Weeds as a predominant food source: a review of the diet of common hamsters Cricetus cricetus in farmlands and urban habitats.

The common hamster Cricetus cricetus was long considered to be a pest species for crops, but its populations are now dramatically declining. The conservation of this species can only be achieved via an up‐to‐date knowledge of its ecology. However, its diet composition has never been exhaustively reviewed and the last peer‐reviewed publication on its feeding ecology in farmlands dates back to 1974.This review of the literature aims to establish a list of plant and animal taxa consumed by common hamsters, providing knowledge to be applied to the conservation of hamsters and to identify the main avenues of future research.Hamsters consume four main categories of food: crops, weeds, trees/shrubs and animals, including mammals, birds, herptiles and invertebrates. Vegetable foods are more diverse (114 taxa) than animal foods (11 taxa). Hamsters mainly consume animals and green parts of plants (flowers and leaves) in spring and summer, and store energy‐rich and non‐perishable foods for winter.Weeds are the most diverse food category (61 taxa), followed by crops (31 taxa). However, diet shifts from crop products towards tree products in urban habitats, probably in response to a marked difference in availability.We conclude that hamsters have an opportunist diet that shows a high degree of plasticity, and that weeds make up an important part of their food supply. However, the studies published to date have considered diet composition without taking food availability into account, and therefore lack information on whether the hamsters select the foods consumed or simply consume them because other foods are not readily available. Research on food availability and selection is therefore needed. Moreover, we argue that there is a need for recent data on the feeding ecology of the hamster in relation to fitness. This would provide a crucial tool for the implementation of adapted conservation measures for this declining species of rodent. [ABSTRACT FROM AUTHOR]