Dung Piles Research Articles

Concentrations of faecal glucocorticoid metabolites in Asian elephant's dung are stable for up to 8 h in a tropical environment.

The use of faecal glucocorticoid metabolites (fGCMs) has facilitated the development of non-invasive methods to study physiological conditions of endangered wildlife populations. One limitation is that fGCM concentrations are known to change over time and to vary according to different environmental conditions. The aim of this study was to perform a controlled dung decay experiment to understand the impact of time (since defecation) and two common environmental variables (exposure to water and direct sunlight) on fGCM concentrations of Asian elephants (Elephas maximus). Eighty dung piles from 10 Malaysian elephants were randomly exposed to a 2×2 combination of treatments (wet-shade, dry-shade, wet-sun and dry-sun) and repeatedly subsampled from the time of defecation through to 2 days post-defecation (n=685 faecal subsamples). Overall, the mean concentration of fGCMs was stable in samples of up to 8h old from defecation time, regardless of environmental treatment (water or direct sunlight); thereafter, the overall mean fGCM concentrations increased, peaking 1 day after defecation (31.8% higher than at defecation time), and subsequently decreased (reaching values 9.2% below defecation time on the second day). Overall, the treatment of sun exposure resulted in higher fGCM concentration compared with shade, whereas water exposure (compared with no water exposure) had no impact on fGCM concentrations. Hence, in field studies we recommend collecting dung samples <8h old and recording shade conditions (e.g. sun vs. shade) as a covariate for the subsequent interpretation of fGCM measurements. This study has helped to identify the optimal window for sampling in which we can have a higher confidence in interpreting the results as being a genuine reflection of glucocorticoid status in the elephant.

How much Dillenia indica seed predation occurs from Asian elephant dung?

Elephants are thought to be effective seed dispersers, but research on whether elephant dung effectively protects seeds from seed predation is lacking. Quantifying rates of seed predation from elephant dung will facilitate comparisons between elephants and alternative dispersers, helping us understand the functional role of megaherbivores in ecosystems. We conducted an experiment to quantify the predation of Dillenia indica seeds from elephant dung in Buxa Reserve, India from December 2012 to April 2013. Using dung boluses from the same dung pile, we compared the number of seeds in boluses that are a) opened immediately upon detection (control boluses), b) made available only to small seed predators (<3 mm wide) for 1–4 months, and c) made available to all seed predators and secondary dispersers for 1–4 months. Using a model built on this experiment, we estimated that seed predation by small seed predators (most likely ants and termites) destroys between 82.9% and 96.4% of seeds in elephant dung between the time of defecation and the median germination date for D. indica. Exposure to larger seed predators and secondary dispersers did not lead to a significant additional reduction in the number of seeds per dung bolus. Our findings suggest that post-dispersal seed predation by small insects (<3 mm) substantially reduces but does not eliminate the success of elephants as dispersers of D. indica in a tropical moist forest habitat.

Seed Dispersal Potential of Asian Elephants (Elephas maximus) in Kumaragala Forest Reserve, Matale District, Sri Lanka

Elephant foraging directly affects the growth, survival and vegetation dynamics of forests. They consume a variety of plants including trees, vines, shrubs and herbs. Even though elephants are considered as important seed dispersal agents, very few studies have been carried out to study the seed dispersal ability of elephants in Sri Lanka. Hence, this study was conducted in a natural forest and a bordering chena cultivation area in Maragamuwa (70070‟N and 80065‟E), within Kumaragala Forest Reserve, from September 2014 to February 2015 to determine the seed dispersal capability of elephants. Three boli were collected randomly from each dung pile and rest were kept in the field and observed until the decomposition was complete. Collected boli were broken and visible seeds were identified by comparing with a reference seed collection. Unidentified seeds were cultivated in sterilised soil. Broken boli were kept in a greenhouse and watered to identify the plants whose seeds were invisible to the naked eye. The study found a total of 84 dung piles and 252 boli were collected from those piles. Fifty three piles out of 84 (63.09%) contained seeds or seedlings of one or more plant species. A total of 22 plant species belonging to nine families were observed to germinate from boli. Among these 22 species, 12 species were cultivated (representing 54.55% of the plant species germinated from boli) and 10 (45.45%) were non-cultivated plant species. Seventeen plant species from chena cultivation area and six species from natural forest were found. Careya arborea and Megathyrsus maximus were the most frequently found seeds and seedlings. Among the cultivated plants, climbers (41.67%), shrubs (8.33%), and herbs (50%) were found, and among the non-cultivated plants trees (60.00%), herbs (4.55%) and shrubs (13.64%) were found regularly. It is interesting to note that herbs formed 50% of the cultivated plants, while they formed only 4.55% of the non-cultivated plants germinating from elephant dung boli. The results from this study could be used to develop habitat enrichment programs for wild elephants that help in mitigating the human-elephant conflict, which is now becoming a serious conservation issue for the Sri Lankan elephant. Keywords: Mega-herbivores, Foraging, Elephant dung, Human-elephant conflict, Conservation

