The what and where of primate field research may be failing primate conservation

Behavioral thermoregulation in primates: A review of literature and future avenues

Primates face severe challenges from climate change, with warming expected to increase animals' thermoregulatory demands. Primates have limited long-term options to cope with climate change, but possess a remarkable capacity for behavioral plasticity. This creates an urgency to better understand the behavioral mechanisms primates use to thermoregulate. While considerable information exists on primate behavioral thermoregulation, it is often scattered in the literature in a manner that is difficult to integrate. This review evaluates the status of the available literature on primate behavioral thermoregulation to facilitate future research. We surveyed peer-reviewed publications on primate thermoregulation for N = 17 behaviors across four thermoregulatory categories: activity budgeting, microhabitat use, body positioning, and evaporative cooling. We recorded data on the primate taxa evaluated, support for a thermoregulatory function, thermal variable assessed, and naturalistic/manipulative study conditions. Behavioral thermoregulation was pervasive across primates, with N = 721 cases of thermoregulatory behaviors identified across N = 284 published studies. Most genera were known to utilize multiple behaviors (x ¯  = 4.5 ± 3.1 behaviors/genera). Activity budgeting behaviors were the most commonly encountered category in the literature (54.5% of cases), while evaporative cooling behaviors were the least represented (6.9% of cases). Behavioral thermoregulation studies were underrepresented for certain taxonomic groups, including lemurs, lorises, galagos, and Central/South American primates, and there were large within-taxa disparities in representation of genera. Support for a thermoregulatory function was consistently high across all behaviors, spanning both hot- and cold-avoidance strategies. This review reveals asymmetries in the current literature and avenues for future research. Increased knowledge of the impact thermoregulatory behaviors have on biologically relevant outcomes is needed to better assess primate responses to warming environments and develop early indicators of thermal stress.

Mentorship and professional growth for conservationists in primate-range countries

Ways to support professional capacity of emerging conservation leadership in primate range countries.

Intrageneric taxonomic distinction based on morphological variation in the macaque (Macaca) skeleton

Taxonomic classification is important for understanding the natural world, yet current methods for species assessment often focus on craniodental morphology rather than the entire skeleton. Moreover, it is currently unknown how much variation could, or should, exist intragenerically. Here, we tested whether taxonomy can be accurately predicted based on patterns of morphological variation in macaques (H1 ) and whether postcranial bones reflect subgeneric macaque taxonomy similarly, or better, than the cranium (H2 ). Data included 3D scans of cranial and postcranial bones for eight macaque species (Macaca arctoides, Macaca fascicularis, Macaca fuscata, Macaca mulatta, Macaca nemestrina, Macaca nigra, Macaca radiata, and Macaca sylvanus). Fixed anatomical and semilandmarks were applied to scans of eight skeletal elements (crania = 45; mandible = 31; scapula = 66; humerus = 38; radius = 33; os coxa = 28; femur = 40; tibia = 40). For each skeletal element, regression analyses were performed to minimize the effects of sexual dimorphism. Between-groups principal components analysis was used to visualize the major patterns of among-species morphological variation, while the strength of correct taxon classification was measured with discriminant function analysis. Results suggested accepting the alternate hypothesis that different macaque species can be distinguished morphologically. Both cranial and many postcranial elements appeared to possess a taxonomic signal, and the limb bones-especially the upper limb-are reported to be more useful for taxonomic assessment than previously realized. Theoretically, certain behaviors and/or ecogeographical factors, as well as phylogeny, influenced skeletal morphology in macaques, likely contributing to taxonomic distinctions among different species.

