When employed in large numbers over extended periods of time, trackers can gather large quantities of complex, rich biodiversity data that cannot be gathered in any other way. One significant result in the Congo was that data collected by trackers made it possible to alert health authorities to outbreaks of Ebola in wild animal populations, weeks before they posed a risk to humans. Trackers can also play a critical role in preventing the decimation of large mammal fauna due to poaching. Collectively, the seven case studies reviewed in this paper demonstrate the richness and complexity of scientific data contributed by community-based citizen science. Furthermore, trackers can also make novel contributions to science, demonstrated by scientific papers co-authored by trackers. This may have far-reaching implications for the development of an inclusive citizen science. Community-based tracking can significantly contribute to large-scale, long-term monitoring of biodiversity on a worldwide basis. However, community-based citizen science in developing countries will require international support to be sustainable.