中国农业昆虫生态调节服务价值的初步估算

PDF HTML阅读 XML下载 导出引用 引用提醒 中国农业昆虫生态调节服务价值估算 DOI: 10.5846/stxb201308242147 作者: 作者单位: 中国科学院动物研究所 农业虫害鼠害综合治理研究国家重点实验室 北京,中国科学院动物研究所 农业虫害鼠害综合治理研究国家重点实验室 北京,山东农业科学院 植物保护研究所 济南,中国农业大学 植物保护学院 北京,江西农业大学林学院,山东省植物保护总站,中国科学院动物研究所 农业虫害鼠害综合治理研究国家重点实验室 北京 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金委项目(31200321); 环保部专项(STSN-04-04) The economic value of ecological regulating services provided by agricultural insects in China Author: Affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents，Institute of Zoology, Chinese Academy of Sciences,State Key Laboratory of Integrated Management of Pest Insects and Rodents，Institute of Zoology, Chinese Academy of Sciences,Institute of Plant Protection,Shandong Academy of Agricultural Sciences,Jinan,People’s Republic of China,State Key Laboratory of Integrated Management of Pest Insects and Rodents，Institute of Zoology, Chinese Academy of Sciences,,The plant protection station of Shandong provience,State Key Laboratory of Integrated Management of Pest Insects and Rodents，Institute of Zoology, Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:昆虫是生物多样性最丰富的物种类群,其在维持生态系统功能,维系并保持着自然界的生态平衡,满足人类需求中的具有重要作用。讨论了昆虫生态服务价值的定量估算方法,基于2007年统计数据,计算了我国农牧业生产中昆虫传粉功能、天敌昆虫控害功能和分解作用的服务价值。结果表明,昆虫在我国农业生产中传粉服务价值为6790.30×108 元,占其当年农作物生产总经济价值的54.05%;天敌昆虫的控害服务价值为2621.00×108 元,占其当年重要作物总经济价值的9.09%;分解昆虫(甲虫)对牧场牛羊排泄物的分解作用的价值远超过90.84×108 元。由此估计出了我国2007年农业昆虫生态调节服务总价值超过9502.14×108 元,相当于当年国内生产总值GDP的3.7%。显示昆虫所产生的生态调节服务价值,与我国森林或草地生态系统的直接和间接服务价值处于同一数量级,同样具有巨大的经济价值。为保护与利用昆虫生物多样性,发挥其生态服务功能奠定了基础。 Abstract:Society has recognized the value of ecosystem services. Insects are one of the most diverse groups, playing a significant role in maintaining ecosystem function and ecological balance, and fulfilling human demands. Insect ecological services are the functional roles in ecosystem processes, benefiting humans with goods and services such as pollination, pest control and decomposition. Insect ecological services include provisioning, regulation, cultural and support services. The economic value of insect ecological services can be divided into direct-, indirect-, option- and existence values. The ecological regulating services of insects involve pollination, biological control and dung burial. Insects perform pollination services to crops, vegetables and fruits which are an important ecological service. Pollination is usually the transfer of pollen from the male sex organ to the receptive portion of the female sex organ in flowering plants. Insect pollinators are adapted to many flowering plant species and are provided with primary rewards that attract (i.e., "attract and reward") and establish pollen vectors returning to flowers. Rewards include nectar, pollen, lipid secretions, food bodies, scents, resins, and material for nest building. Biological control is a particular type of pest control, resulting in predatory/parasitoid insects suppressing pest densities to relatively low levels. This type of ecologically based pest management infers that the "natural enemies" control the pest species. The types of natural enemies used for biological control vary depending on the type of pest. The decomposition of organic matter and the recycling of carbon are provided by beetles that bury dung. Dung beetles process a substantial amount of the animal dung that has accumulated in ecosystem. Dung beetles are medium to large-sized beetles specializing in feeding and breeding on an ephemeral and discrete food resource, consisting mainly of the dung piles produced by herbivorous warm-blooded animals. The dung beetles provide regulating services that reduce forage fouling, nitrogen volatilization, parasites and pest flies. Humans could not persist without these insect provided services. Estimating the value of ecological services provided by insects may help establish a higher priority for their conservation. This paper discusses the concept and categorization of insect ecosystem services, including an economic evaluation of those services. In 2007, insect pollination, pest control and dung burial values were estimated using agricultural production data from China. The results indicated that the insect regulating service value for pollination was 6790.30×108 yuan RMB, accounting for up to 54.05% of the total value of pollinator serviced crops. The value of pest control from natural enemies was 2621.00×108 yuan RMB, which was up to 9.09% of the total value of the crops serviced. The value of dung burial was 90.84×108 yuan RMB. The total insect regulating service was valued at 9502.14×108 yuan RMB, accounting for up to 3.7% of China's GDP (2007). These results show the annual value of insect regulating service in an agroecosystem are similar to the economic values of grassland or forest ecosystem services in China. The accurate valuation of insect ecological services is critical to establishing and preserving the ongoing development of insect-based resources and biodiversity in China. 参考文献 相似文献 引证文献

