Abstract
Ecological and evolutionary constraints determine the solitary or social character of animal species, but certain solitary mammals such as bears or domestic cats show some social organization in areas with clumped food resources or in captivity (Fagen and Fagen 1990; Sunquist and Sunquist 2002). The European hedgehog (Erinaceus europaeus) is one of these cases (Figure 1); this solitary species is only found together during courtships, captivity conditions, or whenever plentiful food resources occur, such as human-provided food in gardens (Reeve 1994).