A variety of studies show that parental absence early in life leads to deleterious effects on the developing CNS. This is thought to be largely because evolutionary-dependent stimuli are necessary for the appropriate postnatal development of the young brain, an effect sometimes termed the “experience-expectant brain,” with parents providing the necessary input for normative synaptic connections to develop and appropriate neuronal survival to occur. Principal among CNS systems affected by parental input are the monoamine systems. In the present study,N= 434 (...) rhesus monkeys (233 males, 201 females) were reared in one of two conditions: as mother-reared controls (MR;n= 269) or without adults with 24-h access to same-aged peers (PR;n= 165). When subjects were six-months-old, they underwent a separation paradigm involving 4, sequential, four-day social separations from their mothers or peers, with each separation followed by three-day reunions with their mothers or their peers. Prior to the separation paradigm, baseline cisternal CSF samples were obtained, as well as at the end of each the four social separations, and after final separation, during a recovery period. CSF was assayed for concentrations of monoamine metabolites and a blood sample was genotyped for the serotonin transporter (5-HTT) genotype. Replicating earlier landmark findings, PR subjects with thesallele exhibited lower baseline concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA), when compared to PR subjects homozygous for theLallele. MR subjects were undifferentiated by genotype. PR subjects exhibited lower CSF 5-HIAA concentrations during baseline, but higher CSF 5-HIAA during social separations, when compared to MR subjects. There were rearing effects for the dopamine metabolite homovanillic acid (HVA) and for the norepinephrine metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG), with PR subjects showing higher HVA and lower MHPG when compared to MR subjects. These findings indicate that there are long-term deficits in the response of monoamines following early maternal absence. The results of this study confirm and extend earlier findings that early parental absence has deleterious consequences for the development of the monoamine systems, and that these consequences are modulated by the 5-HTT genotype. (shrink)

The human “environment of evolutionary adaptedness” can only be inferred indirectly. In contrast, the behavior of some nonhuman animals can be compared among “natural” and various altered environments. As an example, male immigration tactics in unprovisioned versus provisioned macaque (Macaca) populations are compared using Tooby and Cosmides’s (1992) framework for evolutionary functional analysis. In unprovisioned populations, social groups contain few males, and immigrant male takeovers of alpha rank occur frequently. In provisioned populations, groups contain many males, and males almost (...) invariably enter social groups at very low rank and rise in rank only as more dominant males emigrate or die. Male conformity to the “seniority rule” is hypothesized to represent the behavioral output of an evolved decision-making algorithm (psychological mechanism) that takes into account (1) the net payoff of each rank in the dominance hierarchy and (2) the power of male group size as a predictor of the likelihood of successful immigrant takeover. (shrink)

Infanticide is one of the typical examples used in many general evolutionary hypothesis on vertebrate evolution especially those based on sociobiology. We have shown that this phenomenon is very complicated and in no case can be interpreted as a support for sociobiological ideas. It is not so common a phenomenon in the primate societies as sociologists claim, and even in the “typical” primate species as anhuman langurs, has a very limited and different meaning. Furthermore, there are a lot of examples (...) where many sociobiological hypothesis are based on very superficial and overgeneralized interpretations of nonhuman primate infanticide. In human populations infanticide is usually connected with the cases when the carrying capacity of an ecosystem is no longer sufficient for the survival of a population. It is a conscious action based on longterm empirical knowledge. No negative emotions of even aggressiveness connected with infanticide is know in human groups. We try to demonstrate that the research of primate infanticide gives no consistent basis for its generalization in the framework of sociobiological hypothesis and in evolutionary theories in general. (shrink)