Studies on feeding behaviour and daily activities ofRhinoceros unicornisin natural and captive condition of Assam

The present study was conducted on feeding behaviour and daily activities of rhinoceros (Rhinoceros unicornis) in natural (Pobitora Wildlife Sanctuary, Assam) and captive (Assam state zoo, Guwahati) condition. The observations were made in both day and night time. The study revealed that the rhinoceros spent maximum time in grazing both on grassland (30.14 per cent) and wetland (21.73 per cent). They were observed to be top grazer and preferred to graze slowly in grassland. Early morning and afternoon were most suitable time for grazing for them. Wallowing, galloping, easy walking, standing, resting, and sleeping were some other myriad behaviour that can be seen while watching the rhino in day and night time in natural condition. In comparison to the natural condition, the rhino in the captive condition wallowed for less time (6 per cent) and sleeping (50 per cent) was primary activities of rhinos in the night time. It was observed that rhino maintained good relation with other animals during grazing in both natural and captive condition. Season had effect on the behaviour of rhino specially on grazing and wallowingwhere theanimals spent more time in grazing during post monsoon season than the pre monsoon, monsoon and winter seasons. Highest per cent of wallowing was in the monsoon season (46%) as compared to the pre monsoon (14%). Rhinos had tendency to defecate in a particular place for a long time making a huge dung pile both in natural and captive conditions.

The effect of small-scale land use on vegetation in the Valdivian Coastal Range (Chile)

