Dung Beetle Abundance Research Articles

Diversity of Scarabaeinae (Coleoptera: Scarabaeidae) in an urban fragment of Cerrado in Central Brazil

The diversity of dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) is affected by urbanization, habitat fragmentation and disappearance of native mammals, which result in changes in the quality and availability of food, and resources for nesting. We evaluated the diversity, distribution of species in different trophic guilds and foraging strategies, and temporal variation in abundance of dung beetles in an urban fragment of Cerrado in a Federal District of Brazil. This study was conducted at the Experimental Station of Biology (EEB) of the University of Brasilia (UnB), Federal District, Brazil. Fortnightly, between October 2012 and September 2013, Scarabaeinae were collected using baited (human faeces, pig meat, or banana) and unbaited pitfall traps. Aspects of the dung beetle assemblage were evaluated, including species richness and abundance, feeding habits and foraging strategies. A total of 614 individuals were collected, which included eight species belonging to seven genera and four tribes. Dichotomius carbonarius (Mannerheim, 1829), a generalist species, dominated the assemblage, indicating that it is adapted to living in fragmented and urbanized areas. As regards feeding habits, Eurysternus caribaeus (Jablonsky & Herbst, 1789) was considered to be strictly coprophagous, Coprophanaeus cyanescens (d'Olsoufieff, 1924) copronecrophagous and D. carbonarius a generalist. Most species were classified as paracoprids, which accounted for 75% of the species collected. Regarding the attractiveness of the bait, the highest numbers of individuals and species were recorded in pitfall traps baited with human faeces. A high abundance of Scarabaeinae was recorded in the first half of the rainy season (October-December) with 98.2% of the individuals collected in this period. The urban area studied harboured a low number of species with high abundance of a few species.

Dung beetles of an Australian tropical savanna: Species composition, food preferences and responses to experimental fire regimes

AbstractDung beetles are an ecologically important group of insects globally, but the ecology of the Australian fauna is poorly known. Here, we report on the first ecological study of dung beetles in an Australian tropical savanna, documenting species composition, food preferences and responses to fire. Dung beetles were baited using dung from five types of vertebrates as well as mushrooms. We sampled at nine plots subject to experimental fire regimes (three replicates each of high fire severity, moderate fire severity and unburnt over 15 years) at the Territory Wildlife Park near Darwin. Our samples were comprised entirely of nine native species of Onthophagus. Dog dung was the most attractive bait, recording all nine species and nearly 80% of all individuals, whereas no beetles were recorded at either wallaby or magpie‐goose dung. Dung beetle abundance was highest under high fire severity and was negatively correlated with the cover of woody vegetation, a result driven by the two most common species, O. minsiculus and O. nr. quadripunctulatus. Our results indicate that Onthophagus is the dominant genus in dung‐beetle assemblages of monsoonal Australia, as it is in open habitats of the Australian wet tropics. All our species of Onthophagus are relatively small (≤10 mm body length) and are ‘tunnellers’, storing dung and other food resources in tunnels dug immediately below the food source. Such an overwhelming dominance by small tunnellers does not occur in African savannas, reflecting the far lower availability of large mammalian dung in Australia.

Habitat patch size and isolation drive the near-complete collapse of Amazonian dung beetle assemblages in a 30-year-old forest archipelago

The creation of mega-hydropower dams inundates vast lowland areas, causing widespread environmental impacts in tropical forest regions. Few studies, however, have taken advantage of these newly fragmented landscapes to examine the effects of habitat insularization on arthropod faunas. Here, we assess how dung beetle assemblages respond to 30 years of post-isolation history in forest islands within a major hydroelectric reservoir in Central Amazonia. We sampled 30 of the 3546 islands created by this reservoir, and three neighbouring forest sites. We collected a total of 865 individuals representing 34 dung beetle species and 15 genera. Remarkably, one third of all islands had been entirely defaunated of dung beetles in terms of overall occupancy. Isolation was the single best predictor of dung beetle species richness, followed by the interaction between isolation and island area, and these variables were key determinants of the relict species composition. Isolation was the most important predictor of dung beetle abundance, but area alone was the main predictor of abundance when the dominant species was excluded. We predicted species richness across all 3546 islands, indicating that 61.5% of all islands likely retain only a single ‘super-tramp’ species (Onthophagus osculatii). These community disassembly patterns were likely aggravated by the marked hostility of the open-water matrix combined with the poor flight dispersal capacity of dung beetles over wide gaps between insular forests. As such, the overwhelming number of small, isolated islands created by major dams has profound effects on regional forest biodiversity, including wholesale local extinctions in detritivore assemblages and their ecosystem functions.

