Porter Amy, Eckardt Winnie, Vecellio Veronica, Guschanski Katerina, Niehoff Peter Philip, Ngobobo-As-Ibungu Urbain, Nishuli Pekeyake Radar, Stoinski Tara, Caillaud Damien
The Dian Fossey Gorilla Fund International, Atlanta, GA, United States of America.
Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala Universitet, Uppsala, Sweden.
PeerJ. 2019 Apr 2;7:e6655. doi: 10.7717/peerj.6655. eCollection 2019.
Humans were once considered unique in having a concept of death but a growing number of observations of animal responses to dying and dead conspecifics suggests otherwise. Complex arrays of behaviors have been described ranging from corpse removal and burial among social insects to quiet attendance and caregiving among elephants and primates. Less frequently described, however, are behavioral responses of individuals from different age/sex classes or social position toward the death of conspecifics. We describe behavioral responses of mountain gorillas () to the deaths of a dominant silverback and a dominant adult female from the same social group in Volcanoes National Park in Rwanda and the responses of Grauer's gorillas () to the corpse of an extra-group silverback in Kahuzi-Biega National Park, Democratic Republic of Congo. In gorillas, interactions between groups or with a lone silverback often result in avoidance or aggression. We predicted that: (i) more individuals should interact with the corpses of same-group members than with the corpse of the extra-group silverback; (ii) adult females with infants should avoid the corpse of the extra-group silverback; and (iii) in the mountain gorilla cases, individuals that shared close social relationships with the dead individual should spend more time with the corpse than other individuals in the group. We used a combination of detailed qualitative reports, photos, and videos to describe all occurrences of affiliative/investigative and agonistic behaviors observed at the corpses. We observed similar responses toward the corpses of group and extra-group individuals. Animals in all three cases showed a variety of affiliative/investigative and agonistic behaviors directed to the corpses. Animals of all age/sex classes interacted with the corpses in affiliative/investigative ways but there was a notable absence of all adult females at the corpse of the extra-group silverback. In all three cases, we observed only silverbacks and blackbacks being agonistic around and/or toward the corpses. In the mountain gorilla cases, the individuals who spent the most time with the corpses were animals who shared close social relationships with the deceased. We emphasize the similarity in the behavioral responses around the corpses of group and extra-group individuals, and suggest that the behavioral responses were influenced in part by close social relationships between the deceased and certain group members and by a general curiosity about death. We further discuss the implications close interactions with corpses have for disease transmission within and between gorilla social groups.
人类曾被认为是唯一具有死亡概念的生物，但越来越多关于动物对濒死和死亡同种个体反应的观察结果表明并非如此。已经描述了一系列复杂的行为，从群居昆虫的尸体移除和埋葬到大象和灵长类动物的安静陪伴和照料。然而，较少被描述的是来自不同年龄/性别类别或社会地位的个体对同种个体死亡的行为反应。我们描述了卢旺达火山国家公园中，山地大猩猩（）对同一社会群体中一只占主导地位的银背大猩猩和一只占主导地位的成年雌性大猩猩死亡的行为反应，以及刚果民主共和国卡胡兹 - 别加国家公园中，格雷厄姆大猩猩（）对一只外来群体银背大猩猩尸体的反应。在大猩猩中，群体之间或与一只独居银背大猩猩的互动通常会导致回避或攻击行为。我们预测：（i）与外来群体银背大猩猩的尸体相比，更多个体应该会与同群体成员的尸体进行互动；（ii）携带幼崽的成年雌性应该会回避外来群体银背大猩猩的尸体；（iii）在山地大猩猩的案例中，与死亡个体有着密切社会关系的个体应该会比群体中的其他个体在尸体旁停留更长时间。我们结合详细的定性报告、照片和视频来描述在尸体旁观察到的所有亲和/探究行为和攻击行为。我们观察到对群体个体和外来群体个体尸体的类似反应。在所有三个案例中，动物都表现出了针对尸体的各种亲和/探究行为和攻击行为。所有年龄/性别类别的动物都以亲和/探究的方式与尸体互动，但在外来群体银背大猩猩的尸体旁明显没有成年雌性出现。在所有三个案例中，我们只观察到银背大猩猩和黑背大猩猩在尸体周围和/或朝向尸体表现出攻击行为。在山地大猩猩的案例中，在尸体旁停留时间最长的个体是与死者有着密切社会关系的动物。我们强调围绕群体个体和外来群体个体尸体的行为反应具有相似性，并表明行为反应部分受到死者与某些群体成员之间密切社会关系以及对死亡的普遍好奇心的影响。我们进一步讨论了与尸体的密切互动对大猩猩社会群体内部和之间疾病传播的影响。