Today, native vegetation in the Valdivian Coastal Range (VCR) is restricted to areas where small-scale land use dominates resulting in a vegetation mosaic. This study (1) provides a description of the vegetation types (VT) within the vegetation mosaic, (2) identifies land use drivers that lead to either degradation or recovery processes and, (3) attempts to provide an explanation for the vegetation mosaic with a conceptual model. In two regions of the VCR we sampled 102 plots for composition of vegetation and indicators of livestock browsing, timber cutting and coppice forestry. We classified the vegetation using a flexible beta method and Bray-Curtis distance. Diagnostic species were identified by an extended indicator species analysis. The clustering results were visualized in NMDS and recursive partitioning was used to explain variations in the VTs as a function of the land use variables. Differentiating effects were tested using PERMANOVA and a conceptual model for the vegetation dynamics was developed from the results. Four VTs such as (1) extensively grazed non-native grasslands (EGN); (2), closed and semi-closed grazed Ugni and Berberis shrublands; (3) severely impacted evergreen forests; and (4) sparsely disturbed evergreen forests were recognized. The browsing indicators were important for differentiating the VTs. The EGN grasslands were differentiated by having more than 0.075 dung piles/m². Areas with fewer dung piles but direct browsing effects had the greatest impact on vegetation. Forests were preserved when the mean browsing index was equal to or lower than 0.5. The cutting frequency was significant in determining overall floristic composition. We showed that shrublands and evergreen forests within the vegetation mosaic and the result of small-scale farming led to high native forest species richness. This makes the vegetation mosaic especially valuable in a landscape dominated by exotic tree monocultures.

Spatial Pattern of Pindó Palm (Syagrus romanzoffiana) Recruitment in Argentinian Atlantic Forest: The Importance of Tapir and Effects of Defaunation

AbstractHunting pressure, fragmentation and deforestation have caused global declines in animal abundance, and the consequences for plant communities are poorly understood. Many large‐seeded plants, for instance, depend on large and endangered vertebrates for seed dispersal. In some Semi‐deciduous Atlantic Forests, endangered tapirs (Tapirus terrestris) are major dispersers of pindó palms (Syagrus romanzoffiana). Here, we compare recruitment patterns of pindó palms between protected and disturbed (defaunated) Atlantic Forest areas in Argentina and evaluate the potential consequences of the lack of the main disperser for pindó palm regeneration. We analyzed the number and spatial pattern of pindó adults, offspring, and tapir dung piles within ten plots established in an area spanning tapir latrines inside Iguazú National Park and in a fragmented forest area outside the park where tapir is locally extinct. In both areas, we evaluated recruitment levels beneath 24 adult palms in circular plots centered on adult stems. We found lower pindó palm recruitment outside the park where offspring tended to be aggregated around adult palms. In contrast, in Iguazú National Park offspring were spatially associated with tapir dung‐piles, in which most offspring were registered. Recruitment under adults was higher outside the park suggesting a lower rate of seed removal in disturbed areas. Our results show that tapir dispersal promotes higher recruitment levels of pindó offspring and shapes their spatial pattern, breaking the spatial association with adult (presumably maternal) palms. These results are useful for predicting the impact of local tapir extinction on this palm.

Differences between beetle communities colonizing cattle and horse dung

Piles of fresh cow and horse dung were placed in a pasture in Dziarny in north-east Poland. The differences between the beetle communities colonizing both types of dung at various stages of succession were analyzed. Beetles were sampled 2, 5, 10, 15, 20 and 25 days after placing the piles of dung in the pasture. A total of 5 343 individuals belonging to 125 species and 10 families were collected in 24 samples. None of the species of beetles collected colonized exclusively one type of dung. Several taxa showed a clear preference for cow or horse dung. Beetle succession proceeded faster in horse dung and there were significant differences in the dominant species recorded in the two types of dung. The reasons for the reported patterns are discussed.

Distribution and genetic diversity of the Endangered Abbott’s duiker Cephalophus spadix in the Udzungwa Mountains, Tanzania

Abbott's duiker Cephalophus spadix is a forest antelope endemic to a very few high- land forests in Tanzania. Apparently extinct over much of its historical range, the species is listed as Endangered by the International Union for Conservation of Nature based on its rarity and its known current distribution in only 5 isolated upland areas: Kilimanjaro, Southern Highlands, West Usambara, Rubeho and Udzungwa Mountains. In contrast to the situation in the rest of its range, Abbott's duiker is relatively well documented and locally abundant in parts of the Udzungwa Mountains, which may now be the only stronghold for the species. We review the distribution of Abbott's duiker within the Udzungwa Mountains and present new information based on the non- invasive genetic identification of dung piles collected from the majority of forest blocks between 2006 and 2010 (73 confirmed dung samples). Our results include new records from outlying forest blocks where the presence of Abbott's duiker was previously unknown. Moreover, we present the first population-level analysis of genetic structure and diversity in this endangered species based on nuclear microsatellites and mitochondrial sequence data. While these genetic results are lim- ited due to small sample sizes, they indicate differentiation from other Abbott's duiker popula- tions, as well as low genetic diversity relative to sympatric antelope species. Finally, we discuss threats to Abbott's duiker and identify broad trends within the differently managed Udzungwa Mountain forests, and elsewhere, that suggest potentially successful conservation strategies for this neglected species.

