Long-term variation in frequency of non-lethal shell injuries in a population of eastern Hermann’s tortoise, Testudo hermanni boettgeri

Variation in the frequency of non-lethal shell injuries was analyzed in an open population of the eastern Hermann’s tortoise ( Testudo hermanni boettgeri ) monitored in a complex habitat system between 2010 and 2024. Tortoises were surveyed twice per year, for six days in the last week of May and seven days in the third week of July, to collect morphometric, behavioral, life-history, and environmental data, including shell condition. The proportion of individuals with intact shells decreased from 91.4% in 2013 to 3.4% in 2024, albeit with annual fluctuations. This study revealed that various anthropogenic factors likely contribute to the increased proportion of tortoises with damaged shells in the study area, notably the intensification of regional and local transport alongside an overall rise in human presence. Natural pressures, such as increasing predator population sizes, may also contribute to this decline. In addition to overall changes in shell condition, the proportion of recorded tortoises affected by wildfires fluctuated annually from 0.4% to 81.9% and showed a large increase during the last 3 years of monitoring (the percentage of tortoises with identifiable fire marks on their shells averaged 53.73% for 2022–2024). Ultimately, these findings indicate rapid environmental changes in the study area, such as an increase in wildfires, increasing transport frequency, and a possible increase in the density of natural predators. These findings highlight the necessity for ongoing monitoring of this and other populations to ensure the prompt identification of new threats to this already imperiled species.