Scraping behavior of black rhinoceros is related to age and fecal gonadal metabolite concentrations

Abstract

Black rhinoceroses (Diceros bicornis) defecate in middens and frequently use sharp kicking motions to scatter their feces in large and conspicuous scrapings. Although these fecal markings are believed to be advertisements to conspecifics, the type of information that might be encoded has not been investigated. Because of the secretive nature of black rhinos, we used camera traps to identify individuals scraping their feces in 2 sections of Addo Elephant National Park, South Africa. We collected fecal samples (n = 137; July 2009-November 2010) from known individuals (captured on photo), gathered data about fecal scrapings (e.g., length and location), and analyzed samples for concentrations of fecal progestagen and androgen metabolites. We predicted that the physical and chemical aspects of the fecal scrapings were related to the sex, age, and reproductive state (e.g., fecal gonadal metabolite concentration) of the black rhinos. Lengths of fecal scrapings increased with age for both sexes and were negatively related to concentrations of fecal progestagen metabolites for females. Males scraped more than females, whereas females were more likely to scrape next to a bush. Similar to other territorial species, black rhino fecal markings seemed to advertise the territories of adult males and communicate about the sexual status of the female. © 2014 American Society of Mammalogists.