Effects of logging road networks on the ecological functions of dung beetles in Peninsular Malaysia

The loss of forest biodiversity via anthropogenic disturbance is severe in tropical countries and its consequences to ecological functions are of global concern. Selective logging is one of the main causes of tropical forest degradation, and its ecological impacts often result from the construction of road networks such as skid trails, logging roads and log yards. However, the effects of such narrow road clearings on forest-dependent species and associated ecological functions have rarely been studied. The present study therefore aimed to assess the impacts of such clearings on dung burial and secondary seed dispersal by dung beetles. The abundance of all functional guilds and the total biomass of dung beetles were drastically low at road clearings, but guild composition was only significantly different between the forest interior and log yards. Dung burial rates decreased with canopy openness, where 40% of dung remained unburied at logging roads and log yards. However, beads (seed mimics) in the dung piles were buried deeper and more frequently in log yards than the forest interior. In contrast, horizontal seed-removal distance was longer in the forest interior than at all road clearing sites. Reduced dung burial rates, and deeper but shorter, seed removal in clearings implies a negative effect of road clearings on the efficiency of secondary seed dispersal and other ecological functions of dung beetles. The imposition of limits on the number and size of logging road networks would be effective for retaining the ecological functions performed by the diverse forest-dependent species after logging.

The influence of feral horses dung piles on surrounding vegetation

Fil: Zalba, Sergio Martin. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina

Diurnal dung beetles use the intensity gradient and the polarization pattern of the sky for orientation.

To escape competition at the dung pile, a ball-rolling dung beetle forms a piece of dung into a ball and rolls it away. To ensure their efficient escape from the dung pile, beetles rely on a 'celestial compass' to move along a straight path. Here, we analyzed the reliability of different skylight cues for this compass and found that dung beetles rely not only on the sun but also on the skylight polarization pattern. Moreover, we show the first evidence of an insect using the celestial light-intensity gradient for orientation. Using a polarizer, we manipulated skylight so that the polarization pattern appeared to turn by 90 deg. The beetles then changed their bearing close to the expected 90 deg. This behavior was abolished if the sun was visible to the beetle, suggesting that polarized light is hierarchically subordinate to the sun. When the sky was depolarized and the sun was invisible, the beetles could still move along straight paths. Therefore, we analyzed the use of the celestial light-intensity gradient for orientation. Artificial rotation of the intensity pattern by 180 deg caused beetles to orient in the opposite direction. This light-intensity cue was also found to be subordinate to the sun and could play a role in disambiguating the polarization signal, especially at low sun elevations.

Frugivory and seed dispersal by the Asian Elephant Elephas maximus in the tropical forests of Nilgiri Biosphere Reserve, southern India

Seed dispersal plays a potential role in plant species demographic processes. Elephants are important seed-dispersing agents. We studied frugivory and seed dispersal by Asian Elephants in the tropical deciduous and thorn forests of the Nilgiri Biosphere Reserve, southern India. We determined fruit consumption based on the presence of seeds and fruit remnants in elephant dung piles. In total, we identified seeds of eight plant species belonging to seven families in 16% out of 455 dung piles examined between 1991 and 2004. Coinciding with a peak fruiting season in the study area, seeds and other fruit parts appeared in the dung piles significantly more frequently during the dry season than in the wet seasons (southwest and northeast monsoons). Owing to differences in fruit species abundance in different habitats, there was more evidence of fruit consumption in the dry thorn than in the dry and moist deciduous forests. This corresponds with insufficient grass availability in thorn forests during the dry season and an increase in browse consumption as a supplementary diet. Seeds of Tamarindus indica and Acacia intsia were found in elephant dung more frequently than other species. Seed and fruit remnants were found in almost an equal number of dung piles of both bulls and herds.

