Dung Beetle Community Structure Research Articles

Response of a dung beetle assemblage along a reforestation gradient in Restinga forest

Scarabaeinae dung beetles are indicator insects used in the evaluation of the ecological effects caused by changes in habitat structure and ecosystem integrity resulting from environmental degradation. We compared dung beetle diversity in conserved restinga forests (coastal tropical moist broadleaf forest) and in reforested areas of various ages during the rainy and dry seasons, on the coast of Paraiba State, Brazil. A total of 3,634 individuals comprising 14 species were collected. In the reforested areas there was a gradual increase in species abundance relative to the area’s age, but in the conserved restinga the abundance of individuals was 10–20 times higher than that recorded in areas of recent reforestation. The highest species richness was found in the conserved restinga and in the oldest reforested area (16 years old) during the rainy season. During the dry season, when environmental conditions do not seem to favor adult survival, most of the species were found in the conserved restinga forest. The dung beetle community structure was related to the increases in habitat heterogeneity in the successional processes of the reforested areas. Our results suggest that reforested areas act as a source of and refuge for dung beetle species.

Dung beetle communities as biological indicators of riparian forest widths in southern Brazil

Riparian forests provide important habitat for many wildlife species and are sensitive to landscape change. Among terrestrial invertebrates, dung beetles have been used to investigate the effects of environmental disturbances on forest structure and diversity. Since many studies demonstrated a negative response of dung beetle communities to increasing forest fragmentation, and that most dung beetle species had a more pronounced occurrence during warmest seasons, three hypotheses were tested: (1) Scarabaeinae richness, abundance, diversity and evenness are lower in thinner riparian zone widths than in wider widths during the warmest seasons; (2) Scarabaeinae richness and abundance are positively influenced by leaf litter coverage and height and canopy cover; and (3) Scarabaeinae composition varies with the reduction in riparian vegetation and among annual seasons. We selected four fragments with different riparian zone widths in three secondary streams in southern Brazil. In each fragment, four sampling periods were carried out seasonally between spring 2010 and winter 2011. We collected dung beetles using pitfall traps with two types of bait. We collected 1289 specimens distributed among 29 species. In spring and summer, dung beetle richness was higher in fragments with the widest riparian zone than in those with a thinner riparian zone, and it did not vary between fragments in fall and winter seasons. Dung beetle abundance did not differ among fragments with different riparian zone widths, but it was higher in spring and summer than fall and winter. Richness and abundance were positively influenced by leaf litter. While dung beetle diversity was higher in fragments with wider riparian zone widths than in those with thinner widths, the evenness was similar among fragments. Dung beetle composition differed between the fragments with the widest and thinnest riparian zones, and it also varied among the seasons. Our results suggest that decreased riparian zones affect negatively to dung beetle community structure in southern Brazil. Fragments with thinner riparian zones had lower beetle richness in warmest seasons and an altered community composition. In this sense, the dung beetles are potentially good indicators of riparian forest fragmentation since some species were indicators of a particular riparian zone width. From a conservation perspective, our results demonstrate that the new Brazilian Forest Code will greatly jeopardize not only the terrestrial and aquatic biodiversity of these ecosystems, but also countless other ecological functions.

Variations in dung beetles assemblages (Coleoptera: Scarabaeidae) within two rain forest habitats in French Guiana

