Thanatological Events and Scavenging on the Carcass of a Black Snub-Nosed Monkey (Rhinopithecus strykeri)

The responses of nonhuman primates towards conspecific deaths in the wild, and the activities of carnivores scavenging the corpses, are different but interconnected thanatological and ecological aspects of wildlife mortality. We report the first thanatological events observed in a wild, multilevel group of Myanmar or black snub-nosed monkeys (Rhinopithecus strykeri [R. strykeri]) and mesocarnivores scavenging on a monkey carcass in the Pianma region, near the China-Myanmar border. We detected two freshly deceased carcasses during field surveys. The group members visited the location of their recently deceased conspecific twice and variously looked down at the carcass, emitted alarm calls and unusual contact calls, hugged social partners and prevented approaches by individuals from other social units. These behaviors suggest strong bonds and emotional reactions to the death of a companion in R. strykeri. Infrared camera trapping revealed the Siberian weasel (Mustela sibirica) as the principal scavenger on the carcass, followed by the yellow-throated marten (Martes flavigula). Siberian weasels showed greater activity levels and time spent feeding on the R. strykeri carcass when it was fresh, while remaining vigilant for potential competitors and predators. After the carcass was largely consumed and decayed, both frequency and duration of feeding and vigilance behaviors decreased.