Where do hamsters go after cereal harvest? A case study.

Abstract

Agricultural intensification in recent decades has led to a major loss of biodiversity in agricultural landscapes. Special agri-environmental schemes aim at restoring and protecting biodiversity. In Central Europe, the common hamster Cricetus cricetus (Linnaeus, 1758) is a prominent victim of changes in agricultural management and land-use. After cereal-harvest, common hamsters are deprived from shelter and food sources and little is known on how individuals cope with these changes. We investigated how a population of common hamsters use agricultural landscapes after cereal harvest in 45 fields within a distribution hotspot of the common hamster in Central Germany. We recorded hamster burrow densities before and after cereal harvest in the winter cereals as well as in the two most important specialty crops in the study region, red cabbage and carrot. Common hamster burrows were more abundant in cereals than in the specialty crops before harvest. After cereal harvest, common hamster burrow densities decreased in cereal fields and increased in carrot but not red cabbage. Carrot fields thus provide alternative habitat for common hamsters after cereal harvest. Since many carrot cultivars are harvested in late autumn, these fields potentially provide a safe habitat for hamsters until hibernation. We recommend a targeted subsidizing of the cultivation of late harvest carrot cultivars in regions where common hamster conservation is a priority. These fields should be placed strategically and in sufficient quantities in focus landscapes. Other specialty crops could potentially also help in targeted protection schemes but whether and how they can benefit common hamsters after the cereal harvest needs further investigation.