The structure of dung beetle communities inhabiting tropical forests are known to be sensitive to many kinds of environmental changes such as microclimate related to vegetation structure. I examined Scarabaeinae assemblages in two sites of undisturbed high forest and two sites of low forest forming a transitional zone with the open habitat of an inselberg in French Guiana. Sampling was made with pitfall and flight interception traps during 2003 and 2004. The driest and warmest conditions characterized the low forest sites. Across two years we obtained 2 927 individuals from 61 species with pitfall traps and 1 431 individuals from 85 species with flight interception traps. Greater species richness and abundance characterized all sites sampled with pitfall traps during 2003 more than 2004. In 2003 no differences were detected among sites by rarefaction analyses. In 2004 the species richest high forest site was significantly different from one of the low forest sites. For both years Clench model asymptotes for species richness were greater in high forest than in low forest sites. For both years, mean per-trap species richness, abundance and biomass among high forest sites were similar and higher than in low forest sites, especially where the lowest humidity and the highest temperature were recorded. Within the two low forest sites, species richness and abundance recorded during the second year, decreased with distance to edge. Different dominant roller species characterized the pitfall samples in one site of low forest and in other sites. Small variations in microclimatic conditions correlated to canopy height and openness likely affected dung beetle assemblages but soil depth and the presence of large mammals providing dung resource may also play a significant role.

Influences of Different Large Mammalian Fauna on Dung Beetle Diversity in Beech Forests

This paper focuses on biological relationships between mammalian species richness and the community structure of dung beetles in cool-temperate forests in the northernmost part of mainland Japan. The composition of beetle assemblages was evaluated at 3 sites in undisturbed beech forests with different mammalian fauna. In spring and summer 2009, beetles were collected at each site using pitfall traps baited with feces from Japanese macaques, Macaca fuscata Blyth (Primates: Cercopithecidae); Asiatic black bears, Ursus thibetanus Cuvier (Carnivora: Ursidae); Japanese serows, Capricornis crispus Temminck (Artiodactyla: Bovidae); and cattle. In the present study, 1,862 dung beetles representing 14 species were collected, and most dung beetles possessed the ecological characteristic of selecting specific mammalian feces. The present findings indicated that although species diversity in dung beetle assemblages was not necessarily positively correlated with mammalian species richness in cool-temperate forests, the absence of the macaque population directly resulted in the marked reduction of the beetle abundance, with the loss of the most frequent species, Aphodius eccoptus Bates (Coleoptera: Scarabaeidae) during spring.

Diversity and community structure of dung beetles (Coleoptera: Scarabaeinae) associated with semi-urban fragmented agricultural land in the Malabar coast in southern India

An evaluation of the diversity and community structure of dung beetles associated with semiurban agricultural land in the Malabar coast of southern India revealed that urbanization has led to decreased diversity compared to regional forests, and has affected the community status of dung beetles. However, contrary to expectations, species richness was observed to be equivalent to rural agricultural fields in the region. Low abundance of prominent agricultural habitat species indicates that the study area has changed as a result of habitat modification/urbanization, and the prevailing conditions are not ideal for the establishment of the most common species in agriculture belts. Prominence of two less common species, Tiniocellus spinipes and Caccobius vulcanus, indicates these generalist urban adaptable (synanthropic) species have become increasingly widespread and locally abundant. The low abundance of tunnelers and rollers is attributed to fragmentation of the urban agricultural belt, low mammalian diversity and dung availability, and the hard nature of the laterite soil in the Malabar coast region.

Using dung beetles to evaluate the effects of urbanization on Atlantic Forest biodiversity

We used dung beetles to evaluate the impact of urbanization on insect biodiversity in three Atlantic Forest fragments in Londrina, Paraná, Brazil. This study provides the first empirical evidence of the impact of urbanization on richness, abundance, composition and guild structure of dung beetle communities from the Brazilian Atlantic Forest. We evaluated the community aspects (abundance, richness, composition and food guilds) of dung beetles in fragments with different degrees of immersion in the urban matrix using pitfall traps with four alternative baits (rotten meat, rotten fish, pig dung and decaying banana). A total of 1 719 individuals were collected, belonging to 29 species from 11 genera and six Scarabaeinae tribes. The most urban-immersed fragment showed a higher species dominance and the beetle community captured on dung presented the greatest evenness. The beetle communities were distinct with respect to the fragments and feeding habits. Except for the dung beetle assemblage in the most urbanized forest fragment, all others exhibited contrasting differences in species composition attracted to each bait type. Our results clearly show that the degree of urbanization affects Atlantic Forest dung beetle communities and that the preservation of forest fragments inside the cities, even small ones, can provide refuges for Scarabaeinae.

