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Am J Primatol 2022 Jun 27:e23414. Epub 2022 Jun 27.

The Maderas Rainforest Conservancy, Miami, Florida, USA.

Maderas Rainforest Conservancy (MRC) is a conservation-focused non-profit organization that is devoted to protecting the tropical forests they manage in Costa Rica and Nicaragua and to providing conservation education for international university students through biological field schools. The MRC Primate Behavior and Ecology course is their most frequent course offering and is aimed at developing students to be independent field researchers. This course involves classroom lectures, training in primate identification and field methods, and the execution of independent research projects that students design, collect data for, and write up as scientific papers. Read More

Am J Primatol 2022 Jun 27:e23410. Epub 2022 Jun 27.

K. Lisa Yang Center for Conservation Bioacoustics, Cornell Lab of Ornithology, Cornell University, Ithaca, New York, USA.

Acoustic signals provide a model system for investigating the evolutionary processes that shape phenotypic diversity. Here we aim to investigate patterns of variation in tarsier duet phrases recorded from two mainland sites and eight offshore islands in North Sulawesi, Indonesia. We extracted features from the spectrograms of tarsier duet phrases and used a two-pronged approach to investigate patterns of variation in our data set. Read More

Am J Primatol 2022 Jun 27:e23411. Epub 2022 Jun 27.

Eco-anthropologie (EA), Muséum national d'Histoire naturelle, CNRS, Université Paris Cité, Paris, France.

Olfactory communication plays an important role in the regulation of socio-sexual interactions in mammals. There is growing evidence that both human and nonhuman primates rely on odors to inform their mating decisions. Nevertheless, studies of primate chemical ecology remain scarce due to the difficulty of obtaining and analyzing samples. Read More

Am J Primatol 2022 Jun 14:e23413. Epub 2022 Jun 14.

Institute for Society and Genetics, University of California Los Angeles, Los Angeles, California, USA.

Robust capuchin monkeys (Sapajus spp.) are distributed widely in the Neotropics and may be able to survive in modified landscapes because of their omnivorous, opportunistic diet. The poorly known and endangered crested capuchin monkey (Sapajus robustus) is endemic to the Atlantic Forest in Bahia, Minas Gerais and Espírito Santo states, Brazil. Read More

Am J Primatol 2022 Jun 14:e23397. Epub 2022 Jun 14.

Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia.

The role of plant secondary metabolites (PSMs) in shaping the feeding decisions, habitat suitability, and reproductive success of herbivorous mammals has been a major theme in ecology for decades. Although primatologists were among the first to test these ideas, studies of PSMs in the feeding ecology of non-human primates have lagged in recent years, leading to a recent call for primatologists to reconnect with phytochemists to advance our understanding of the primate nutrition. To further this case, we present a formal meta-analysis of diet choice in response to PSMs based on field studies on wild primates. Read More

Am J Primatol 2022 Jun 6:e23396. Epub 2022 Jun 6.

Programa de Pós-graduação em Biodiversidade Neotropical, Instituto Latino-Americano de Ciências da Vida e da Natureza, Universidade Federal da Integração Latino-Americana (UNILA), Foz do Iguaçu, Paraná, Brazil.

Capuchins are omnivorous neotropical primates that can survive in urban forests by supplementing their diet with human foods. However, few studies have analyzed the impact of these resources on their diet diversity and feeding seasonality. We aimed to assess the patterns of foraging, feeding, and diet diversity of urban capuchins (Sapajus sp. Read More

Am J Primatol 2022 May 30:e23393. Epub 2022 May 30.

Department of Psychological & Brain Sciences, Johns Hopkins University, Baltimore, Maryland, USA.

Over the past decade, noninvasive, restraint-free eye-tracking research with primates has transformed our understanding of primate social cognition. The use of this technology with many primate species allows for the exploration and comparison of how these species attend to and understand social agents and interactions. The ability to compare and contrast the cognitive capacities of various primate species, including humans, provides insight into the evolutionary mechanisms and selective pressures that have likely shaped social cognition in similar and divergent ways across the primate order. Read More

Am J Primatol 2022 May 25:e23395. Epub 2022 May 25.

Department of Psychology, University of Lethbridge, Lethbridge, Alberta, Canada.

