Dung beetles, a diverse group of insects primarily within the Scarabaeidae family, play a significant role in ecosystems worldwide. These beetles are nature’s recyclers, consuming and burying animal waste, which contributes to nutrient cycling, soil health, and pest suppression. Their presence is widespread across a remarkable array of global environments.
Global Habitat Preferences
Dung beetles thrive in environments with a consistent supply of mammalian dung, their primary food source. They inhabit various biomes, including deserts, grasslands, savannas, and both native and planted forests. These insects generally prefer moderate climates. They are particularly abundant in areas with high densities of large herbivores.
Distribution Across Continents
Dung beetles are found on every continent except Antarctica.
Africa, particularly its savannas, boasts high diversity, with over 2,000 species known. Their distribution is influenced by rainfall and temperature, and many are important for maintaining healthy grasslands.
Asia is home to numerous species, with significant diversity in tropical forests and regions like the Malay Peninsula, India, and Southeast Asia. Forest habitats are important for maintaining diverse communities.
Europe supports approximately 460 species, found in pastures, game parks, and various forest types. Some European species are endangered, with conservation efforts focused on reintroduction to suitable habitats with abundant wild herbivore dung.
North America has about 75 to 90 native species, inhabiting diverse landscapes such as farmlands, forests, rangelands, prairies, and deserts. Onthophagus hecate is a common species widely distributed across the continent.
South America holds the highest global diversity, with a rich fauna in its Neotropical forests. Many species in South American pastures are native to natural grasslands, contributing to cattle manure recycling across biomes like the Cerrado, Pampa, and Amazon Forest.
Australia has over 500 native species, historically adapted to the dry, pelleted dung of marsupials. To address the large amounts of moist cattle dung introduced with European livestock, 29 exotic species from Africa and Europe have been introduced and are established across most of mainland Australia, especially in agricultural regions.
Factors Influencing Their Range
The geographical range of dung beetles is shaped by several environmental and ecological factors. Climate, particularly temperature and rainfall, influences their activity and overall distribution. Different species have specific temperature preferences, and higher temperatures can reduce their specialization on certain dung types. Soil composition is another determinant, affecting the ability of burrowing species to construct nests and tunnels; sandy soils often encourage tunneling behavior, while clay content and water table depth also play roles.
The availability and type of dung from various animals are important for dung beetle survival. They prefer fresh dung from herbivores and omnivores, and dung quality, including its moisture and nutrient content, dictates suitability. The presence of large mammal populations is important for supporting dung beetle communities. Vegetation cover also influences their distribution, with tropical forests and savannas supporting the highest diversity. Open habitats and closed-canopy forests can favor different species, and shade within a habitat can positively influence beetle diversity.
Human land use practices, such as agriculture, deforestation, and urbanization, impact dung beetle populations. Converting natural forests to agricultural lands or pastures often leads to a decline in species richness and shifts in community composition, partly due to reduced wild mammal populations and the use of chemicals like antiparasitics in livestock.
Absence in Extreme Climates
Dung beetles are absent or scarce in environments characterized by extreme climatic conditions. They are not found in Antarctica, due to the lack of suitable temperatures and consistent dung sources. These insects also avoid extremely cold or dry weather, limiting their presence in polar regions, very high altitudes, and arid deserts. Such environments lack the necessary conditions, including moderate temperatures, sufficient moisture, and a reliable supply of fresh dung, for most species to survive and reproduce.