Habitat fragmentation alters the structure of dung beetle communities in the Atlantic Forest

Habitat loss and fragmentation have turned into the most important threats to biodiversity and ecosystem function worldwide. Here we investigate the effects of habitat fragmentation and drastic changes in tree communities on dung beetle richness and community structure. This study was carried out in a severely fragmented 670-km 2 forest landscape of the Atlantic Forest of north-eastern Brazil. Sampling was carried out in 19 forest fragments between September 2007 and March 2008 with the use of pitfall traps and flight interception traps. A total of 5893 individuals and 30 species of dung beetle were collected. Fragment area and isolation were the most significant explanatory variables for predictable and conspicuous changes in dung beetle species richness. Smaller and isolated fragments presented lower number of species, but fragments with lower tree species richness and lower proportion of shade-tolerant species were also considerably impoverished in terms of dung beetle species richness. The body mass of dung beetles were explained by fragment area and the percentage of emergent trees with smaller and less stratified fragments being dominated by small-bodied dung beetles. An ordination analysis segregated dung beetle communities between small fragments (<100 ha) and the control area. Seventy-seven percent of the species were recorded in the control area and 22% of all species were unique to this habitat. Our findings indicate that large fragments in the Atlantic Forest appear to consist in a sort of irreplaceable habitats for particular groups of dung beetle species, as well as for the integrity of their communities.

Community structure of dung beetles in Amazonian savannas: role of fire disturbance, vegetation and landscape structure

Understanding the relative influence of environmental and spatial variables in driving variation in species diversity and composition is an important and growing area of ecological research. We examined how fire, local vegetation structure and landscape configuration interact to influence dung beetle communities in Amazonian savannas, using both hierarchical partitioning and variance partitioning techniques to quantify independent effects. We captured a total of 3,334 dung beetles from 15 species at 22 savanna plots in 2003. The species accumulation curve was close to reaching an asymptote at a regional scale, but curves were variable at the plot level where total abundance ranged from 17 to 410 individuals. Most plots were dominated by just three species that accounted for 87.7% of all individuals sampled. Hierarchical partitioning revealed the strong independent and positive effect of percentage forest cover in the surrounding landscape on total dung beetle abundance and species richness, and richness of uncommon species and the tunneler guild. Forest cover also had a negative effect on community evenness. None of the variables that related to fire affected community metrics. The minimal direct influence of fire was supported by variance partitioning: partialling out the influence of spatial position and vegetation removed all of the individual explanation attributable to fire, whereas 8% of the variance was explained by vegetation and 28% was explained by spatial variables (when partialling out effects of the other two variables). Space-fire and vegetation-fire joint effects explained 14 and 10% of the dung beetle community variability, respectively. These results suggest that much of the variation in dung beetle assemblages in savannas can be attributed to the spatial location of sites, forest cover (which increased the occurrence of uncommon species), and the indirect effects of fires on vegetation (that was also dependent on spatial location). Our study also highlights the utility of partitioning techniques for examining the importance of environment variables such as fire that can be strongly influenced by spatial location.

Diversity and community structure of dung beetles (Coleoptera: Scarabaeidae) across a habitat disturbance gradient in Lore Lindu National Park, Central Sulawesi