Successional trajectory of dung beetle communities in a tropical grassy ecosystem after livestock grazing removal

Grazing by large herbivorous mammals is still a structuring force in tropical grassy ecosystems, and cattle grazing is one of the main economic activities carried out in these ecosystems in modern times. Therefore, understanding the impacts of cattle grazing removal on biodiversity may be a key step for conservation of this ecosystem. Here, we studied the successional trajectory of dung beetle communities in a tropical grassy ecosystem after cattle removal. For this, we assessed the patterns of dung beetle taxonomic and functional diversity of 14 natural grasslands with distinct cattle grazing removal ages (from 3 months to 22 years) along a chronosequence, applying the space-for-time substitution method. Our results show a strong decrease in dung beetle abundance (93 times) and species richness (6 times) in the first ten years of cattle removal. However, after ten years there is an increase in dung beetle abundance (73 times) and species richness (5 times). Taxonomic composition was also influenced by cattle removal time demonstrating the importance of cattle in the structuring of dung beetle communities in natural grasslands. In contrast, functional composition and diversity were not affected by cattle grazing removal, indicating these metrics are less sensitive to cattle absence than taxonomic diversity and composition. Our results provide evidence that cattle grazing removal, at least in the short term (10 years), may be an inefficient management tool for restoration and conservation of tropical grassy ecosystems. However, we highlight the need to investigate the reintroduction of cattle grazing after different removal times to provide complimentary information to livestock management able to integrate human use and conservation of tropical grassy ecosystems.

Implications of Endectocide Residues on the Survival of Aphodiine Dung Beetles: A Meta-Analysis.

It is often difficult to compare studies examining the effects of endectocides on dung fauna because of different experimental approaches, for example, active ingredients (eprinomectin, doramectin, ivermectin, moxidectin) and formulations (injectable, pour-on, spiked). To gain a better understanding, we performed a quantitative meta-analysis using 22 studies to assess the overall effect of endectocide residues on the occurrence (presence or absence) and abundance of aphodiine dung beetles. Our results document a positive effect on the occurrence of adult beetles, indicating that adults tend to be attracted to dung with residues. Conversely, larvae are less likely to occur in the presence of residues. Thus, either adults that colonize dung with residues do not lay eggs or, more likely, the larvae that hatch from these eggs die early in development. Abundance of adult and larval stages was shown to be significantly reduced in dung containing residues. When individual endectocides were compared, only ivermectin demonstrated a significantly negative effect on the abundance of both adults and larvae, possibly owing to a small sample size for other agents. In laboratory studies, only dung "spiked" with endectocides reduced the abundance of larvae, whereas during field research, only pour-on applications were shown to reduce the abundance of larvae. The present study further documents the nontarget effects of endectocide residues on dung-dwelling organisms, provides robust evidence on the consequences of different application methods, and emphasizes the need for standardized methodological techniques in future studies. Environ Toxicol Chem 2020;39:863-872. © 2020 SETAC.

Forest habitat parameters influence abundance and diversity of cadaver-visiting dung beetles in Central Europe.