Primates and disability: Behavioral flexibility and implications for resilience to environmental change

Congenital malformations, conditions, injuries, and illness can lead to long-term physical impairment and disability in nonhuman primates. How individual primates change their behaviors flexibly to compensate for their disabilities can inform our understanding of their resilience and ability to adjust to environmental change. Here, we synthesize the literature on nonhuman primates and disability, addressing the questions: how does disability influence behavior in primates? What insights can we take from the literature to better understand and predict the capacity of primates to modify their behaviors in the face of human-induced environmental change? We conducted a systematic review of the literature on spontaneous physical impairment and disability in captive, free-ranging, and wild primates. We surveyed 2807 articles on Web of Science and Scopus and identified 114 studies that fit our predetermined inclusion criteria. Behavioral plasticity, maternal and conspecific care, and the potential for innovation of novel behaviors allow many primates with disabilities to compensate when faced with challenges that are outside the scope of usual circumstances. We also found that 60% of the publications connected primate physical impairment and disability to human activities, suggesting an entangled relationship among humans, the environment, and primate disability. Disability and physical impairments provide an opportunity to examine how primates modify their behavior when presented with challenging conditions, and their potential resilience to a changing environment.

Primate field research during a pandemic: Lessons learned from the SARS-CoV-2 outbreak

The COVID-19 pandemic abruptly halted most primate field research in early 2020. While international travel bans and regional travel restrictions made continuing primate field research impossible early on in the pandemic, ethical concerns of transmitting the virus from researchers to primates and surrounding human communities informed decisions regarding the timing of resuming research. Between June and September 2020, we surveyed field primatologists regarding the impacts of the pandemic on their research. We received 90 completed surveys from respondents residing in 21 countries, though most were from the United States and Canada. These data provide a valuable window into the perspectives and actions taken by researchers during the early stages of the pandemic as events were still unfolding. Only 2.4% of projects reported continuing research as usual, 33.7% continued with some decrease in productivity, 42.2% reported postponing research projects, and 21.7% reported canceling projects or postponing research indefinitely. Respondents most severely impacted by the pandemic were those establishing new field sites and graduate students whose projects were postponed or canceled due to pandemic-related shutdowns. Fears about increased poaching, the inability to pay local assistants, frozen research funds, declining habituation, disruptions to data collection, and delays in student projects were among the top concerns of respondents. Nearly all the projects able to continue research in any capacity during the early months of the pandemic were run by or employed primate habitat country primatologists. This finding is a major lesson learned from the pandemic; without habitat country scientists, primate research is not sustainable.

Path To Acceptance and Refined Practices for Habituating Western Lowland Gorillas

Although western lowland gorillas (Gorilla gorilla gorilla) are the most numerous and widespread gorilla subspecies, they have remained relatively unstudied. International tourism has been initiated at several sites in the Congo Basin, which necessitates habituation of gorillas to human presence. However, habituation has proven difficult due to several obstacles, including relatively low population densities, small group sizes, and thick understory vegetation. In this article, we propose refinements to current approaches to habituating western lowland gorillas that maximize safety and emphasize adaptive responses based on empirical evidence. In addition to reviewing published reports, our approach is informed by the recent habituation of the Mététélé group in the Djéké Triangle, an area that was recently included in the Nouabalé-Ndoki National Park in Republic of Congo. We evaluate progress in habituation according to time spent in the presence of the gorillas and their reactions to humans. The Mététélé group is composed of 14 individuals and has a home range that overlaps with two habituated gorilla groups. Early in the habituation process, we discovered that three of Mététélé's group members were individuals who had previously been habituated as members of other groups. The presence of these individuals expedited the habituation process. Familiarity with humans may have also reduced aggressive responses during the habituation process. The overall result is a refined step-by-step approach to the habituation of western lowland gorillas that includes procedures and assessments to meet best-practice guidelines and ensure the wellbeing of both gorillas and humans.