Previous research on Japanese macaques has shown that female-to-male mounting (FMM) is performed by some females as an exaggerated form of sexual solicitation that may occur in the context of high female competition for male mates. This supernormal courtship behavior functions to prompt subsequent male-to-female mounting. In this report, we focused on the male consort partners' responses to FMM. Read More

Am J Primatol 2022 May 25:e23392. Epub 2022 May 25.

Lab. of Human Evolution Studies, Graduate School of Science, Kyoto University, Kyoto, Japan.

In primates, social relationships with a high frequency of social grooming are referred to as "affiliate relationships," "friendship," "bonding," and are described as involving positive emotion. However, the psychological state during social grooming has not been fully understood. In this study, I focused on blinking as a behavior that reflects psychological state during grooming in Macaca fuscata, a nonhuman wild primate, and examined for the first time whether the blink rate reflects concentration on social grooming. Read More

Am J Primatol 2022 May 25:e23394. Epub 2022 May 25.

School of Life Sciences, Sun Yat-sen University, Guangzhou, China.

Adult males living in a one-male multi-female social group are expected to try to monopolize copulations with resident females to increase reproductive fitness. Gibbons have traditionally been described as living in monogamous groups, with the sole resident adult male assumed to sire all of the group's offspring. Here, we used microsatellite analyses and behavioral observations to examine rates of extra-group paternity (EGP) over 16 years in a population of crested gibbons (Nomascus concolor) that form stable and long-term one-male two-female social units. Read More

Am J Primatol 2022 May 16;84(4-5):e23391. Epub 2022 May 16.

Department of Social Sciences and Anthropology, University of Toronto Scarborough, Toronto, Ontario, Canada.

Am J Primatol 2022 May 13:e23390. Epub 2022 May 13.

Department of Surgery and Surgical Specializations, Unit of Human Anatomy and Embryology, University of Barcelona, Barcelona, Spain.

In the deltoid muscles of Pan troglodytes and Homo sapiens, we have analyzed the muscle architecture and the expression of the myosin heavy chain (MHC) isoforms. Our aim was to identify differences between the two species that could be related to their different uses of the upper limb. The deltoid muscle of six adult Pan troglodytes and six adult Homo sapiens were dissected. Read More

Am J Primatol 2022 May 6:e23387. Epub 2022 May 6.

La Timone Neuroscience Institute, CNRS and Aix-Marseille University, Marseille, France.

Categorization of vocal sounds apart from other sounds is one of the key abilities in human voice processing, but whether this ability is present in other animals, particularly nonhuman primates, remains unclear. In the present study, 25 socially housed Guinea baboons (Papio papio) were tested on a vocal/nonvocal categorization task using Go/Nogo paradigm implemented on freely accessible automated learning devices. Three individuals from the group successfully learned to sort Grunt vocalizations from nonvocal sounds, and they generalized to new stimuli from the two categories, indicating that some baboons have the ability to develop open-ended categories in the auditory domain. Read More

Am J Primatol 2022 May 6:e23388. Epub 2022 May 6.

School of Biological Sciences, Universiti Sains Malaysia, Pulau Pinang, Malaysia.

Small ape habitat throughout Malaysia is rapidly being lost, degraded, and fragmented, and the effects of these changes on the abundance on this taxon are currently unknown. This study assessed the group density of Hylobates agilis in virgin forest, previously logged forest (1960s-1990s), and recently logged forest (2015-2017) of the Ulu Muda Forest Reserve (UMFR), Kedah, Malaysia. We conducted fixed-point active acoustic triangulation at nine survey areas to estimate group density. Read More

Am J Primatol 2022 Apr 29:e23386. Epub 2022 Apr 29.

Division of the Social Sciences, University of Chicago, Chicago, Illinois, USA.

An animal's welfare state is directly influenced by the mental state, which is shaped by experiences within the environment throughout the animal's life. For zoo-housed animals, visitors to the zoo are a large part of that environment and a fluctuating influence within it. This study examines the impact of zoo visitors on the space use of five species of zoo-housed primates (Eastern black-and-white colobus monkeys, Colobus guereza, n = 5, Allen's swamp monkeys, Allenopithecus nigroviridis, n = 2, DeBrazza's monkeys, Cercopithecus neglectus, n = 3, Bolivian gray titi monkeys, Callicebus donacophilus, n = 3, and crowned lemurs, Eulemur coronatus, n = 3). Read More

Am J Primatol 2022 Apr 22:e23385. Epub 2022 Apr 22.

Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.

Primatological research in zoos is increasing globally. Such research allows scientists to study primate biology, behavior, and cognition while helping to advance the welfare of captive primates. Moreover, zoos welcome millions of visitors annually, which creates unique opportunities for public engagement with this research. Read More

Am J Primatol 2022 Apr 13:e23383. Epub 2022 Apr 13.

Eco-anthropologie (EA), Muséum National d'Histoire Naturelle, CNRS, Université de Paris, Paris, France.

Comparative behavioral studies of hand use amongst primate species, including humans, have been central in research on evolutionary mechanisms. In particular, the manipulative abilities of our closest relatives, the chimpanzee (Pan troglodytes), have been widely described in various contexts, showing a high level of dexterity both in zoo and in natural conditions. In contrast, the study of bonobos' manipulative abilities has almost exclusively been carried out in experimental contexts related to tool use. Read More

Am J Primatol 2022 Apr 13:e23377. Epub 2022 Apr 13.

Primate Behavioral Ecology Lab, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, México.

Anthropogenic noise is increasingly disturbing natural soundscapes and affecting the physiology, behavior, and fitness of wildlife. However, our knowledge about the impact of anthropogenic noise on wild primates is scant. Here, we assess the effects of anthropogenic noise on the behavior of male mantled howler monkeys (Alouatta palliata). Read More

Am J Primatol 2022 Apr 7:e23381. Epub 2022 Apr 7.

Departamento de Zoologia, Setor de Ciências Biológicas, Universidade Federal do Paraná (UFPR), Curitiba, Brazil.

In primates, urine washing (UW) is a behavior in which individuals intentionally deposit urine on their bodies. Social and nonsocial hypotheses have been proposed to explain the adaptive function of this behavior. For capuchins, different functions have been assigned for UW, suggesting it as a flexible behavior, but studies have been mainly in captivity. Read More

Am J Primatol 2022 May 7;84(4-5):e23379. Epub 2022 Apr 7.

Global Health Program, Smithsonian Conservation Biology Institute, Washington, District of Columbia, USA.

Infectious diseases have the potential to extirpate populations of great apes. As the interface between humans and great apes expands, zoonoses pose an increasingly severe threat to already endangered great ape populations. Despite recognition of the threat posed by human pathogens to great apes, health monitoring is only conducted for a small fraction of the world's wild great apes (and mostly those that are habituated) meaning that outbreaks of disease often go unrecognized and therefore unmitigated. Read More

Am J Primatol 2022 Apr 7:e23384. Epub 2022 Apr 7.

Department of Anthropology, Washington University, St. Louis, Missouri, USA.

Whether the Colobus angolensis that reside in the fragmented forests in eastern Kenya and Tanzania represent one subspecies or two has been debated for 50 years. Morphological and more recent genetic and ecological studies suggest that these populations represent two subspecies, C. a. Read More

Am J Primatol 2022 May 5;84(4-5):e23376. Epub 2022 Apr 5.

Department of Infectious Diseases, Dermatology, Diagnostic Imaging and Radiotherapy, Medical School, São Paulo State University (Unesp), Botucatu, Brazil.

Wild nonhuman primates (NHP) are considered natural hosts of a protozoan parasite from the genus Leishmania, the etiological agent of leishmaniasis. It is important to study the population of this infectious agent in zoo animals to establish surveillance and control mechanisms in Sorocaba through the application of a One Health approach, this is where human-animal-environment health and disease interface and can aid in the protection of endangered species. This study aimed to identify Leishmania infantum and Leishmania braziliensis in NHP living in a city where leishmaniasis is endemic. Read More

Am J Primatol 2022 Apr 5:e23380. Epub 2022 Apr 5.

Population and Behavioral Health Services, California National Primate Research Center, University of California, Davis, California, USA.

Across captive settings, nonhuman primates may develop an array of abnormal behaviors including stereotypic and self-injurious behavior. Abnormal behavior can indicate a state of poor welfare, since it is often associated with a suboptimal environment. However, this may not always be the case as some behaviors can develop independently of any psychological distress, be triggered in environments known to promote welfare, and be part of an animal's coping mechanism. Read More

Am J Primatol 2022 Apr 5:e23382. Epub 2022 Apr 5.

