The large area of the Chornobyl Radiation and Ecological Biosphere Reserve and the inaccessibility of some areas to the reserve's staff due to radioactive contamination make geospatial data collection methods a good alternative to traditional field sampling. The aim of the study is to assess the effectiveness and limits of applying contemporary tools of data collection and biodiversity monitoring in the Chornobyl Reserve. We used hierarchical cluster analysis to compare how well different ways of collecting data worked by finding the distances between groups of species in the following samples: the Fauna questionnaire, the iNaturalist platform, monitoring of large mammals as part of the Polissia without Borders project, and low-resource mammal surveys using camera traps. Incorporating GIS data collection techniques into field studies or inventories in a reserve is undeniably a powerful additional source of biodiversity information. The iNaturalist platform provides reliable data on species richness as well as seasonal and topographic distribution, despite its limitations in terms of the relative abundance and structure of species communities. The data obtained with the help of the Fauna questionnaire adequately describes the situation with the relative abundance and spatial distribution of large and medium-sized mammals, approaching such an accurate method as photographic monitoring using photo traps. Increasing the quantity and quality of results is possible by expanding the competence of staff in using the questionnaire and training aimed at identifying species by indirect signs such as traces, burrows, gnawing marks, etc. Geostatistical tools are valuable for the efficient use of technology and resources for inventory identification and generation, uniformity in biodiversity data collection, and effective data dissemination.