Dung beetles provide crucial ecosystem services and serve as model organisms for various behavioural, ecological and evolutionary studies. However, dung beetles have received little attention as consumers of large cadavers. In this study, we trapped copronecrophagous dung beetles on above-ground exposed piglet cadavers in 61 forest plots distributed over three geographically distinct regions in Germany, Central Europe. We examined the effects of land use intensity, forest stand, soil characteristics, vascular plant diversity and climatic conditions on dung beetle abundance, species richness and diversity. In all three regions, dung beetles, represented mainly by the geotrupid species Anoplotrupes stercorosus and Trypocopris vernalis, were attracted to the cadavers. High beetle abundance was associated with higher mean ambient temperature. Furthermore, A. stercorosus and T. vernalis were more abundant in areas where soil contained higher proportions of fine sand. Additionally, an increased proportion of forest understorey vegetation and vascular plant diversity positively affected the species richness and diversity of dung beetles. Thus, even in warm dry monocultured forest stands exploited for timber, we found thriving dung beetle populations when a diverse understorey was present. Therefore, forestry practices that preserve the understorey can sustain stable dung beetle populations and ensure their important contribution to nutrient cycles.

Diversity of dung beetle (Coleoptera: Scarabaeidae) in oil palm agropasture ecosystem in West Kotawaringin Regency, Central Kalimantan, Indonesia

Cattle grazing on oil palm plantation (agropastoral) has the potential to increase biodiversity by providing new habitats and providing foods for invertebrates. Dung beetles use the cattle’s dung for food and to lay eggs. The aim of this research is to study the effect of cattle grazing on oil palm plantation toward the diversity, abundance and ecosystem services of dung beetles. The research was conducted in the oil palm plantation of PT. Astra Agro Lestari Tbk. Central Kalimantan Province. Samplings were done on 6 oil palm blocks (4 plots on each block) consisting of 3 blocks that have been grazed by cattle (agropastoral) and 3 blocks that were not grazed (non-agropastoral). Samplings were done using baited pitfall traps and dung removal test. The treatments were replicated 4 times (0, 4, 8 and 12 wk). In total 24 species belonging to 5 genera and 11 019 individuals dung beetle have been collected. The most diverse group were genera from Onthophagus (16 species; 66.7% of collected species) and follow by Aphodius (4 species; 16.6%), Catharsius (2 species; 8.3%), Panelus (1 species; 4.2%) and Oniticellus (1 species; 4.2%). The result showed that the diversity of dung beetle was the same in agropastoral and non-agropastoral, but the abundance was 4 times higher in agropastoral habitat. Dung removal in non-agropastoral was 16% higher than agropastoral. Overall the result showed that cattle grazing has increased dung beetle population, although it has no effect on the diversity and ecosystem service of dung beetle.

Spatial and temporal changes in the dung beetle diversity of a protected, but fragmented, landscape of the northernmost Neotropical rainforest

Abstract Studies addressing the temporal changes of ecological communities within fragmented forests transformed into natural protected areas are urgently needed. The creation of the Los Tuxtlas Biosphere Reserve (LTBR) in 1998 stopped the deforestation process of the northernmost tropical rainforest of the Neotropical region, allowing the analysis of the long-term effects on native communities after the halting of habitat fragmentation. We compared the diversity of dung beetles in 11 forest fragments and eight pastures in the LTBR between two periods: 1999–2000, the early years after the creation of the LTBR; and 2016–2017, i.e., 17 years later. Species richness and abundance of dung beetles were similar in both periods, being higher in forest fragments than in pastures; however, the dominant species were different in each period in both forest fragments and pastures. The number of habitat indicator species increased in 2016–2017 compared to 1999–2000, with a high species diversity of forest indicators relative to pasture indicators at both periods. Alpha and gamma diversities were lower in 1999–2000 than in 2016–2017. Beta-diversity at the spatial level was strongly driven by species turnover, which was higher in pastures than in forest fragments. All functional groups (dwellers, rollers, and tunnellers) showed higher abundances in forest fragments than in pastures in both 1999–2000 and 2016–2017 periods. Our results suggest that stopping the fragmentation process in the LTBR has allowed the survival of native dung beetle assemblages, which are undergoing a recovery process of their populations and ecological functions over the years.