Shahabuddin (2010) Diversity and community structure of dung beetles (Coleoptera: Scarabaeidae) across habitat disturbance gradient in Lore Lindu National Park, Central Sulawesi. Biodiversitas 11: 29-33. Dung beetles are important component of most terrestrial ecosystems and used to assess the effects of habitat disturbance and deforestation. This study aimed at comparing dung beetle assemblages among several habitat types ranging from natural tropical forest and agroforestry systems to open cultivated areas at the margin of Lore Lindu National Park (LLNP), Central Sulawesi (one of Indonesia’s biodiversity hotspots). Therefore, 10 pitfall traps baited with cattle dung were exposed at each habitat type (n = 4 replicate sites per habitat type) to collect the dung beetles. The resultsshowed that species richness of dung beetles declined significantly from natural forest to open area. However cacao agroforestry systems seemed to be capable of maintaining a high portion of dung beetle species inhabiting at forest sites. The closer relationship between dung beetle assemblages recorded at forest and agroforestry sites reflects the high similarity of some measured habitat parameters (e.g. vegetation structure and microclimate) between both habitat types, while species assemblages at open areas differedsignificantly from both other habitat groups. These results indicated that habitat type has importance effect on determining the species richness and community structure of dung beetles at the margin of LLNP.Key words: forest conversion, diversity, habitat selection, dung beetles marker.

Escarabajos coprófagos (Coleoptera: Scarabaeinae) de la vertiente voroccidental, Sierra Nevada de Santa Marta, Colombia

The community structure of dung beetles in the middle and lower river basin of the Gaira river, Sierra Nevada de Santa Marta, Colombia, is described. Four sites were selected along an altitudinal gradient of 50-940 m for sampling from June to October, 2004. Dung beetles were captured using modified pitfall traps and manual recollections. We captured 7,872 individuals belonging to 29 species, distributed in 15 genera and five tribes of Scarabaeinae. Canthon and Onthophagus were the most diverse genera, each represented by six species. The sampled sites shared the following species: Onthophagus acuminatus Harold, O. clypeatus Blanchard, O. marginicollis Harold. Bocatoma was the most diverse site with 23 species; whereas Port Mosquito presented the highest abundance, with 3,262 individuals. Seven species represented 89% of all captures: Canthidium sp., Dichotomius sp., Uroxys sp. 1, Uroxys sp. 2, O. marginicollis, O. clypeatus and O. acuminatus. Of the 29 captured species, 17 belonged to the functional group of diggers and 10 were ball-rollers. We did not observe significant among-site differences in community structure. Abiotic factors such as altitude, temperature and humidity cannot explain observed variation in community structure across sites, indicating other variables such as vegetation cover, density of the vegetation and soil type may play a role in the community structure of these insects.

Utilisation of introduced Brazilian pastures ecosystems by native dung beetles: diversity patterns and resource use

Abstract. Cattle pastures dominated by introduced grasses are a characteristic component of many tropical landscapes in Brazil, yet little information is available concerning the insect communities that inhabit these novel ecosystems. Dung beetles are a conspicuous element of pasture insect communities, and make a significant contribution to dung decomposition, parasitic fly control, and soil bioturbation. We sampled dung beetle assemblages in twelve introduced pastures near Viçosa, Minas Gerais, Brazil. We used pitfall traps baited separately with cow and horse dung, and collected a total of 456 dung beetles, comprising 23 species from 13 different genera. We analysed patterns of alpha and beta diversity, community structure, and species composition among pastures and bait types. Cow dung harboured significantly more species, but a similar abundance of dung beetles compared with horse dung. However, both dung types supported species exclusive to that type, and hosted a distinct dung beetle community structure and composition. Although livestock (cattle and horses) was introduced to Brazil less than 500 years ago, our data suggest that novel and well‐structured dung beetle communities are actively exploiting these novel food resources in Brazilian pasturelands.