The long-tailed macaque (Macaca fascicularis fascicularis) is a non-human primate species that is native to Singapore. From mid-2020, the Nanyang Technological University campus witnessed a sharp increase in the number of human–macaque encounters. In this article, we will first identify a set of technological tools that we have developed to guide decision- and policy-making on the wildlife management front and mitigate human–macaque conflict. Thereafter, we will describe how we applied these tools to the activity log cataloguing the macaque activity (...) on campus and offer an analysis of the trends in macaque behaviour that may be shared with members of the public and affected residents. Among the results that will be discussed are the following: a significant decline in the number of macaque sightings at Student Residences over the weekend, a majority of the reported macaque sightings occurring in the early evening, no significant difference in the damage and proximity scores over time, and a trend in observed macaque activity at critical sleep-relevant time intervals and areas on campus. We hope that our approach will promote, through an improved and data-driven understanding of macaque behavioural trends, technology-assisted decision-making and a more harmonious co-existence between humans and macaques on campus and in Singapore. Last but not least, we anticipate further extensions of our approach with respect to other forms of wildlife. (shrink)

The long-tailed macaque (Macaca fascicularis fascicularis) is a non-human primate species that is native to Singapore. From mid-2020, the Nanyang Technological University campus witnessed a sharp increase in the number of human–macaque encounters. In this article, we will first identify a set of technological tools that we have developed to guide decision- and policy-making on the wildlife management front and mitigate human–macaque conflict. Thereafter, we will describe how we applied these tools to the activity log cataloguing the macaque activity (...) on campus and offer an analysis of the trends in macaque behaviour that may be shared with members of the public and affected residents. Among the results that will be discussed are the following: a significant decline in the number of macaque sightings at Student Residences over the weekend, a majority of the reported macaque sightings occurring in the early evening, no significant difference in the damage and proximity scores over time, and a trend in observed macaque activity at critical sleep-relevant time intervals and areas on campus. We hope that our approach will promote, through an improved and data-driven understanding of macaque behavioural trends, technology-assisted decision-making and a more harmonious co-existence between humans and macaques on campus and in Singapore. Last but not least, we anticipate further extensions of our approach with respect to other forms of wildlife. (shrink)

Most evolutionary analyses of animal communication suggest that low-cost signals can evolve only when both the signaller and the recipient rank outcomes in the same order. When there is a conflict of interest between sender and receiver, honest signals must be costly. However, recent work suggests that low-cost signals can be evolutionarily stable, even when the sender and the receiver rank outcomes in different orders, as long as the interest in achieving coordination is sufficiently great. In this paper, we extend (...) this body of work by analysing a game theory model that shows that low-cost signals can evolve when there are conflicts of interest and no interest in coordination, as long as individuals interact repeatedly. We also present an empirical example indicating that female rhesus macaques, Macaca mulatta, use honest, low-cost, vocal signals to facilitate interactions when conflicts of interest exist. (shrink)

For vocal animals, recognizing species-specific vocalizations is important for survival and social interactions. In humans, a voice region has been identified that is sensitive to human voices and vocalizations. As this region also strongly responds to speech, it is unclear whether it is tightly associated with linguistic processing and is thus unique to humans. Using functional magnetic resonance imaging of macaque monkeys (Old World primates, Macaca mulatta) we discovered a high-level auditory region that prefers species-specific vocalizations over other vocalizations (...) and sounds. This region not only showed sensitivity to the ‘voice’ of the species, but also to the vocal identify of conspecific individuals. The monkey voice region is located on the superior-temporal plane and belongs to an anterior auditory ‘what’ pathway. These results establish functional relationships with the human voice region and support the notion that, for different primate species, the anterior temporal regions of the brain are adapted for.. (shrink)

Most evolutionary analyses of animal communication suggest that low-cost signals can evolve only when both the signaller and the recipient rank outcomes in the same order. When there is a conflict of interest between sender and receiver, honest signals must be costly. However, recent work suggests that low-cost signals can be evolutionarily stable, even when the sender and the receiver rank outcomes in different orders, as long as the interest in achieving coordination is sufficiently great. In this paper, we extend (...) this body of work by analysing a game theory model that shows that low-cost signals can evolve when there are conflicts of interest and no interest in coordination, as long as individuals interact repeatedly. We also present an empirical example indicating that female rhesus macaques, Macaca mulatta, use honest, low-cost, vocal signals to facilitate interactions when conflicts of interest exist. (shrink)

