# Networked Unmanned Aerial Vehicles for Surveillance and Monitoring: A Survey
## 4 Wildlife Monitoring UAVs  
Wildlife living conditions are deteriorating as a result of global climate change. To protect endangered wildlife and to design better wildlife management strategies, policymakers and ecologists rely on wildlife monitoring to acquire the necessary information on the health of wildlife populations and ecosystems [60]. The inability to reach wildlife habitats due to complex terrains is a major problem in wildlife monitoring. With superior manoeuvrability and flexible operations, UAVs can help solve these problems. In particular, UAV technology has opened up new ways to monitor wild animals, such as counting animal groups and determining gender using visible or thermal imaging [61]. With their ability to accurately estimate wild animal numbers and distribution at previously inaccessible areas and spatial resolutions, UAVs have the potential to revolutionize ecological research paradigms. In addition, UAV monitoring can provide important ecological insights by providing a wide aerial viewpoint that allows for a clear view of the animals' interactions with their surroundings. An increasing number of countries and organizations have adopted UAVs to conduct observations of wildlife in hard-to-reach places. From monitoring sandhill cranes in Colorado and counting waterbirds in Florida to investigating orangutan dens in Indonesia and seals in Arctic waters, UAVs fly at safe distances, protecting endangered wildlife and enabling environmentalists to work more safely, accurately, and economically. A summary of the existing publications on UAVs for wildlife monitoring can be seen in Table 1. The examples of wildlife-monitoring UAVs for protecting whales, koalas and elephants are as shown in Figure 6. We now introduce some of the representative works on UAVs for wildlife monitoring. Figure 6: Examples of wildlife-monitoring UAVs for protecting whales, koalas and elephants. For marine biology, the 'SnotBot' project [62] uses a modified DJI Inspire 2 UAV to conduct whale research. In particular, SnotBot collects blowing samples of whales as they surface and exhale. The collected blow samples contain the whale's DNA, microbial communities, tissue particles, stress and pregnancy hormones, and viruses, all of which are important indicators of the whale's health. In addition to being a non-lethal and non-invasive approach to ocean research, protective UAVs such as SnotBot are also democratizing opportunities for ocean research. While research has long been confined to a privileged few because the chartering of expensive marine ships and equipment requires serious financial support. However, now, UAVs in oceanography are making data collection affordable, replicable, and scalable for researchers everywhere. In 2019-2020, an unprecedented bushfire swept more than 12.6 million hectares of land across Australia and caused the death of more than 61,000 koalas (one of the iconic marsupials in Australia). Sadly, even before the bushfire crisis, koalas were considered vulnerable to extinction due to threats posed by hunting, land development, food degradation, drought, and disease. After the bushfires, finding surviving koalas in burned and unburned areas became an urgent problem. To solve this problem, Australian ecologists presented an infield protocol for wild koala surveillance UAVs, which provides real-time validation of high-resolution thermal signatures of koalas [76]. The authors also provided detectability considerations relative to wildlife-UAV interactions, temperature, survey time, and detection of non-target species, which can be used to further inform UAV survey protocols. Once a koala is located, a hyperzoom vision camera on the same UAV helps first responders determine whether they need medical help. Mapping wildlife using thermal UAVs is much cheaper and more efficient than using traditional survey methods because koalas have strong camouflage abilities and are hard to be spotted. Moreover, thermal imaging UAVs have also become a powerful tool in the areas of fire protection. From