Temporal shifts in dung beetle community structure within a protected area of tropical wet forest: a 35‐year study and its implications for long‐term conservation

Summary Throughout much of the tropics, habitat loss is increasing and intensifying on the unprotected land surrounding conservation areas. The influence of these land‐use changes on biodiversity is poorly understood. This study used data on dung beetles, a taxonomic group widely acknowledged to be an effective ecological indicator of anthropogenic disturbance, to evaluate temporal changes in diversity inside a natural protected area. Using data from quantitative sampling events over the last 35 years along with an exhaustive review of the information available in museums and the literature, we present evidence suggesting that the dung beetles community structure has shifted dramatically over time at La Selva Biological Station, Costa Rica. To date, 50 dung beetle species have been reported from La Selva. Of these, 10 (20%) were consistently collected within the study timeframe while 21 species (42%) were uncommon. Our results indicate a tendency toward decreasing species richness and changes in species composition over time. Analysis of the community structure revealed a decrease in diversity (H′), an increase in dominance (D) and a decrease in evenness (J) over the 35‐year period; all of which can be linked to an increase in the dominance of one species (Onthophagus acuminatus). These changes were also reflected in the proportional abundance of major species guilds. Synthesis and applications. Despite the relatively low human impact within La Selva, this study suggests that the dung beetle community has changed as result of habitat loss in the surrounding landscape and the progressive increasing isolation of the reserve over the last 35 years. Our findings, together with studies of other biota in the reserve, indicate a worrying decline in the conservation value of La Selva in recent decades. This shift in the diversity and composition of native forest biota needs to be taken into account in future studies that continue to rely on La Selva as providing an intact baseline for comparative research. More importantly, we suggest that the size of the reserve may need to be increased if its ecological integrity is to be restored. This study provides further evidence that isolated protected areas may often fail to safeguard biodiversity in the long term, and that to be viable, conservation strategies urgently need to adopt a wider landscape perspective.

Species Composition and Community Structure of Dung Beetles Attracted to Dung of Gaur and Elephant in the Moist Forests of South Western Ghats

The community structure of dung beetles attracted to dung of gaur, Bos gaurus (H. Smith) (Artiodactyla: Bovidae) and Asian elephant, Elephas maximus Linnaeus (Proboscidea: Elephantidae), is reported from the moist forests of Western Ghats, in South India. The dominance of dwellers over rollers, presence of many endemic species, predominance of regional species and higher incidence of the old world roller, Ochicanthon laetum, make the dung beetle community in the moist forests of the region unusual. The dominance of dwellers and the lower presence of rollers make the functional guild structure of the dung beetle community of the region different from assemblages in the moist forests of south East Asia and Neotropics, and more similar to the community found in Ivory Coast forests. The ability of taxonomic diversity indices to relate variation in dung physical quality with phylogenetic structure of dung beetle assemblage is highlighted. Comparatively higher taxonomic diversity and evenness of dung beetle assemblage attracted to elephant dung rather than to gaur dung is attributed to the heterogeneous nature of elephant dung. Further analyses of community structure of dung beetles across the moist forests of Western Ghats are needed to ascertain whether the abundance of dwellers is a regional pattern specific to the transitional Wayanad forests of south Western Ghats.

Assessing sustainability indicators for tropical forests: Spatio-temporal heterogeneity, logging intensity, and dung beetle communities

Sustainable management of tropical forests has been identified as one of the main objectives for conservation of global biodiversity and management of carbon stocks. To achieve this goal, managers need tools to assess the sustainability of current management practices. Several international initiatives have undertaken the development of sets of criteria and indicators to help managers move towards sustainability. Among the indicators considered, the structure and composition of dung beetle communities have been identified as excellent indicators of ecological sustainability. However, as occurs with most indicators of the ecological sustainability of forest management, dung beetle surveys require intensive field work making their application over large areas expensive, time consuming, and logistically challenging. A need for prioritization is evident. This work presents a novel approach to the assessment of the Center for International Forestry Research (CIFOR) ecological sustainability indicator I.2.1.2: “The change in diversity of habitats as a result of human interventions is maintained within critical limits as defined by natural variation and/or regional conservation objectives”. Using variography of vegetation index data derived from remotely sensed imagery, we show (1) how the differences in forest structural heterogeneity observed between forest management units and natural areas can be used to identify priority areas for field survey of ecological sustainability indicators (hereafter “priority-for-survey”) and (2) how these priorities correspond to dung beetle community structure and composition. Links between temporal change in forest structural heterogeneity, logging intensity, and dung beetle community structure and composition were established by means of correlation analysis and matrix regression modeling. We found that areas ranked as low priority-for-survey based on image analysis showed no significant difference in dung beetle species richness or diversity from natural reference areas. Further, we found significantly higher dung beetle species richness and diversity estimates in areas ranked as moderate or moderate-low priority-for-survey over the low and reference areas. Finally, the dung beetle community composition in the high priority-for-survey category was significantly less rich and less diverse than any other category. We identified a logging intensity threshold of four trees per hectare as a transition to significant differences in forest structural heterogeneity and the richness and diversity of associated dung beetle communities.