The effects of calorie restriction have now been studied in two non‐human primates, the macaque Macaca mulatta and the mouse lemur Microcebus murinus. The study on lemurs and one of the two studies on macaques have reported a lifespan increase. In this review, I argue that these results are better explained by a lifespan decrease in the control group because of a bad diet and/or overfeeding, rather than by a real lifespan increase in calorie‐restricted animals. If these results can (...) be readily translated to humans, it would mean that no beneficial effect of calorie restriction on lifespan can be expected in normal‐weight or lean people, but that overweight and/or obese people could benefit to some extent from a decrease in excessive food intake. (shrink)

Despite considerable evidence that neural activity in monkeys reflects various aspects of face perception, relatively little is known about monkeys’ face processing abilities. Two characteristics of face processing observed in humans are a subordinate-level entry point, here, the default recognition of faces at the subordinate, rather than basic, level of categorization, and holistic effects, i.e. perception of facial displays as an integrated whole. The present study used an adaptation paradigm to test whether untrained rhesus macaques (Macaca mulatta) display these (...) hallmarks of face processing. In experiments 1 and 2, macaques showed greater rebound from adaptation to conspecific faces than to other animals at the individual or subordinate level. In experiment 3, exchanging only the bottom half of a monkey face produced greater rebound in aligned than in misaligned composites, indicating that for normal, aligned faces, the new bottom half may have influenced the perception of the whole face. Scan path analysis supported this assertion: during rebound, fixation to the unchanged eye region was renewed, but only for aligned stimuli. These experiments show that macaques naturally display the distinguishing characteristics of face processing seen in humans and provide the first clear demonstration that holistic information guides scan paths for conspecific faces. (shrink)

This paper presents the results of the Symposium on “Deforestation and reforestation: The Atlas Project”. From the studies presented appeared that at present the causes od deforestation do not arise so much from global climatic causes, but rather from human activity. Both the study conducted on the Nokopo population in Papua New Guinea, by Kocher Schmid, and the one conducted on the Berbers in Morocco, by Camperio Ciani and Arhou, presented a clear role of the local population and its tradition (...) on negatiove forerst iòpact. Agro-forestal grazing and clearing for domestic animal feeding produced heavy forest degeneration. In Morocco the role of mixed herds of a few goats with many sheep produce devastating effects to the undergrowth of the Cedar and Oak forest. While fires ang pig overgrazing produce deforestation in the Nokopo Primary forest region. Further the external impact of foreign culture negatively affects the dinamic relationship between the local culture and the forest environment. The desertification process that emerges is a bottom up one that begins from the undergrowth reduction and ends with tha actual felling of the tree. It is suggested that close monuitoring of the forest condition using biological indicators could be a useful inyegration to remote sensing methods. As an example Macaca sylvanus demography has proven an efficient biological indicator to individuate early forest desertification risks in Morocco. It is proposed the Atlas project that combines reforestation with an efficient monitoring system and the study and development of sustainable alternatives to overgrazing to reduce the desertification process of the last North Africa forest. (shrink)

This paper presents the results of the Symposium on “Deforestation and reforestation: The Atlas Project”. From the studies presented appeared that at present the causes od deforestation do not arise so much from global climatic causes, but rather from human activity. Both the study conducted on the Nokopo population in Papua New Guinea, by Kocher Schmid, and the one conducted on the Berbers in Morocco, by Camperio Ciani and Arhou, presented a clear role of the local population and its tradition (...) on negatiove forerst iòpact. Agro-forestal grazing and clearing for domestic animal feeding produced heavy forest degeneration. In Morocco the role of mixed herds of a few goats with many sheep produce devastating effects to the undergrowth of the Cedar and Oak forest. While fires ang pig overgrazing produce deforestation in the Nokopo Primary forest region. Further the external impact of foreign culture negatively affects the dinamic relationship between the local culture and the forest environment. The desertification process that emerges is a bottom up one that begins from the undergrowth reduction and ends with tha actual felling of the tree. It is suggested that close monuitoring of the forest condition using biological indicators could be a useful inyegration to remote sensing methods. As an example Macaca sylvanus demography has proven an efficient biological indicator to individuate early forest desertification risks in Morocco. It is proposed the Atlas project that combines reforestation with an efficient monitoring system and the study and development of sustainable alternatives to overgrazing to reduce the desertification process of the last North Africa forest. (shrink)