Wild boar deathbed choice in relation to ASF: Are there any differences between positive and negative carcasses?

African swine fever (ASF) is a fatal, infectious disease affecting wild boars and domestic pigs, mostly resulting in their deaths. Previous studies showed that carcasses of infected wild boars pose a serious threat for ASF virus transmission and leaving of dead bodies in the environment enables persistence of the disease in the given affected area. Therefore, the prompt finding and removal of the carcasses is crucial for effective ASF control. This study reveals habitat preferences of ASF-positive wild boars for their deathbeds, which could greatly improve the effectivity in the search for infected carcasses. The vast majority (71%) of carcasses were found in forests (although forests occupy only 26.6% of the high-risk area - Zlin region, Czech Republic), especially in young forest stands; 91.3% of infected wild boar carcasses, which were found in forests, were in stands of up to 40 years of age, where infected individuals search for calm and quiet places. The preference of younger forest stands is significantly higher for infected individuals (p< 0.001). On meadows, infected individuals preferred a higher herb layer (p = 0.002) compared to non-infected individuals. A higher preference of places more distant from roads and forest edges was observed for the infected individuals as well (p< 0.001 in both cases). No differences in deathbed habitat preference were observed between selected sex-age categories. The distance between carcasses and water source was observed to be dependent on current mean temperature. Carcasses were found closer to the water sources at higher mean temperature. Because of the comparable character of the landscape, presented models are applicable across Central Europe and have the potential to greatly facilitate the search for infected carcasses.