No abstract

Species invasions are expected to increase continuously with undeniable impact upon native biodiversity, being an important process in relation to the decline of native pollinators. We used species distribution models and multivariate analyses to assess the climatic niche properties of the red dwarf honey bee, Apis florea Fabricius (Apidae: Apini), an open-nesting species native to southern Asia and parts of the Middle East, currently invading East Africa, Sundaic tropical Southeast Asia (Peninsular Malaysia and Singapore), and East Asia (Taiwan). The species' niche was relatively conserved, with the climatic conditions in all its invaded range overlapped by those from its native one. Its potential distribution in Africa and the Indomalayan region is broad, with anthropogenic areas likely providing new habitats and dispersal corridors in areas that were formerly too arid or too heavily forested to allow its dispersal. Future studies to evaluate the potential impacts of A. florea in invaded ranges are encouraged. species distribution models / macroecology / invasion process / Asia / Africa

Baited pitfall traps (BPTs) and flight intercept traps (FITs) are the most common methods employed for sampling dung beetle communities. These methods vary in their efficacy and are affected by factors such as the bait types used and the dispersal abilities of different dung beetle species. We present the first quantitative comparison of the community composition, taxonomic and functional diversity of dung beetles caught in human dung BPTs and FITs in Bornean tropical forests. Functional diversity metrics were calculated based on the three functional traits of nesting method, body length, and diel activity. We show that BPTs and FITs captured complementary communities with different functional traits, and that BPTs captured more functionally diverse communities. We therefore recommend using a combination of both BPTs and FITs for studies assessing the composition of dung beetles across habitat types. Our results also highlight that it is important to consider how trap type affects the trait composition of communities when relating dung beetle communities and functional traits to ecological functioning. We suggest modifications to FITs based on the design of harp traps to increase their effectiveness in capturing larger-bodied beetles.

SouthEast Asia's natural habitats are lowland tropical rainforests that harbor a large proportion of the Earth's biodiversity. These rainforests are affected by multiple drivers of biodiversity loss, including deforestation and hunting (Sodhi et al., 2004), with habitat loss being the major driver of species extinctions (Achard et al., 2002). Such large-scale anthropogenic disturbances are driving the extirpation of many large mammals (Bennett, 2000; Sodhi et al., 2004; Steinmetz et al., 2006; Corlett, 2007), resulting in potential cascading effects in tropical rainforest systems, such as secondary extinctions of dependent taxa and the subsequent decline of ecological processes performed by these associated species (Nichols et al., 2009). Scarabaeine dung beetles (Coleoptera: Scarabaeoidea) rely primarily on mammal dung as a food resource for adult beetles and their larvae (Hanski & Cambefort, 1991). Their diversity of dung manipulation, relocation, and consumption contributes to a series of beneficial ecosystem functions and services to tropical rainforests, such as secondary seed dispersal and nutrient cycling (Nichols et al., 2008). Thus, declines in mammal populations, resulting in reduced availability and changing composition of dung resources in tropical rainforests, are predicted to lead to changes in dung beetle communities and cascading effects for ecosystem functioning in these systems (Nichols et al., 2009; Raine & Slade, 2019). Recent work has shown that most dung beetles are generalists when foraging (Frank et al., 2018). However, even generalist dung beetle species have been shown to differentiate variations among differing dung compositions, size, and shape, and display preferences for certain dung types (Peck & Howden, 1984; Nichols & Gardner, 2011; Raine et al., 2019). Moreover, while dung beetle-mammal co-occurrences have been relatively well studied in the Neotropics (e.g., Bogoni et al., 2014; 2019; Nichols et al., 2016), dung beetle-mammal interactions are little explored in SouthEast Asia's forests (Frank et al., 2018; Raine & Slade, 2019). While co-occurrence data shed light on the possibility of such interactions, these can only be quantified by assessing the specific attractiveness of different dung types to individual species, and building quantitative networks (Frank et al., 2018; Raine & Slade, 2019). The first quantitative dung beetle-mammal network for a tropical forest region has recently been built for the Atlantic forest