Latrine marking patterns of badgers (Meles meles) with respect to population density and range size

Christina D Buesching,Katrina Service,Philip Riordan,David W Macdonald,Chris Newman,R R Parmenter

doi:10.1002/ecs2.1328

Abstract

AbstractEuropean badgers (Meles meles) use shared defecation sites, termed latrines, to demarcate group ranges. While some latrines are small, comprising few pits with few fresh scats spread over a small area, others are large, comprising many pits with many fresh droppings and extending over a large area. Although many studies have investigated badger latrine usage patterns, and speculated on latrine function, this variation in relative latrine size remains unexplained. Using nearest neighbor analyses, we analyzed the latrine positioning, use, and inter‐latrine distances from four study areas with different population densities. We found that latrines were spaced regularly throughout the range, and border marking was prioritized, increasing the chances of traversing badgers intercepting a latrine. While the numbers of latrines increased with group range size, the number of fresh feces per latrine decreased, suggesting that fresh feces may be a limiting resource in the maintenance of latrines, and that maintaining latrine spacing pattern is more important than the actual number of fresh feces in each latrine. We thus posited that, where territories are small and groups large, the capacity to produce feces exceeds the minimum need for perimeter marking, resulting in fecal redundancy and large latrines. In contrast, in larger territories, especially when occupied by smaller groups, badgers may experience fecal constraint, thus maintaining smaller latrines. We concluded that latrine maintenance and fecal scent‐marking activity in badgers involves a trade‐off between group size and group range area, leading to different degrees of fecal constraint, while energetic costs of signaling are minimized.

Highlights

Scent-marking is a conspicuous element of the behavior of many carnivores (e.g., Brown and Macdonald 1985, Macdonald 1985, Gorman and Trowbridge 1989) where most exploit feces and urine, as well as the secretions of specialized glands (Johnson 1973, Gosling and Roberts2001), as olfactory signals
In WW, where the population density was between three-and six-times higher than in the other three areas, the linear relationship between number of latrines and group range size exhibited the steepest slope
As predicted by the Resource Dispersion Hypothesis (RDH), our findings support that the mechanism determining population density and group size is different from the mechanism determining group area, i.e., patch richness vs. patch dispersion

Summary

Introduction

Scent-marking is a conspicuous element of the behavior of many carnivores (e.g., Brown and Macdonald 1985, Macdonald 1985, Gorman and Trowbridge 1989) where most exploit feces and urine, as well as the secretions of specialized glands (Johnson 1973, Gosling and Roberts2001), as olfactory signals. In contrast to glandular secretions, which are often costly to produce (Alberts 1992, Gosling et al 2000), feces and urine are obligatory metabolic by-products of any heterotrophic diet They are readily available and “free” substances for scent-m arking (Gosling 1981, 1985, Macdonald 1985) that can be adapted to convey information about the v www.esajournals.org. While many solitary carnivores deposit single feces strategically to convey olfactory information to conspecifics, some group-living carnivores use communal latrines (reviewed by Buesching and Jordan in press). These are typically used by several, or all, group members, and generally appear to mark the interface between adjacent group ranges (Gittleman 1989). Understanding latrine marking patterns is important to understanding social carnivore societies and intergroup dynamics (for examples see Buesching and Jordan in press)

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Discussion

Conclusion