Dung Beetle Diversity and Community Composition Along a Land Use Gradient in a Savannah Ecosystem of North Western Tanzania

Abstract

Habitat loss and degradation are the most widely cited drivers of changes in species abundance and diversity. We explored changes in dung beetle species diversity and composition across different land uses in the north west Tanzanian savannah. We expected a negative response gradient in the diversity and composition of the dung beetle community, from land uses that preserve vegetation and hold native mammal diversity to livestock intensive and heavily grazed areas. Dung beetles were sampled in a protected area and two anthropogenically influenced land use types. Species richness and composition of each land use type, including differences in diversity and functional groups were analyzed and indicator species for each land use gradient were identified. As expected, diversity and community composition varied between areas with less environmental change compared to those impacted anthropogenically. We conclude that conservation of protected areas within African savannahs can provide a functionally rich dung beetle community and subsequently rich ecological functions. The dung beetle species identified by this study as eco-indicators can be used as a benchmark for future studies that use rapid monitoring to assess disturbance in African savannas.

Dung beetle community assemblages in a southern African landscape: niche overlap between domestic and wild herbivore dung

“…The R package ‘indicspecies’ (De Cáceres and Legendre, 2009) was used to calculate the IndVal index between dung beetle species and pitfall trap groups, and to identify groups with the highest species association values. The IndVal index is a value between 0 and 1, and species with a value of ≥0.75 were considered indicators for a group, 0.5–0.75 of showing a degree of association and ≤0.5 indicating no association or generalist behaviour (subjective benchmark; Tshikae et al ., 2008; Stanbrook et al ., 2021). Permutation tests ( n = 999) were then performed, and species with high (≥0.75) and significant IndVals were considered specialists for that group.…”

“…Dung beetles in the subfamily Scarabaeinae are a diverse and abundant component of the savannah ecosystem in sub-Saharan Africa, which supports some of the richest and most diverse mammalian communities in the world (Nieto et al ., 2005; Tshikae et al ., 2008). The majority of African Scarabaeinae is tunnelling (paracoprid) beetles, which comprise approximately 70% of species found (Davis et al ., 2008; Stanbrook et al ., 2021). However, ball-rolling species (telocoprid) and species which colonize and breed in the dung balls of other beetle species (kleptocoprid) may also be abundant (Davis et al ., 2008).…”