Small terrestrial mammals (Rodentia and Soricomorpha) along a gradient of forest anthropisation (reserves, managed forests, urban parks) in France

Abstract

Background: Understanding the relationships between wildlife biodiversity and zoonotic infectious diseases in a changing climate is a challenging issue that scientists must address to support further policy actions. We aim at tackling this challenge by focusing on small mammal-borne diseases in temperate forests and large urban green spaces. Small mammals are important reservoirs of zoonotic agents, with a high transmission potential for humans and domestic animals. Forests and large urban green spaces are ecosystems where efforts are undertaken to preserve biodiversity. They are put forward for their contribution to human well-being in addition to other ecosystem services (e.g. provisioning and regulating services). Moreover, forests and large urban green spaces are environments where small mammals are abundant and human/domestic-wildlife interactions are plausible to occur. These environments are, therefore, focal points for conservation management and public health issues.

New information: The European Biodiversa BioRodDis project (https://www6.inrae.fr/biodiversa-bioroddis) aims at better understanding the relationships between small terrestrial mammal biodiversity and health in the context of global change and, in particular, of forest anthropisation and urbanisation. Here, we present the data gathered in France. The dataset will enable us to describe the diversity of small terrestrial mammal communities in forested areas corresponding to different levels of anthropisation and to evaluate the variability of this diversity over time, between seasons and years.The dataset contains occurrences of small terrestrial mammals (Rodentia and Soricomorpha) trapped in forested areas in eastern France (administrative Departments: Rhône, Ain, Jura). The sampling sites correspond to different degrees of anthropisation. Forests included in biological reserves are the least anthropised sites. Then, public forests and urban parks experience increasing levels of anthropisation. Data were collected during spring and autumn 2020 (three to four sampling sites), 2021 (six sampling sites) and 2022 (four sampling sites). These variations in the number of sites between years were due to lockdown restrictions in 2020 or to the legal authorisation to trap around biological reserves granted in 2021 only. The capture of animals was carried out in various types of forests (pine, deciduous, mixed) and in different habitats within urban parks (wooded areas, buildings, hay storage yards, riverside vegetation, restaurants, playground for kids, botanical garden, landfills). Animals were captured using live traps that were set on the ground for one to 11 nights. During this study period, 1593 small mammals were trapped and identified. They belong to 15 species, amongst which were nine species of rodents (Muridae, Cricetidae, Gliridae) and six species of shrews (Soricidae). They were weighted (gram) and measured (cm): head-body length, tail length and hind-foot length. Sexual characteristics were also recorded.

Keywords: biodiversity; community; dilution effect; forests; global changes; rodents; shrews; urban parks.

Figure 1.

General map of the studied areas and their position in France. Localities are indicated by circles, red circles = urban parks; green circles = managed forests; light green circles = protected forests. FRPLTO: Lyon, Parc de la Tête d’Or; FRPDLL: Marcy l'étoile, Domaine Lacroix Laval; FRFCOR: Cormaranche en Bugey; FRFGRI: Arvière, La Griffe au diable; FRFMIG: Mignovillard; FRFGLA: Esserval-Tartre, La Glacière.

Figure 2.

Pictures of some of the trapping lines within each locality. FRPLTO: Lyon, Parc de la Tête d’Or; FRPDLL: Marcy l'étoile, Domaine Lacroix Laval; FRFCOR: Cormaranche en Bugey; FRFGRI: Arvière, La Griffe au diable; FRFMIG: Mignovillard; FRFGLA: Esserval-Tartre, La Glacière

Figure 3.

Maps of the trapping lines (red points) represented at a local scale for each of the following localities: A- FRPLTO: Lyon, Parc de la Tête d’Or; B- FRPDLL: Marcy l'étoile, Domaine Lacroix Laval; C- FRFCOR: Cormaranche en Bugey; D- FRFGRI: Arvière, La Griffe au diable; E- FRFMIG: Mignovillard; F- FRFGLA: Esserval-Tartre, La Glacière. The landscape around the trapping lines is represented by different colours corresponding to water bodies (blue; corine land cover 5), Forest and semi-natural areas (green, Forest database), artificial areas (grey; corine land cover 1) or other land-cover classes (white).

Figure 4.

Pictures illustrating the different steps leading to trapping and individual information. A- Preparation of traps (bait, cotton, trap number); B- An INRA trap sets in a forest; C- Meshed trap sets in a urban park; D- Trap checking in the morning (masks and gloves are important to protect animals and humans from zoonotic agents); E- Capture information recorded on a digital tablet (this picture was taken during the lockdown, which explains the mask); F- An INRA trap used to capture small mammals; G- A meshed trap containing a rat (Rattusnorvegicus); H- A plastic rest box containing a woodmouse (Apodemussylvaticus) that is released; I- Disinfection of traps (masks and gloves are important to protect humans from zoonotic agents).

Figure 5.

Pictures illustrating the different steps during small mammal dissection. Masks (FFP2), gloves and glasses protect the experimenter who manipulates and dissects the animals. A- All tubes are prepared in advance with unique identifier and datamatrix. One colour is dedicated to each type of sample (e.g. red tip for heart in PBS, purple tip for liver in RNA later). Morphological information was recorded on a paper sheet. Dissection instruments are disinfected between each animal. B- The experimenter is preparing the animal (here a brown rat Rattusnorvegicus) for the dissection. C- The experimenter is weighing the animal (here a woodmouse Apodemussylvaticus) for the dissection. D- A male common vole (Microtusarvalis). E- Tubes corresponding to liver samples, with unique identifiers and datamatrices, stored in a clearly identified box (unique identifier and datamatrix).