https://phaidra.vetmeduni.ac.at/o:5074 Use of thermal imaging to collect fresh faeces for non-invasive evaluation of stress levels in the European hare (Lepus europaeus) Skoták, Vlastimil Vlastimil Skoták Cukor, Jan Jan Cukor Sedláček, Marek Marek Sedláček Ševčík, Richard Richard Ševčík Linda, Rostislav Rostislav Linda Brynychová, Kateřina Kateřina Brynychová Kostka, Matěj Matěj Kostka Macho-Maschler, Sabine Sabine Macho-Maschler 0009-0001-2428-6141 University of Veterinary Medicine Vienna Hušek, Jan Jan Hušek Palme, Rupert Rupert Palme 0000-0001-9466-3662 University of Veterinary Medicine Vienna Frontiers Media SA journal article open access eng Assessing long-term stress in wild animal populations is extremely complicated and, in some species, practically impossible due to the complexity of sampling. Here, we tested and verified a unique non-invasive method for collecting fresh faecal samples located using thermal imaging cameras from a model species, the European hare. Subsequent analysis of faecal glucocorticoid metabolites (fGCMs) allows for the determination of stress levels without capture of individuals in hare populations. fGCM values ranged from 1.8 to 65.8 ng/g. Whilst the average value across locations in winter was 15.6 ng/g ± 9.9 SD, values in spring (April/March) were significantly higher (18.2 ng/g ± 11.2 SD; p < 0.05). These higher values coincided with the peak in European hare reproduction in spring. Significantly higher values were also confirmed in urban environments, indicating increased stress levels compared to natural environments, despite hares appearing to have adapted to the urban landscape. Higher values were also found in structurally poorer landscapes than Austrian rich agroecosystems. Having proved the usefulness of thermal imaging cameras for collecting large numbers of fresh droppings for the non-invasive evaluation of stress in wild hare sub-populations, we suggest the method could be applied to other species where capture and handling exert stress, injury or mortality. Animal Welfare Biodiversity Conservation Cortisol Intrapopulation Stress Non-invasive Monitoring Wildlife Monitoring http://creativecommons.org/licenses/by/4.0/ https://phaidra.vetmeduni.ac.at/api/object/o:5074/download 10.3389/fvets.2025.1682443 https://phaidra.vetmeduni.ac.at/o:605 application/pdf Frontiers in Veterinary Science issn:2297-1769 VoR Frontiers in Veterinary Science 12 1.08 MB 2025