Coprophagy-related interspecific nocturnal interactions between Japanese macaques (Macaca fuscata yakui) and sika deer (Cervus nippon yakushimae)

Co-cultures: exploring interspecies culture among humans and other animals

The concept of 'co-culture' is introduced as a novel framework for understanding the mutual cultural evolution between animal species, including, but not only, humans. It explores the dynamics of interspecies interactions, particularly in how different species influence each other's behavioural and cognitive adaptations. Various instances of interspecies cultural exchange are highlighted, such as the acquisition of medicinal plants from animals resulting in a shared medicinal culture, adaptive behaviours of urban wildlife, and cooperative behaviours between animal species. Co-culture challenges the notion of species-specific culture, underscoring the complexity and interconnectedness of human and animal societies, and between animal societies. Further research into co-culture is advocating and emphasising its implications for conservation, urban planning, and a deeper understanding of animal cognition and behaviour.

A review of interspecific social play among nonhuman animals

BROOKS, H.J.B. & G.M. Burghardt. A comparative review of interspecific social play among nonhuman animals. NEUROSCI BIOBEHAV REV XX(X) XXX-XXX, XXXX.- Few species play socially with another species, hereafter called interspecific social play (ISP). ISP involves reading and responding appropriately to social cues of other species, often taxonomically remote, and has implications for perception, communication, and cognition. We reviewed information on non-human ISP from both print media and videos from YouTube and Reddit. We found over 200 instances of ISP. The literature predominantly featured wild primates, carnivores, and marine mammals. Carnivores and terrestrial ungulates were common in videos. ISP in avian and reptile species were found in both sources, including instances of playing with mammals. Animals may engage in ISP because it is risky and stimulating, they lack age-appropriate conspecifics, the play motivation is high, or to maintain social bonds in mixed-species groups. Cataloguing ISP uncovers which species are interacting and how. Systematic studies of ISP are difficult and many reports are brief and anecdotal. Minimally, future research should record information about each observation, including the age, sex, and history of participants.

External environmental conditions impact nocturnal activity levels in proboscis monkeys (Nasalis larvatus) living in Sabah, Malaysia

Recently, several diurnal nonhuman anthropoids have been identified displaying varying degrees of nocturnal activity, which can be influenced by activity “masking effects”—external events or conditions that suppress or trigger activity, temporarily altering normal activity patterns. Environmental masking characteristics include nocturnal temperature, rainfall, cloud cover, and moon brightness. Similarly, other ecological characteristics, including proximity to humans and predators and daytime activity, may also trigger or suppress nocturnal activity. Understanding the effects of external conditions on activity patterns is pertinent to effective species conservation. We investigated the presence of nocturnal activity and the influence of masking effects on the level of nocturnal activity displayed by wild proboscis monkeys (Nasalis larvatus) in Sabah, Malaysian Borneo. Dual‐axis accelerometers were attached by collar to six male proboscis monkeys from different one‐male, multi‐female groups to record activity continuously (165–401 days each). We measured the monkeys' nocturnal and diurnal activity levels and investigated the effects of seven potential masking effects. Nocturnal activity was much lower than diurnal activity. Still, proboscis monkeys did display varying levels of nocturnal activity. Generalized linear mixed models identified higher nocturnal activity in the study individuals during nights with cooler temperatures, higher rainfall, and after higher diurnal activity. These three masking effects affected nocturnal activity levels during the observation period that informed our model, although they did not predict nocturnal activity outside of this period. While the generalizability of these results remains uncertain, this study highlights the utility of accelerometers in identifying activity patterns and masking effects that create variability in these patterns.

Six male proboscis monkeys displayed low levels of nocturnal activity, consistent with a diurnal activity pattern.

Nocturnal activity in five of these male proboscis monkeys increased during nights that had cooler temperatures, higher rainfall, and after higher daytime activity.

Between forest and croplands: Nocturnal behavior in wild chimpanzees of Sebitoli, Kibale National Park, Uganda

Some animal species have been presumed to be purely diurnal. Yet, they show flexibility in their activity rhythm, and can occasionally be active at night. Recently, it has been suggested that chimpanzees may rarely engage in nocturnal activities in savannah forests, in contrast to the frequent nocturnal feeding of crops observed at Sebitoli, Kibale National Park, Uganda. Here we thus aimed to explore the factors that might trigger such intense nocturnal activity (e.g. harsher weather conditions during daytime, low wild food availability or higher diurnal foraging risk) in this area. We used camera-traps set over 18 km2 operating for 15 months. We report activities and group composition from records obtained either within the forest or at the forest interface with maize fields, the unique crop consumed. Maize is an attractive and accessible food source, although actively guarded by farmers, particularly during daytime. Out of the 19 156 clips collected, 1808 recorded chimpanzees. Of these, night recordings accounted for 3.3% of forest location clips, compared to 41.8% in the maize fields. Most nocturnal clips were obtained after hot days, and most often during maize season for field clips. At night within the forest, chimpanzees were travelling around twilight hours, while when at the border of the fields they were foraging on crops mostly after twilight and in smaller parties. These results suggest that chimpanzees change their activity rhythm to access cultivated resources when human presence and surveillance is lower. This survey provides evidence of behavioral plasticity in chimpanzees in response to neighboring human farming activities, and emphasizes the urgent need to work with local communities to mitigate human-wildlife conflict related to crop-feeding.