Department of Anthropology, University of Zürich, Zürich, Switzerland.

Chimpanzees live in fission-fusion social organizations, which means that party size, composition, and spatial distribution are constantly in flux. Moreover, chimpanzees use a remarkably extensive repertoire of vocal and nonvocal forms of communication, thought to help convey information in such a socially and spatially dynamic setting. One proposed form of nonvocal communication in chimpanzees is buttress drumming, in which an individual hits a tree buttress with its hands and/or feet, thereby producing a low-frequency acoustic signal. Read More

Am J Primatol 2022 Apr 1:e23378. Epub 2022 Apr 1.

Division of Veterinary Resources, Office of Research Services, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.

The social setting of animal subjects in the research environment has known effects on a variety of dependent measures used in biomedical research. Proper evaluation of the robustness of published research is dependent upon transparent, detailed, and accurate reporting of research methods, including the animals' social housing conditions. However, to date, most research articles utilizing nonhuman primates (NHPs) provide only partial data on this topic, hampering transparency, and reproducibility. Read More

Am J Primatol 2022 Mar 24:e23374. Epub 2022 Mar 24.

Neuroscience and Behavior Unit, California National Primate Research Center, University of California, Davis, California, USA.

Temperament is a construct whose manifestations are quantifiable from an early age, and whose origins have been proposed as "biological." Our goal was to determine whether maternal rank and infant genotype are associated with five measures of temperament in 3- to 4-month old rhesus monkeys (Macaca mulatta), all of whom were born and reared by their mothers in large, outdoor, half-acre cages. Maternal rank was defined as the proportion of animals outranked by each female, and the two genes of interest to us were monoamine oxidase and serotonin transporter, both of which are polymorphic in their promoter regions (MAOA-LPR and 5-HTTLPR, respectively), with one allele of each gene considered a "plasticity" allele, conferring increased sensitivity to environmental events. Read More

Am J Primatol 2022 Mar 24:e23375. Epub 2022 Mar 24.

Department of Research & Conservation, Parco Natura Viva, Bussolengo, Italy.

The current research focuses on color preference between red and green stimuli and manual laterality in the emperor tamarin (Saguinus imperator). Trichromacy in primates has been related to a foraging advantage allowing frugivore primates to distinguish ripe from unripe fruits as well to socio-sexual communication, as trichromats would be advantaged in recognizing social and sexual signals. As warm colors can affect the emotive state of the subjects, leading to the activation of one hemisphere over the other (e. Read More

Am J Primatol 2022 Mar 21:e23373. Epub 2022 Mar 21.

Instituto de Neuroetologia, Universidad Veracruzana, Xalapa, Mexico.

Self-directed behavior, such as self-scratching (hereafter, scratching), occurs in several taxa across the animal kingdom, including nonhuman primates. There is substantial evidence that scratching is an indicator of anxiety-like emotions in a variety of nonhuman primate species. Despite its importance as a window into emotional states, few studies have investigated scratching in Platyrrhines. Read More

Am J Primatol 2022 May 16;84(4-5):e23370. Epub 2022 Mar 16.

Department of Applied Research, Wildlife Conservation Center, Zoo Park of São Paulo Foundation, São Paulo, Brazil.

The black lion tamarin (Leontopithecus chrysopygus) is an endangered primate species, restricted to the Atlantic Forest fragments of São Paulo state, Brazil, with an estimated wild population of ~1600 individuals. Integrative studies between zoo (ex situ) and wild (in situ) animals are crucial to modern conservation programs. They can demonstrate a substantial impact with the One Health concept, an interdisciplinary research frontier regarding the relations between human, animal, and environmental health. Read More

Am J Primatol 2022 Mar 14:e23369. Epub 2022 Mar 14.

School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK.

Primate cognition research is reliant on access to members of the study sp ecies and logistical infrastructures to conduct observations and experiments. Historically founded in research centers and private collections, and spreading to modern zoos, sanctuaries, and the field, primate cognition has been investigated in diverse settings, each with benefits and challenges. In our systematic review of 12 primatology, animal behavior, and animal cognition journals over the last 15 years, we turn a spotlight on zoos to quantify their current impact on the field and to highlight their potential as robust contributors to future work. Read More