Substantial niche overlap in carrion beetle habitat and vegetation use

Abstract

Abstract The habitat affinities of carrion beetles (Coleoptera: Silphidae), a speciose group with wide cooccurrence, are only coarsely described for well‐studied species, particularly in the western United States. We aim to identify if the 15 species of montane carrion beetle in Colorado differ substantially in their use of habitats and across more uniquely defined, fine‐scale vegetation characteristics. Habitat and vegetation data as well as carrion beetle abundance were collected along four elevational transects in the Front Range and San Juan Mountains from 2010 to 2012 across 32 sites. Multiple habitat types were sampled, including forest, meadow, riparian, rocky outcrops and tundra. The fine‐scale vegetation characteristics included percent coverage of ground vegetation (grass, forb, shrub, cacti, bare ground), understory vegetation biomass and height, canopy cover and tree species, number and size. Canonical correspondence analysis models examined whether vegetation characteristics strongly segregated species using abundances and presence‐absences. Habitat and vegetation models explained a maximum of 18.93% of the variation in species' abundances and 2.48% in species' presence–absences. Only one likely habitat specialist was identified by the models (Heterosilpha ramosa) and the remaining species had substantial overlap in habitat and vegetation use. The arid, low productivity and generally open understory habitats in Colorado mountains likely play a large role in the substantial vegetation overlap. Other mechanisms of partitioning likely exist in this system to reduce niche overlap, which could include differences in activity time and seasonality, physiological traits, other life history strategies and body size.