Dung Beetles of the Western Palaearctic

Study Extent

The multi-site experiment was carried out on 17 study sites covering 10 countries (Belgium, Estonia, France, Germany, Hungary, Iran, Norway, Romania, Spain and the United Kingdom). Each study site was assigned to a biogeographic region according to Udvardy (1975). When possible, the experiment was replicated on a spatial scale by selecting study sites within the same biogeographic region, and on a temporal scale by replicating the experiment in different seasons and/or years. All study areas consisted of natural grasslands which had been grazed by domestic and/or wild herbivores for at least a couple of years prior to the experiment.

Sampling

During the experiments, the dung beetle community was sampled in each study area. In 2013 and 2014, two main types of pitfall traps were used in order to achieve a complete view of dung beetle diversity and abundance. The first trap type consisted of one large container (1 l) with a 11 cm wide opening at the top, and covered with hexagonal chicken wire (with mesh diameter of 25 mm) and dung as bait (as described in Larsen, Forsyth (2005)). In sampling campaigns in 2013 and 2014, approximately 100 g of dung packed in a nylon bag was put on top of the chicken wire (sampling protocol "T1" in the dataset), while in 2015 the traps were baited with a larger amount of unwrapped dung (ca. 500 g) put directly on the chicken wire (sampling protocol "T1L"). The second trap type consisted of five smaller containers (0.2 l) with a 7 cm wide opening at the top, and surrounding a central dung pile of approximately 300 g (as in D'hondt et al. (2008), sampling protocol "T5"). In all trap types containers were dug into the soil with the upper rim levelled with the soil surface. Containers were filled with a saturated salt-water solution (ca. 365 g l-1 NaCl with some drops of unscented detergent). All pitfall traps were set up randomly between the experimental units with six replicates per dung type used in the dung removal experiment. Traps were put in operation one week after the start of the dung removal and seed dispersal experiments in order to avoid interference with the initial beetle colonization phase of the experiment. Traps were emptied weekly and sampling stopped after one month, equalling three sampling occasions per experimental period.

Method steps

1. Dung beetle specimens were extracted from the samples and identified at species level.
2. For each species, the number of individuals was counted per sampling unit (pitfall) with indication of sampling date, used dung bait and geographic location.

We defined 'dung beetles' as species of the superfamily Scarabaeoidea that generally feed on dung in both the larval and adult phase. Some species of other beetle families such as Hydrophilidae and Staphylinidae are commonly found in dung as well and could be considered as dung beetles as well (Hanski, Cambefort 1991). Nevertheless, they are not coprophagous during their entire life cycle (Finn et al. 1999) and they do not contribute to lateral or vertical dung transport which was one of the major research questions in our study. Therefore, dung beetles were strictly defined as the coprophagous species in the Geotrupidae and Scarabaeidae families.

1. Coleoptera
   common name: beetles rank: order
2. Scarabaeoidea
   rank: superfamily
3. Scarabaeidae
   rank: family
4. Geotrupidae
   rank: family

The multi-site experiment was carried out on 17 study sites covering 10 countries in the Western Palaearctic realm. All study areas consisted of natural grasslands which had been grazed by domestic and/or wild herbivores for at least a couple of years prior to the experiment.