New evidence for self‐medication in bonobos: Manniophyton fulvum leaf‐ and stemstrip‐swallowing from LuiKotale, Salonga National Park, DR Congo

The swallowing of entire leaves by apes across Africa without chewing has been observed for over 40 plant species. Here we add evidence for (a) a new site, LuiKotale where leaf‐swallowing of Manniophyton fulvum (Euphorbiaceae) is observed in bonobos, (b) a so far unreported ingestion of unchewed stemstrips of M. fulvum, we name stemstrip‐swallowing; and (c) a test of some of the requirements put forward by Huffman for the assessment of plants ingested for medical purpose. As ecological correlates we analyzed M. fulvum phenological data and examined 1,094 dung piles collected between 2002 and 2009. By that we assessed availability and choice of leaves. In addition, we provide the first full description of the behavior related to this plant species' use by chimpanzees or bonobos using 56 bouts of M. fulvum ingestion observed between October 2007 and February 2010. With these data we tested and met 4 of the 6 requirements given by Huffman, supporting ingestion of this species as self‐medication. Despite species' year‐round availability and abundance, M. fulvum was ingested only at specific times, in very small amounts, and by a small proportion of individuals per party. In the absence of our own parasitological data, we used M. fulvum swallowing as evidence for parasite infestation, and seasonality as a proxy for stressors underlying seasonal fluctuation and impacting immune responses. Using these indirect factors available, we investigated conditions for a parasite to develop to its infective stage as well as conditions for the host to cope with infections. Both rain and temperature were good predictors for M. fulvum ingestion. We discuss the use of M. fulvum with respect to its hispidity and subsequent purging properties and provide insight into its ethnomedicinal uses by humans, stimulating speculations about potentially additional pharmacological effects. Am. J. Primatol. 76:146–158, 2014. © 2013 Wiley Periodicals, Inc.

Can molecular data validate morphometric identification of faecal pellets in Tanzanian forest antelope species?

Forest-dwelling antelope species are often difficult to detect during surveys due to their cryptic behaviour and densely vegetated habitats. Dung counts have traditionally been used to infer forest antelope abundance but genetic identification has shown that visual identification of ungulate dung to species is often unreliable. This study attempted to use easily obtained morphometric data from faecal pellets to statistically assign antelope dung piles to species. We measured pellets from 238 dung piles collected from the Udzungwa Mountains, south-central Tanzania, a largely forested landscape with five forest-associated antelope species including the endangered Abbott’s duiker Cephalophus spadix. The species identity of sampled dung piles was determined by amplifying a c. 600 bp fragment of the mitochondrial control region and aligning DNA sequences with published references. We found no diagnostic differences in faecal pellet size between antelope species although there were significant differences in mean pellet length and width. We employed a single variable linear discriminant analysis to predict the species of dung piles based on pellet length. Despite significant differentiation between species we obtained an overall accuracy of 58.8 % that did not meet our specified probability threshold (P < 0.05). Abbott’s duiker dung piles were correctly assigned in the majority of cases (74 %). Overall, morphometric assignment of dung piles to species was not accurate enough to validate dung counts as a survey method for forest antelope although our results do not preclude the development of alternative field identification methods using additional non-molecular characters.

Nest-Site Selection and Success of Red Shoveler (Anas platalea) in a Wetland of Central Chile

Abstract. Understanding the factors that determine waterfowl nesting site selection is an essential tool for wetland management, but, unfortunately, this information is lacking for most species in the Southern Hemisphere. During the 2007 breeding season, reproductive biology and nesting habitat selection of the Red Shoveler (Anas platalea) were investigated in a wetland of Central Chile. Red Shoveler nests were clumped, primarily in scrubby meadows, containing an average of 8.56 ± 1 eggs (n = 2 3). Nesting microhabitat was characterized by well-covered ground and an intermediate height of the rich herbaceous layer close to the water. Hatching success was 80 ± 20% and was negatively associated with the number of cattle dung piles and the proportion of dry vegetation, but positively explained by herbaceous height and the distance to watercourse. Results suggest that the risk of predation, the access to food, and cattle disturbance would affect the selection of breeding sites and nest success of Red Shoveler...

