Stress and the City: Body Condition, Blood Parameters, Parasite Load, and Stomach Calorimetry of Rural and Urban European Rabbit Populations

(1) Background: We combined physiological and morphological data of the European rabbit (Oryctolagus cuniculus) to provide insights into the question of how urbanization affects the health of urban wildlife populations. (2) Methods: We dissected 39 urban and 34 rural wild rabbits in order to compare organ weights, as well as stomach contents. Furthermore, we collected blood and fecal samples. (3) Results: Rural rabbits had a significantly longer body and a higher body weight as well as more fat tissue around their kidneys compared to urban rabbits. In contrast, the stomach, the intestines, the liver, the lung, and the brain of urban rabbits were significantly heavier. The amount of hematocrit, hemoglobin, and the mean corpuscular volume was significantly higher in urban rabbits. The caloric energy content of the stomach was comparable between rural and urban rabbits and was merely influenced by the season being higher in autumn. Rural rabbits had an overall higher mean parasite index compared to urban rabbits. (4) Conclusions: The results of our study allow for a deeper understanding of how density-dependent (e.g., transmission of diseases) and density-independent factors (e.g., food quality) influence the health status and life history traits of urban wildlife populations compared to their rural counterparts.