Leopard predation on wild Sichuan snub-nosed monkeys.

Predation is widely recognized as a powerful selective pressure on primate behavior and ecology, although knowledge of predator-prey relationships remains limited partly due to the rarity of directly observed attacks on primates. Here, we describe four confirmed or suspected instances of leopard (Panthera pardus) predation on free-ranging Sichuan (golden) snub-nosed monkeys (Rhinopithecus roxellana), a highly endangered colobine species endemic to China. We recorded predation events and the reactions of monkey group members.

Ethical Challenges of the COVID-19 Pandemic: A Japanese Perspective.

This article focuses on how Japan experienced the COVID-19 pandemic. It delineates the various challenges the country faced and the measures the national government took to stop the spread of the infection. The article begins with the author's personal experience of COVID-19.

Maternal caretaking behavior towards a dead juvenile in a wild, multi-level primate society.

Maternal caretaking and transport of dead infants are widespread among nonhuman primates, having been reported in numerous species of monkeys and apes. By contrast, accounts of such behaviors toward dead juveniles are scarce. Here, we describe responses by the mother and other group members to the death of a juvenile in a wild, multi-level group of Sichuan snub-nosed monkeys (Rhinopithecus roxellana).

Mirror self-recognition in gorillas (Gorilla gorilla gorilla): a review and evaluation of mark test replications and variants.

Mirror self-recognition (MSR), widely regarded as an indicator of self-awareness, has not been demonstrated consistently in gorillas. We aimed to examine this issue by setting out a method to evaluate gorilla self-recognition studies that is objective, quantifiable, and easy to replicate. Using Suarez and Gallup's (J Hum Evol 10:175-183, 1981) study as a reference point, we drew up a list of 15 methodological criteria and assigned scores to all published studies of gorilla MSR for both methodology and outcomes.

Putting the cart before the horse: claims for mirror self-recognition in horses are unfounded.

The recent article by Baragli, Scopa, Maglieri, and Palagi (Anim Cogn https://doi.org/10.1007/s10071-021-01502-7 , 2021) that claims to demonstrate mirror self-recognition (MSR) in horses is not based on compelling evidence.

Nesting, sleeping, and nighttime behaviors in wild and captive great apes.

The past few decades have seen a burgeoning of scientific studies on great apes' use of nests for sleeping in the wild, as well as their nesting behavior and sleep in captivity. We review recent advances in knowledge of these topics, with the aim of promoting information exchange between people working in the field and with captive great apes. We trace developments in research into nest-building techniques in adults and immatures, factors that influence selection of general sleeping sites and specific locations, social aspects of sleep, postures, and nighttime activities.

The "olfactory mirror" and other recent attempts to demonstrate self-recognition in non-primate species.

The recent attempt by Horowitz (2017) to develop an "olfactory mirror" test of self-recognition in domestic dogs raises some important questions about the kinds of data that are required to provide definitive evidence for self-recognition in dogs and other species. We conclude that the "olfactory mirror" constitutes a compelling analog to the mark test for mirror self-recognition in primates, but despite claims to the contrary neither dogs, elephants, dolphins, magpies, horses, manta rays, squid, nor ants have shown compelling, reproducible evidence for self-recognition in any modality.

Third-party social evaluations of humans by monkeys and dogs.

Developmental psychologists are increasingly interested in young children's evaluations of individuals based on third-party interactions. Studies have shown that infants react negatively to agents who display harmful intentions toward others, and to those who behave unfairly. We describe experimental studies of capuchin monkeys' and pet dogs' differential reactions to people who are helpful or unhelpful in third-party contexts, and monkeys' responses to people who behave unfairly in exchanges of objects with a third party.

Reflections in the rainforest: full-length mirrors facilitate behavioral observations of unhabituated, wild chimpanzees.

We describe behaviors of unhabituated wild chimpanzees in Gabon during repeated encounters with large mirrors installed permanently in their home range. Movement in proximity to the mirrors triggered video cameras that recorded the scene. Data are presented for 51 mirror encounters spanning a 3-year period.

Comparative thanatology.

A quick guide on comparative thanatology, the study of death and dying, particular how individuals respond to a conspecific's death, across animal phylogeny.

Tending a dying adult in a wild multi-level primate society.

Responses of nonhuman species to dying and dead conspecifics range from hard-wired, fixed-action patterns - as in social insects - to varied, flexible behaviors with cognitive and emotional correlates - as in some larger-brained mammals [1,2]. Comparative thanatology addresses issues that include empathy, compassion, and conceptual understanding of death across species [1-3]. Several aspects of how great apes react to illness, injury and death of others recall human behavior in comparable situations [1-5].

Evaluation of third-party reciprocity by squirrel monkeys (Saimiri sciureus) and the question of mechanisms.

Social evaluation during third-party interactions emerges early in human ontogeny, and it has been shown in adult capuchin monkeys who witness violations of reciprocity in object exchanges: Monkeys were less inclined to accept food from humans who refused to reciprocate with another human. A recent study reporting similar evidence in marmoset monkeys raised the possibility that such evaluations might be based on species' inherent cooperativeness. We tested a species not renowned for cooperativeness-squirrel monkeys-using the procedure used with marmosets and found a similar result.

Mirror self-recognition: a review and critique of attempts to promote and engineer self-recognition in primates.

We review research on reactions to mirrors and self-recognition in nonhuman primates, focusing on methodological issues. Starting with the initial demonstration in chimpanzees in 1970 and subsequent attempts to extend this to other species, self-recognition in great apes is discussed with emphasis on spontaneous manifestations of mirror-guided self-exploration as well as spontaneous use of the mirror to investigate foreign marks on otherwise nonvisible body parts-the mark test. Attempts to show self-recognition in other primates are examined with particular reference to the lack of convincing examples of spontaneous mirror-guided self-exploration, and efforts to engineer positive mark test responses by modifying the test or using conditioning techniques.