Frugivory and seed dispersal of woody species by the Asian elephant (Elephas maximus) in a mid-elevation tropical evergreen forest in India

Abstract:Frugivory and seed dispersal by the Asian elephant, Elephas maximus, in a mid-elevation tropical evergreen forest in India was studied by dung analysis and conducting seed germination trials on ingested and control seeds. A total of 384 dung piles were observed during the period February 2007 to December 2008. Fruits/seeds and seedlings of 27 woody species were observed from the dung piles. Seed germination experiments showed that seeds from dung were viable and germination time of ingested seeds was significantly lower than that of control seeds. It was observed that 43.6% of the seedlings in the dung piles established as saplings. The study suggests that the Asian elephant is a legitimate seed disperser in tropical forests in its range.

Dung Beetles Use the Milky Way for Orientation

When the moon is absent from the night sky, stars remain as celestial visual cues. Nonetheless, only birds, seals, and humans are known to use stars for orientation. African ball-rolling dung beetles exploit the sun, the moon, and the celestial polarization pattern to move along straight paths, away from the intense competition at the dung pile. Even on clear moonless nights, many beetles still manage to orientate along straight paths. This led us to hypothesize that dung beetles exploit the starry sky for orientation, a feat that has, to our knowledge, never been demonstrated in an insect. Here, we show that dung beetles transport their dung balls along straight paths under a starlit sky but lose this ability under overcast conditions. In a planetarium, the beetles orientate equally well when rolling under a full starlit sky as when only the Milky Way is present. The use of this bidirectional celestial cue for orientation has been proposed for vertebrates, spiders, and insects, but never proven. This finding represents the first convincing demonstration for the use of the starry sky for orientation in insects and provides the first documented use of the Milky Way for orientation in the animal kingdom.

Dung beetles ignore landmarks for straight-line orientation

Upon locating a suitable dung pile, ball-rolling dung beetles shape a piece of dung into a ball and roll it away in a straight line. This guarantees that they will not return to the dung pile, where they risk having their ball stolen by other beetles. Dung beetles are known to use celestial compass cues such as the sun, the moon and the pattern of polarised light formed around these light sources to roll their balls of dung along straight paths. Here, we investigate whether terrestrial landmarks have any influence on straight-line orientation in dung beetles. We find that the removal or re-arrangement of landmarks has no effect on the beetle's orientation precision. Celestial compass cues dominate straight-line orientation in dung beetles so strongly that, under heavily overcast conditions or when prevented from seeing the sky, the beetles can no longer orient along straight paths. To our knowledge, this is the only animal with a visual compass system that ignores the extra orientation precision that landmarks can offer.

Dung beetles use their dung ball as a mobile thermal refuge

At midday, surface temperatures in the desert often exceed 60°C. To be active at this time, animals need extraordinary behavioural or physiological adaptations. Desert ants, for instance, spend up to 75% of their foraging time cooling down on elevated thermal refuges such as grass stalks. Ball-rolling dung beetles work under similar thermal conditions in South African savannahs. After landing at a fresh dung pile, a beetle quickly forms a dung ball and rolls it away in a straight line, head down, walking backwards. Earlier studies have shown that some dung beetles maintain an elevated body temperature to gain a competitive advantage, and that heat shunting may prevent overheating during flight. However, we know little about the behavioural strategies beetles might employ to mitigate heat stress while rolling their dung balls. Using infrared thermography and behavioural experiments, we show here that dung beetles use their dung ball as a mobile thermal refuge onto which they climb to cool down while rolling across hot soil. We further demonstrate that the moist ball functions not only as a portable platform, but also as a heat sink, which effectively cools the beetle as it rolls or climbs onto it.