Diversity and Diet Differences of Small Mammals in Commensal Habitats

Abstract

The stability of diversity of syntopic (inhabiting the same habitat in the same time) small mammals in commensal habitats, such as farmsteads and kitchen gardens, and, as a proxy of their diet, their isotopic niches, was investigated in Lithuania in 2019–2020. We tested whether the separation of species corresponds to the trophic guilds, whether their diets are related to possibilities of getting additional food from humans, and whether their diets are subject to seasonal trends. We analyzed diversity, dominance and distribution of hair δ13C and δ15N values. Diversity and dominance was not stable and differed according to human influence. The highest small mammal species richness occurred in commensal habitats that provided additional food. The degree of separation of species was higher in homestead habitats than in kitchen gardens, where a 1.27 to 35.97% overlap of isotopic niches was observed between pairs of species. Temporal changes in δ13C and δ15N values in the hair of the mammals were not equally expressed in different species. The isotopic overlap may depend on dietary plasticity, minimizing interspecific competition and allowing co-existence of syntopic species. Thus, small mammal trophic ecology is likely related to intensity of agricultural activities in the limited space of commensal habitats.

An Experimental Study in Wild Wood Mice Testing Elemental and Isotope Analysis in Faeces to Determine Variations in Food Intake Amount

“…This depletion in faecal δ 13 C values as compared with the diet has been also reported by other works carried out with several rodents, including the yellow-necked mouse Apodemus flavicollis [ 49 , 66 ]. Furthermore, both elemental and isotopic values found for the wood mouse in this study are consistent with the ranges found for other rodent species both in faeces [ 34 , 49 , 66 , 67 , 68 , 69 , 70 ] and hair samples [ 67 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 ]. Furthermore, the faecal isotopic composition of wood mouse faeces found also falls within values reported in the few available scientific works addressing hair and blood isotopic composition in the wood mouse [ 51 , 52 ].…”

Stable Isotope Analysis Supports Omnivory in Bank Voles in Apple Orchards

“…In our context, this means that the populations of C. glareolus in the apple orchards might be augmented from the nearest habitats. However, as C. glareolus in orchards and commensal habitats are very close to human settlements [19], these aspects might be of importance in hantavirus transmission [72,73].…”

“…The bank vole (Clethrionomys glareolus), also known as Myodes glareolus [15], is a small mammal species widespread in the Palaearctic and inhabits various woodlands, shrubby areas and parklands [16]. In Lithuania, it is very widespread and numerous, found in all forest habitats, lakeshores, shrubby meadows and reedbeds [17,18], as well as agricultural and commensal habitats [14,19]. In orchards, C. glareolus can cause damage by gnawing bark [20] and, thus, knowledge of its diet might have practical significance.…”

Advances in Diversity and Conservation of Terrestrial Small Mammals

“…The analysis of the trophic ecology and diversity of small mammals among syntopic species in commensal habitats (homesteads and gardens) in the northern part of the midlatitudes was based on the first data presented in [9]. The authors aimed to determine whether the separation of species corresponds to specific trophic guilds, whether their diets are influenced by the availability of additional food from humans, and whether their diets exhibit seasonal trends.…”