Diet/hair and diet/faeces trophic discrimination factors for stable carbon and nitrogen isotopes, and hair regrowth in the yellow-necked mouse and bank vole

We conducted a nonlethal feeding experiment to measure diet/hair and diet/faeces trophic discrimination factors (TDFs) in two rodent species fed two diet types. The mean TDFs between diet and hair (expressed as delta C-13/delta N-15) were 2.14 parts per thousand/3.44 parts per thousand for C3 plant-based fodder and 2.65 parts per thousand/3.25 parts per thousand for fodder with 30% animal (insect) matter in yellow-necked mice (Apodemus flavicollis) and 1.66 parts per thousand/4.67 parts per thousand for C3 plant-based fodder and 1.94 parts per thousand/4.49 parts per thousand for fodder with 30% animal (insect) matter in bank voles (Myodes glareolus). As compared with the diet, faeces were depleted in C-13 by about 0.75 parts per thousand and enriched in N-15 by about 2 parts per thousand. All bank voles and only half of yellow-necked mice had regrown hair at the end of the study (day 95). We analysed archived skins of those species and confirmed, that moult in bank voles is more intensive. Our results can be used for trophic studies of temperate-forest rodents and for meta-analyses on trophic discrimination.

Automated summary

We conducted a nonlethal feeding experiment to measure trophic discrimination factors (TDFs) in two rodent species fed different diets. The study found that yellow-necked mice and bank voles had different TDFs and showed variations in their fecal isotopic composition. Additionally, the moult intensity differed between the two species.