Activity synchrony and travel direction synchrony in wild female Japanese macaques

The degree of behavioural synchrony of animals within a group can be considered a reflection of how individuals adjust their behaviours to manage the costs/benefits accompanying group-living. In this study, we focused on activity synchrony and travel direction synchrony as behavioural synchrony. We aimed to quantify the degree of behavioural synchrony and identify which factors can affect the synchrony in wild females of Japanese macaques. Japanese macaques live in female philopatric multi-female and multi-male groups and have a linear dominance hierarchy. The groups are characterized by changing spatio-temporal cohesiveness among group members. Two observers conducted simultaneous focal animal sampling on adult females using global positioning system devices to record locations. The overall degree of activity synchrony was positive compared with random, and the degree was highest when macaques were located within visual range of each other. Both activity synchrony and travel direction synchrony were influenced by spatial cohesion, i.e. interindividual distance, which shows that the probabilities of synchrony were higher with individuals located closer. Activity synchrony was also influenced by activity type, showing that the probabilities of synchrony were higher when individuals engaged in foraging. These results suggest that synchronized foraging may be caused by enhanced feeding with other group members when they are closer to each other. Our approach to quantitatively measure spatial dispersal while observing group members simultaneously revealed the roles of spatial cohesion and activity types for determining the degree of behavioral synchrony.

Nocturnal activity in wild chimpanzees (Pan troglodytes): Evidence for flexible sleeping patterns and insights into human evolution

OBJECTIVES

We investigated occurrences and patterns of terrestrial nocturnal activity in wild chimpanzees (Pan troglodytes) and modelled the influence of various ecological predictors on nocturnal activity.

METHODS

Data were extracted from terrestrial camera-trap footage and ecological surveys from 22 chimpanzee study sites participating in the Pan African Programme: The Cultured Chimpanzee. We described videos demonstrating nocturnal activity, and we tested the effects of the percentage of forest, abundance of predators (lions, leopards and hyenas), abundance of large mammals (buffalos and elephants), average daily temperature, rainfall, human activity, and percent illumination on the probability of nocturnal activity.

RESULTS

We found terrestrial nocturnal activity to occur at 18 of the 22 study sites, at an overall average proportion of 1.80% of total chimpanzee activity, and to occur during all hours of the night, but more frequently during twilight hours. We found a higher probability of nocturnal activity with lower levels of human activity, higher average daily temperature, and at sites with a larger percentage of forest. We found no effect of the abundance of predators and large mammals, rainfall, or moon illumination.

DISCUSSION

Chimpanzee terrestrial nocturnal activity appears widespread yet infrequent, which suggests a consolidated sleeping pattern. Nocturnal activity may be driven by the stress of high daily temperatures and may be enabled at low levels of human activity. Human activity may exert a relatively greater influence on chimpanzee nocturnal behavior than predator presence. We suggest that chimpanzee nocturnal activity is flexible, enabling them to respond to changing environmental factors.

Deer Mates: A Quantitative Study of Heterospecific Sexual Behaviors Performed by Japanese Macaques Toward Sika Deer

This is the first quantitative study of heterospecific sexual behavior between a non-human primate and a non-primate species. We observed multiple occurrences of free-ranging adolescent female Japanese macaques (Macaca fuscata) performing mounts and sexual solicitations toward sika deer (Cervus nippon) at Minoo, central Japan. Our comparative description of monkey-deer versus monkey-monkey interactions supported the "heterospecific sexual behavior" hypothesis: the mounts and demonstrative solicitations performed by adolescent female Japanese macaques toward sika deer were sexual in nature. In line with our previous research on the development of homospecific sexual behavior in immature female Japanese macaques, this study will allow us to test other hypotheses in the future, such as the "practice for homospecific sex," the "safe sex," the "homospecific sex deprivation," the "developmental by-product," and the "cultural heterospecific sex" hypotheses. Further research will be necessary to ascertain whether this group-specific sexual behavior was a short-lived fad or an incipient cultural phenomenon and may also contribute to better understanding the proximate and ultimate causes of reproductive interference.