Initial Responses of Dung Beetle Communities to Bison Reintroduction in Restored and Remnant Tallgrass Prairie

Restoration is a critical component of grassland conservation worldwide, but grassland management requires disturbances that maintain the habitat. Further, successful restorations need to support not just a vegetative community, but also a diverse community of other organisms that contribute to a range of ecosystem functions. Large herbivore grazers like American bison (Bison bison) can be an important part of these management strategies, but their role in functions like nutrient cycling relies in part on dung beetles (Scarabaeidae: Scarabaeinae and Aphodiinae, and Geotrupidae), which provide valuable ecosystem services by removing and burying dung. We evaluated dung beetle community responses and dung decomposition in restored and remnant prairies shortly (1.5 y) after bison reintroduction. Dung beetle abundance was significantly greater where bison were present, where prescribed fire had been applied in the past year, and in older restorations and remnants. These same environmental characteristics also shifted the composition of beetle communities, but not total community biomass, as the increased abundance was driven by small-bodied species. Dung decomposition varied with bison presence and site age, with the highest rates of decomposition in an old restoration with bison present. These results indicate that dung beetle communities are capable of rapidly responding to bison introduction, a promising sign that land managers may be able reestablish ecosystem-level processes driven by large grazers in restored grasslands.

Impacts of an indigenous settlement on the taxonomic and functional structure of dung beetle communities in the Venezuelan Amazon

In the last 50 years, traditionally nomadic indigenous communities in Amazonia have increasingly adopted more sedentary lifestyles as a result of external influences. Permanent settlements lead to the concentration of disturbances (e.g., forest extraction and hunting) and threaten vulnerable species as well as those that provide important ecosystem services such as dung beetles. Here we evaluated the abundance, taxonomic, and functional structure (composition and diversity) of an ecological indicator group—dung beetles—along a disturbance gradient associated with a permanent settlement of the Joti people in the Amazonian region of Venezuela. We applied generalized linear model to assess the response of dung beetle abundance to settlement distance and latent variable model to assess the influence of settlement distance on taxonomic diversity and functional structure. We found the abundance of roller-species increased but small-bodied beetles decreased away from the settlement. We found that proximity to the Joti settlement did not affect metrics of taxonomic and functional diversity of the dung beetle assemblages in general, although functional evenness was lower away from the settlement. In contrast, we found impacts on the functional composition of dung beetles, with significant increase in the community-weighted means for roller species and large-bodied dung beetles away from Joti settlement. Our findings suggest that the transition from nomadism to a more sedentary lifestyle has not caused widespread collapse in the diversity of dung beetle assemblages surrounding the settlement, however significant trends were observed in species-specific responses to human impact, and these responses were mediated by functional traits.

Climate rather than dung resources predict dung beetle abundance and diversity along elevational and land use gradients on Mt. Kilimanjaro

AbstractAimWhile elevational gradients in species richness constitute some of the best depicted patterns in ecology, there is a large uncertainty concerning the role of food resource availability for the establishment of diversity gradients in insects. Here, we analysed the importance of climate, area, land use and food resources for determining diversity gradients of dung beetles along extensive elevation and land use gradients on Mt. Kilimanjaro, Tanzania.LocationMt. Kilimanjaro, Tanzania.TaxonScarabaeidae (Coleoptera).MethodsDung beetles were recorded with baited pitfall traps at 66 study plots along a 3.6 km elevational gradient. In order to quantify food resources for the dung beetle community in form of mammal defecation rates, we assessed mammalian diversity and biomass with camera traps. Using a multi‐model inference framework and path analysis, we tested the direct and indirect links between climate, area, land use and mammal defecation rates on the species richness and abundance of dung beetles.ResultsWe found that the species richness of dung beetles declined exponentially with increasing elevation. Human land use diminished the species richness of functional groups exhibiting complex behaviour but did not have a significant influence on total species richness. Path analysis suggested that climate, in particular temperature and to a lesser degree precipitation, were the most important predictors of dung beetle species richness while mammal defecation rate was not supported as a predictor variable.Main conclusionsAlong broad climatic gradients, dung beetle diversity is mainly limited by climatic factors rather than by food resources. Our study points to a predominant role of temperature‐driven processes for the maintenance and origination of species diversity of ectothermic organisms, which will consequently be subject to ongoing climatic changes.