Road Infrastructure and Primate Conservation: Introducing the Global Primate Roadkill Database

As road infrastructure networks rapidly expand globally, especially in the tropics, previously continuous habitats are being fragmented, resulting in more frequent wildlife-vehicle collisions (WVC). Primates are widespread throughout many sub-/tropical countries, and as their habitats are fragmented, they are increasingly at risk of WVC. We created the Global Primate Roadkill Database (GPRD), the largest available standardized database of primate roadkill incidents. We obtained data from published papers, un-published and citizen science databases, anecdotal reports, news reports, and social media posts. Here, we describe the collection methods for the GPRD and present the most up-to-date version of the database in full. For each primate roadkill incident, we recorded the species killed, the exact location, and the year and month the roadkill was observed. At the time of publication, the GPRD includes 2862 individual primate roadkill records from 41 countries. As primates range in more than twice as many countries, the absence of data from these countries is not necessarily indicative of a lack of primate vehicular collisions. Given the value of these data for addressing both local and global research questions, we encourage conservationists and citizen scientists to contribute to the GPRD so that, together, we can better understand the impact road infrastructure has on primates and evaluate measures which may help mitigate risk-prone areas or species.

Mental health and well-being in primatology: Breaking the taboos

We hope to raise awareness of mental health and well-being among primatologists. With this aim in mind, we organized a workshop on mental health as part of the main program of the Winter meeting of the Primate Society of Great Britain in December 2021. The workshop was very well received. Here, we review the main issues raised in the workshop, and supplement them with our own observations, reflections, and reading. The information we gathered during the workshop reveals clear hazards to mental health and suggests that we must collectively acknowledge and better manage both the hazards themselves and our ability to cope with them if we are to avert disaster. We call on institutions and learned societies to lead in seeking solutions for the benefit of primatologists and primatology.

Turn-taking skills in mammals: A systematic review into development and acquisition

How human language evolved remains one of the most intriguing questions in science, and different approaches have been used to tackle this question. A recent hypothesis, the Interaction Engine Hypothesis, postulates that language was made possible through the special capacity for social interaction involving different social cognitive skills (e.g., joint attention, common ground) and specific characteristics such as face-to-face interaction, mutual gaze and turn-taking, the exchange of rapid communicative turns. Recently, it has been argued that this turn-taking infrastructure may be a foundational and ancient mechanism of the layered system of language because communicative turn-taking has been found in human infants and across several non-human primate species. Moreover, there is some evidence for turn-taking in different mammalian taxa, especially those capable of vocal learning. Surprisingly, however, the existing studies have mainly focused on turn-taking production of adult individuals, while little is known about its emergence and development in young individuals. Hence, the aim of the current paper was 2-fold: First, we carried out a systematic review of turn-taking development and acquisition in mammals to evaluate possible research bias and existing gaps. Second, we highlight research avenues to spur more research into this domain and investigate if distinct turn-taking elements can be found in other non-human animal species. Since mammals exhibit an extended development period, including learning and strong parental care, they represent an excellent model group in which to investigate the acquisition and development of turn-taking abilities. We performed a systematic review including a wide range of terms and found 21 studies presenting findings on turn-taking abilities in infants and juveniles. Most of these studies were from the last decade, showing an increased interest in this field over the years. Overall, we found a considerable variation in the terminologies and methodological approaches used. In addition, studies investigating turn-taking abilities across different development periods and in relation to different social partners were very rare, thereby hampering direct, systematic comparisons within and across species. Nonetheless, the results of some studies suggested that specific turn-taking elements are innate, while others are acquired during development (e.g., flexibility). Finally, we pinpoint fruitful research avenues and hypotheses to move the field of turn-taking development forward and improve our understanding of the impact of turn-taking on language evolution.

Establishing the relationship between non-human primates and mangrove forests at the global, national, and local scales

Global and spatially explicit information about the interaction between habitat and wildlife species is critical to enhancing conservation efforts. Despite the recognized importance of mangrove forests to non-human primates, the relationship between the two lacks understanding. To counter this, we created the MangPrim-21 database to map and measure the locations of interactions between all non-human primates and all mangrove forests globally. We report our findings across the global, national, and local scales for all inventoried non-human primates and all inventoried mangrove forests. Globally, we find that half of all non-primates potentially use mangrove forests, and more than half of the global mangrove forest falls within the delineated range of at least one non-human primate species. Nationally, we find that Indonesia, Madagascar, Brazil, Cameroon, and Malaysia likely have the most non-human primate and mangrove forest interactions. At the subnational level, we find that several discrete locations in Kalimantan are critical to both mangrove forests and non-human primates. The MangPrim-21 database provides a globally consistent and locally applicable database of non-human primate and mangrove forest interactions. The results presented have broader implications for non-human primate and mangrove conservation and global actions to protect both. Additionally, our results raise questions about the idea that non-human primates primarily use mangrove forests as a refuge from human encroachment and habitat degradation.