Activity of wild Japanese macaques in Yakushima revealed by camera trapping: Patterns with respect to season, daily period and rainfall

Animals are subject to various scales of temporal environmental fluctuations, among which daily and seasonal variations are two of the most widespread and significant ones. Many biotic and abiotic factors change temporally, and climatic factors are particularly important because they directly affect the cost of thermoregulation. The purpose of the present study was to determine the activity patterns of wild Japanese macaques (Macaca fuscata) with a special emphasis on the effect of thermal conditions. We set 30 camera traps in the coniferous forest of Yakushima and monitored them for a total of 8658 camera-days between July 2014 and July 2015. Over the one-year period, temperature had a positive effect, and rainfall had a negative effect on the activity of macaques during the day. Capture rate was significantly higher during the time period of one hour after sunrise and during midday. During winter days, macaques concentrated their activity around noon, and activity shifted from the morning toward the afternoon. This could be interpreted as macaques shifting their activity to warmer time periods within a single day. Japanese macaques decreased their activity during the time before sunrise in seasons with lower temperatures. It was beneficial for macaques to be less active during cooler time periods in a cold season. Even small amounts of rainfall negatively affected the activity of Japanese macaques, with capture rates decreasing significantly even when rainfall was only 0.5-1 mm/min. In conclusion, thermal conditions significantly affected the activity of wild Japanese macaques at various time scales.

Interspecies sexual behaviour between a male Japanese macaque and female sika deer

Interspecies sexual behaviour or 'reproductive interference' has been reported across a wide range of animal taxa. However, most of these occurrences were observed in phylogenetically close species and were mainly discussed in terms of their effect on fitness, hybridization and species survival. The few cases of heterospecific mating in distant species occurred between animals that were bred and maintained in captivity. Only one scientific study has reported this phenomenon, describing sexual harassment of king penguins by an Antarctic fur seal. This is the first article to report mating behaviour between a male Japanese macaque (Macaca fuscata yakui) and female sika deer (Cervus nippon yakushimae) on Yakushima Island, Japan. Although Japanese macaques are known to ride deer, this individual showed clearly sexual behaviour towards several female deer, some of which tried to escape whilst others accepted the mount. This male seems to belong to a group of peripheral males. Although this phenomenon may be explained as copulation learning, this is highly unlikely. The most realistic hypothesis would be that of mate deprivation, which states that males with limited access to females are more likely to display this behaviour. Whatever the cause for this event may be, the observation of highly unusual animal behaviour may be a key to understanding the evolution of heterospecific mating behaviour in the animal kingdom.

Detection of Cyclospora in captive chimpanzees and macaques by a quantitative PCR-based mutation scanning approach

BACKGROUND

Cyclospora is a protistan parasite that causes enteritis in several species of animals including humans. The aim of this study was to investigate the presence of Cyclospora in captive non-human primates.

METHODS

A total of 119 faecal samples from Pan troglodytes, Macaca sylvanus, Cercopithecus cephus, Erythrocebus patas, Chlorocebus aethiops and Macaca fascicularis from a wildlife animal rescue center as well as from Macaca fascicularis from an experimental primate research center were tested for the presence of Cyclospora by quantitative real-time PCR (qPCR) and single-strand conformation polymorphism (SSCP) analysis.

RESULTS

Cyclospora was detected in three Pan troglodytes (13.6%) and nine (9.3%) Macaca fascicularis.

CONCLUSIONS

The present study represents the first record of Cyclospora in captive primates in Europe, suggesting the presence of Cyclospora cayetanensis, which is transmissible to humans.

Sleep duration is affected by social relationships among sleeping partners in wild Japanese macaques

Co-sleeping behaviour, such as sharing a sleeping site or bed, should play an important role in determining sleep structure in mammals by mitigating predation pressure and harsh abiotic conditions during sleep. Although environmental factors surrounding sleeping sites have been studied, there is very little information on the effects of the social environment within the site on sleep in animals other than humans. Here, we quantified the duration of nighttime sleep of wild primates during behavioural observations. Wild Japanese macaques (Macaca fuscata yakui) form clusters at sleeping sites, where they huddle with group members. Macaques slept for longer when huddled in sleeping clusters with natal members than in those with non-natal members. A high degree of synchronisation of wakefulness in pairs of macaques huddling in non-natal clusters suggested that their sleep was often interrupted by the wakefulness of huddling members at night. Our results suggest that familiarity and closeness to huddling partners influence sleep duration.

What makes wild chimpanzees wake up at night?

I examined the possible cause of night awakening among wild chimpanzees (Pan troglodytes) in Mahale Mountains National Park, Tanzania. Chimpanzee vocalizations and activity-related sounds (CVSs) were used to indicate awakening because I was unable to visually observe them. Over a 5-night observation period, CVSs (n = 128) were heard every night, and most (n = 91) were observed within 5 min of previous CVSs. Chimpanzees use CVSs as social communication to maintain spatial contact with other chimpanzees who occasionally travel at night. The first sound in a sequence of CVSs (CVS bout) was heard immediately following the vocalization or sound of another animal (n = 11), defecation or urination by a chimpanzee (n = 7), or unknown (n = 19). CVS bouts were longer when preceded by defecation or urination than when preceded by the vocalization or sound of other animals or an unknown factor. This suggests that the degree of wakefulness varies according to the possible cause of the disturbance. CVSs at night may be provoked by various factors, and awakening during the night is probably common among diurnal primates.