended in this nature reserve. With such a small number of visitors, the natural activities of the Great Bustard will not be disturbed.