Morphological traits reflect dung beetle response to land use changes in tropical karst ecosystems of Vietnam

Abstract Dung beetles (Coleoptera, Scarabaeidae) are known to respond sensitive to habitat changes, but difficulties in the delineation of species together with their high local diversity have hindered the generalization of results. Morphological traits instead may better reflect species’ adaptations to habitat changes. We investigated changes in morphological traits of 41 tunnelling dung beetle species in a sequence of land use change from primary forests, to secondary forests and meadows in a tropical karst mountain ecosystem in Vietnam (South East Asia). Tunnellers were by far the dominant functional group of dung beetles in these ecosystems. In addition, we measured dung removal rate as a key ecosystem service of these beetles. By combining RLQ and fourth-corner methods to characterize shifts in morphological species traits, we identified three distinct morphological trait clusters of dung beetles, reflecting distinct community adaptations to land use changes. Meadows, despite harbouring highest dung beetle abundance and species richness were severely impoverished in large-bodied dung beetles. The large-bodied dung beetles however, turned out to play crucial roles for dung removal. These data indicate that land use change led to significant changes of species traits in dung beetle communities which in turn fed back on critical ecosystem services. Our data demonstrate that trait-based approaches are well suited to describe the functional implications of environmental changes on species-rich arthropod communities and may better allow generalizations of adaptive responses between ecosystems.

Effects of herd management and the use of ivermectin on dung arthropod communities in grasslands

Agroecosystems represent a large geographical footprint in most terrestrial landscapes, and management decisions within these systems affect their function in species conservation. We evaluated the effects that rangeland management systems (based on stocking density, rotation frequency, and the number of avermectin applications) have on conserving the dung arthropod community in the Northern Great Plains of North America. Comprehensive bioinventories of arthropods were collected from 16 rangelands using core samples of dung pats. Ivermectin was quantified in pats from each ranch using enzyme-linked immunosorbant assay (ELISA). Arthropods in dung were abundant (116,244 specimens) and diverse in eastern South Dakota (172 morphospecies). Rangelands managed with more regenerative practices (frequent rotation at high stocking densities and lack of ivermectin applications) had greater species richness, diversity, predator species abundance, and dung beetle abundance than more conventionally managed rangelands. Ivermectin quantity in cattle pats was negatively correlated with dung beetle abundance and diversity. This work shows that herd management (specifically high-intensity, frequent rotational grazing and eliminating prophylactic ivermectin use) that aims to mimic intensive grazing of large migrating herds of ruminants can foster dung arthropod community structure, a key trait correlated with nutrient cycling, pest suppression, and productivity of cattle-grazed rangelands.

Forest complexity drives dung beetle assemblages along an edge‐interior gradient in the southwest Amazon rainforest

1. The habitat heterogeneity hypothesis predicts that heterogeneous habitats may provide more niches and diverse ways of exploiting environmental resources, thereby allowing more species to coexist, persist and diversify.2. We aimed to investigate how an edge‐interior gradient related to forest complexity influences species composition, abundance and richness of dung beetles in the western Amazon rainforest. We expected dung beetle abundance and richness to increase along the forest edge‐interior gradient, in accordance with the habitat heterogeneity hypothesis. We also expected strong changes in species composition driven by species turnover in the forest interior and nestedness along the forest edges. We sampled dung beetles using baited pitfall traps across an edge‐interior gradient. We also assessed the variation in forest features along the edge‐interior gradient to identify changes in forest complexity.3. Both species richness and abundance of dung beetles increased along the forest edge‐interior, following the gradient of forest complexity. The Sorensen dissimilarity of dung beetle assemblages was higher among sampling units placed near the forest edge, although neither turnover, nor nestedness was different between the extremes of the forest edge‐interior gradient. There was a clear compositional change along the edge‐interior gradient mostly driven by species turnover. Individual indicator value analysis revealed that species were strongly associated with the forest interior conditions.4. The simplification of the Amazon rainforest near clearings causes compositional changes in dung beetle assemblages. These changes are characterised by species‐poor and low‐abundance assemblages and may impair dung beetle ecological functions and therefore forest recovery.

