The ease of use and availability of unmanned aircraft systems (UAS) recently pervaded a wide range of topics and applications. In nature conservation and for the management of protected areas (PAs), UAS are still not an established approach compared to other methods such as satellite-based remote sensing, although several research articles have already discussed their use. In this context, UAS are even denoted as ‘conservation drones’, suggesting that their use is beneficial in terms of accomplishing various tasks such as land-cover mapping, vegetation monitoring, biomass estimation, and animal detection. However, although disturbance of wildlife or other issues caused by UAS are debated and guidelines for the use of UAS in wildlife studies suggest precautionary measures, the implications of the use of UAS in PAs has not been analyzed in detail yet. Therefore, by reviewing research articles, the present paper aims to show whether the use of UAS in PAs is relevant or irrelevant for the PA management in terms of biodiversity conservation, considers a controversial debate of the potential threats, and investigates whether the type of PA concerned matters in this context. We showed that a majority (73%) of selected articles (89) report the use of UAS in PAs as relevant for the PA management in terms of biodiversity. However, most of these studies did not consider impacts of UAS on wildlife or the environment. The possibility of disturbances was discussed in 15 (approx. 17%) of the reviewed works, of which most concluded that the effects were negligible or non-existent. Only in three articles (approx. 3%) an impact has been demonstrated. While most research studies discussing UAS in PAs do not report nor mention any impacts, UAS are banned in many PAs. Therefore, the use of UAS in PAs as ‘conservation drones’ and the related pros and cons need to be carefully considered by the PA managers and stakeholders concerned. Keywords: Protected area, Unmanned aircraft system, Disturbance effects, IUCN management category Schlagwörter: Schutzgebiet, unbemanntes Flugzeugsystem, Störeffekte, IUCN-Managementkategorie