Effects of fluazuron and ivermectin treatment of cattle on the structure of dung beetle communities

Abstract A long-term and large-scale field study was carried out to assess the ecotoxicological effect on the dung beetle fauna of cattle treatment with ivermectin (broad-spectrum endectocide) and fluazuron (acaricide) under normal extensive farming conditions in South Africa. One herd of 25 heifers was treated four times at an 8-week interval (starting late November 2001) with a standard injection of ivermectin (200 μg/kg) and a standard pour-on dosage of fluazuron (3 mg/kg) and another herd was left untreated as a control. This set-up was replicated on a second, separate farm and the four herds were kept in four separate paddocks of about 80 ha each. Dung beetle communities were monitored over an entire farming season, from early November 2001 until August 2002. This study was carried out in a very moist year with above average rainfall. The impact of the treatment on the dung beetle communities was examined using a variety of community measures as well as a wide range of univariate, graphical and multivariate analyses. There was no observable effect of the administered drugs on the dung beetle communities. Species richness and diversity seemed unaffected in the treated communities and the ecological similarity of the treated and control communities remained high through most of the trial. These results support the notion that the ecotoxicological impact of antiparasitic drugs depends on factors such as climatic conditions, spatial scale of treatment and proportion of animals treated.

Does Reduced-Impact Logging Help Preserve Biodiversity in Tropical Rainforests? A Case Study from Borneo using Dung Beetles (Coleoptera: Scarabaeoidea) as Indicators

The role of reduced-impact logging on the preservation of biodiversity in tropical lowland dipterocarp rainforest is examined by looking at differences in dung beetle community structure between two sites logged in 1993: one harvested using reduced-impact methods and one using conventional techniques. Collections were made using two flight intercept traps over 7 d, and samples were compared with previous collections made from primary forest (riverine and interior-forest) and older forest logged using conventional techniques (logged in 1981). Of the two 1993 sites, the higher diversity and species richness (S = 57, n = 969, alpha = 13.23, H′ = 3.24) was recorded in the forest logged using reduced-impact techniques: the conventionally logged site had both lower diversity and species richness (S = 48, n = 1968, alpha = 8.88, H′ = 1.89), and lacked some primary forest specialists present in the reduced-impact forest samples. The dung beetle community in the 1993 conventional logged site is similar to that of the conventional logging site harvested in 1981. Primary forest has a well-defined ecotone, from interior to riverine forest: both 1993 sites contain a mixture of interior-forest and riverine specialists that are usually spatially separated along this ecotone. Although the dung beetle assemblage in the forest harvested by reduced-impact logging is more similar to a primary interior-forest assemblage than the conventionally logged site, both 1993 sites have assemblages that are closer in similarity to assemblages from primary-riverine habitat than they are to ones from primary interior-forest. However, because the forest logged using reduced-impact logging techniques has a more equitable and diverse dung beetle assemblage and a greater number of interior-forest specialists than the conventionally logged site, this study suggests that reduced-impact logging has better preserved the primary forest assemblage than conventional logging techniques.