Dung beetle response to fire, grazing and experimental trap design
Middleton, Gregory, Jr.
Citations
Abstract
Dung beetles (Coleoptera: Scarabaeidae) are important members of many ecosystems that contribute to dung decomposition and nutrient cycling. Dung beetle populations, however, have been in decline recently due to factors including habitat loss, increasing CO2 levels and anthelmintics like ivermectin, used to treat cattle parasites. Baited in ground pitfall traps are the most common method for capturing and observing dung beetles but are prohibited or unsuitable in some areas. Three alternative trap methods were deployed, and none were found to have a higher capture rate when compared to in-ground pitfall traps. Only 137 beetles were captured in the comparative study and additional trap development is warranted. Dung beetles are attracted to dung of large grazers including cattle and bison. Oklahoma has remnant prairies that support grazing along with improved pasture lands for beef animals. These areas need to be preserved for their biodiversity, and one management technique is prescribed burns. The effects of fire and types of grazers on dung beetles in the southern Great Plains has not been well-researched. Dung beetles were sampled in recently burned patches and recorded for one, four and nine weeks after the burn. Directly following a burn, dung beetle numbers were lower but recovered within 4 weeks. At the tallgrass prairie, 4,811 dung beetles were associated with bison grazing compared with 560 associated with cattle and goat grazing. These studies demonstrate that burning and mixed animal grazing maintain dung beetle communities.