Dung beetle responses to successional stages in the Amazon rainforest

Amazon rainforest is facing several threats due to anthropogenic activities causing loss of habitat, species, and ecosystem functions. However, several areas are being abandoned after anthropic use allowing secondary succession to occur, which can lead to the passive restoration of community parameters that have been lost. We aimed to investigate the effects of vegetation structure on dung beetle assemblages along a successional gradient in the western Amazon rainforest. Dung beetles were sampled and forest structure variables were measured using standardized protocols along primary, late secondary, and early secondary forests. We used a combination of generalized linear models and multivariate analyses to test for differences in assemblage composition and structure among successional stages and their relationships with vegetation variables. We found that primary forests have different species compositions from both late and early successional forests, with several species strongly associated with primary forests. Dung beetle abundance was higher in primary forests and influenced by variables describing the successional stages (i.e., tree density). Species turnover was the most important β-diversity component among and within each successional stage, with lower values in early secondary forests. Different pathways followed by secondary forests during forest succession may lead to increased species turnover similar to that found in primary forests. Biodiversity conservation will only work if secondary forests are allowed to recover to a late successional stage close to a primary forest stage. The loss of primary forests can cause an irreversible loss of species in need of conservation and with great functional importance in the Amazon rainforest.

Dung Beetles Increase Greenhouse Gas Fluxes from Dung Pats in a North Temperate Grassland.

Soil fauna plays a critical role in various ecosystem processes, but empirical data measuring its impact on greenhouse gas (GHG) emissions from rangelands are limited. We quantified the effects of dung beetles on in situ CO, CH, and NO emissions from simulated cattle dung deposits. Soil in meadows of the semiarid Nebraska Sandhills was treated with three treatments (dung pats with exposure and without exposure to dung beetles, and a no dung control). A closed-chamber method was used to measure GHG fluxes at 0, 1, 2, 3, 7, 10, 14, 21, 28, and 56 d after dung placement in the early season (June-August) and late season (July-September) in 2014 and 2015. The greatest dung beetle abundance was 6 ± 2 beetles per quarter pat on Day 7; the abundance decreased to <2 ± 0.6 on Day 14 and 28 and zero on Day 56. Dung beetles increased fluxes of CO by 0.2 g C d m, NO by 0.4 mg N d m (only in late season 2015), and CH by 0.2 mg C d m. These increases were due to beetle-made macropores that facilitated gas transport in wet dung (initial moisture = 4.6 g g on a dry-weight basis) within 7 d after dung placement. Seasonal environmental differences resulted in greater CO, NO, and CH fluxes in the early season than in the late season. This study concluded that dung beetles increased GHG fluxes from early- and late-season dung deposits on meadows of the semiarid Nebraska Sandhills.

Biodiversity in tropical plantations is influenced by surrounding native vegetation but not yield: A case study with dung beetles in Amazonia

Human-modified forests, including plantations and managed forest, will be a major component of tropical landscapes in the near future. To conserve biodiversity across modified tropical landscapes we must first understand what influences diversity in planted areas. We studied dung beetle communities in Eucalyptus plantations to assess the influence of local (canopy openness and soil texture) and landscape factors (surrounding native forest cover) on taxonomic and functional diversity, and to determine whether biodiversity in plantations is affected by timber production. Dung beetle community composition in Eucalyptus plantations was largely explained by the surrounding native forest cover, as Simpson’s diversity and functional diversity (Rao’s quadratic entropy) increased with the extent of native forest in buffer areas. However, the abundance of dung beetle species associated with native forest was not explained by any of the explanatory variables. The coarse sand content of the soil explained much of the functional similarity between plantations and native forests, as well as variation in dung beetle community structure. The total abundance of dung beetles in plantations increased with coarse sand content, whereas body mass declined, and dung beetle abundance and functional originality decreased with canopy openness. Timber production intensity did not explain the variation in any of the measured diversity parameters. If enhancing biodiversity in plantations is a management goal, then these results highlight the importance of restoring or retaining native forest areas in modified landscapes. They also suggest that integrated management could improve biodiversity in Eucalyptus plantations without reducing timber production.

Dung beetles and nutrient cycling in a dryland environment

Insects are involved in the biogeochemical cycles of multiple elements and influence soil fertility. In particular, soil insects and the functions that they support can affect the response of terrestrial ecosystems to environmental changes. We experimentally studied the role of dung beetles as recyclers of cow dung in drylands of the Central Monte in mid-western Argentina; and we extrapolated these results to ecosystem impact in a grazing field, considering the dung beetle's abundance in summer. We conducted experiments with four species of dung beetles (Sulcophanaeus imperator, Eucranium arachnoides, Digitonthophagus gazella and Malagoniella puncticollis), and quantified their abundance on the field. Dung beetles incorporated nitrogen, ammonium, and phosphorous to the soil, but this activity varied substantially among species. The highest quantity of organic matter, nitrogen and phosphate was incorporated to the soil by S. imperator, one of the larger beetle studied. While the per capita effect of S. imperator is superior to other species studied, the impact on the ecosystem of the invasive D. gazella might be superior due to their major abundance in grazing fields. Our results highlight the importance of considering both components, per capita effect and abundance, to estimate with more reliability the relative importance of dung beetle species. Given that the effect of dung beetles on nutrient cycling is variable among species, and their abundance is variable in space, it is important to conserve beetle diversity in order to maximize their beneficial impacts on soils. Therefore, dung beetle effect on soil might be crucial in drylands to mitigate the nitrogen losses caused by grazing.

Soil Fauna Accelerate Dung Pat Decomposition and Nutrient Cycling into Grassland Soil

Soil fauna play critical roles in various ecosystem functions and services, but empirical data measuring their impact on dung pat decomposition and subsequent nutrient cycling into rangeland soils are limited. The objective of this study was to quantify the effect of soil fauna, using dung beetle as an indicator, on dung decomposition and subsequent translocation of dung nutrients into grassland soil over time. A field experiment was conducted early in the summer season and late in the summer season of 2014 and 2015. In each season, dung beetle abundance, changes in dung properties, and subsequent translocation of dung nutrients into soils were evaluated at 1, 3, 7, 14, 28, and 56 d after placement (DAPs) of exposed dung and nonexposed dung to beetles. Analysis of no-dung control soil was included for comparison. Dung beetles contributed 7% and 4% in the losses of dung moisture and dry matter (DM), respectively; however, dung beetles had no effect on dung pat nutrients. Losses of dung nutrients—42% of water-extractable organic carbon, 46% of water-extractable phosphorus, and 65% of NH4—occurred during the first 14 DAPs. Dung beetles increased soil nutrients in the top 10-cm depth beneath the dung. No effect of beetles was observed in deeper (> 10-cm) soil depth or in soil 30 cm away from the dung. This study concluded that soil fauna, such as dung beetles, accelerated dung moisture and DM losses and subsequent nutrient increase into the top 10 cm of soil.

Seasonality of dung beetles (Coleoptera: Scarabaeinae) in Atlantic Forest sites with different levels of disturbance in southern Brazil

ABSTRACT Dung beetle species were collected between May 2016 and July 2017 with pitfall traps baited with human feces in four Atlantic Forest sites with different levels of disturbance in the state of Rio Grande do Sul, southern Brazil. We sampled 5,535 individuals belonging to 46 species. Canthidium aff. trinodosum (20.71%), Eurysternus parallelus Castelnau, 1840 (14.82%), Onthophagus catharinensis Paulian, 1936 (12.09%), Scybalocanthon nigriceps (Harold, 1868) (7.61 %), Eurysternus caribaeus (Herbst, 1789) (7.49%), and Canthon rutilans cyanescens Harold, 1868 (7.22%) were the most abundant species, which represented 70% of the individuals sampled. Moreno Fortes Biological Reserve had the higher richness and Morro do Cerrito the higher abundance, while Val Feltrina presented the lowest values. The greatest similarity occurred between Turvo State Park and Moreno Fortes Biological Reserve, while Moreno Fortes Biological Reserve and Val Feltrina had the lowest similarity. Only 11 species (23.9%) occurred in all sites, while 14 species were restricted to only one of the fragments. Both abundance and richness of dung beetles were positively correlated with site temperature but not with precipitation.