Best practices are never best: Evaluating primate conservation education programs (PCEPs) with a decolonial perspective

Who do we aim to educate with primate conservation education programs (PCEPs)? In a commentary published in a recent AJP, Annette Lanjouw suggested that many efforts to "educate" habitat-country communities can be neocolonial in their approaches. Forest destruction and habitat loss are a result of global consumption and expansion. We therefore need to approach conservation education from many angles including local stakeholders, policy makers, government officials, and the humans living in industrialized nations who are major consumers of the items that shrink primate habitats. In this review, we investigate PCEPs to determine if the conservation education goals, education methods, and assessment processes are proceeding within a neocolonial context. We reviewed the last 20 years of primate conservation literature and looked for publications that were focused on education programs. We found that in 50 of 52 publications published between 2001 and 2021, the education programs take place in habitat-country local communities. We also reviewed primate field researcher and field site websites, and in most cases, education programs were also focused on educating local communities living near or in nonhuman primate habitats. Exceptions were student clubs, zoo programs, and a high school outreach program. Many PCEP providers presented a list of "lessons learned" and we compiled their wisdom in combination with our experience to provide a framework for moving forward. We conclude that as conservation primatologists, we must think beyond our field sites to create opportunities for educational outreach. We can reach global consumers by linking to zoos, television/motion picture, print media, social media, and working with schools on curricula. Primatologists can engage our undergraduates to establish clubs and create meaningful assignments that reach beyond the classroom. We encourage primatologists from the Global North to consider their positionality and the history of conservation exclusion in their attempts to conserve primates.

Student research collaboration as conservation education: A case study from the primate field school at Maderas Rainforest Conservancy

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. Student development as conservationists is facilitated through the research experience provided by this field course as well as through co- and extracurricular research opportunities available to students at the sites that MRC manages: La Suerte Biological Research Station in Costa Rica, and Ometepe Biological Research Station in Nicaragua. In tandem with their participation in the MRC primate field course, we (Laura M. Bolt and Amy L. Schreier) consistently offer students research opportunities in our ongoing project examining the impact of forest fragmentation on primate behavioral ecology. MRC student course evaluations indicate that this co- and extracurricular research participation substantially contributes to student academic development and conservation awareness. Student research collaboration, therefore, greatly benefits students as well as furthers MRC's conservation goals as a non-profit organization. In future MRC primate field school sessions, we will continue to offer research collaboration opportunities to students and will also endeavor to improve conservation education at MRC by involving more local community members in MRC's academic programs.

Landscapes of Time: Building Long-Term Perspectives in Animal Behavior

In the 1960s, scientists fascinated by the behavior of free-living animals founded research projects that expanded into multi-generation investigations. This paper charts the history of three scientists' projects to uncover the varied reasons for investing in a "long-term" perspective when studying animal behavior: Kenneth Armitage's study of marmots in the Rocky Mountains, Jeanne Altmann's analysis of baboons in Kenya, and Timothy Hugh Clutton-Brock's studies (among others) of red deer on the island of Rhum and meerkats in the Kalahari. The desire to study the behavior of the same group of animals over extended periods of time, I argue, came from different methodological traditions - population biology, primatology, and sociobiology - even as each saw themselves as contributing to the legacy of ethology. As scientists embraced and combined these approaches, a small number of long-running behavioral ecology projects like these grew from short pilot projects into decades-long centers of intellectual gravity within behavioral ecology as a discipline. By attending to time as well as place, we can see how this long-term perspective was crucial to their success; they measured evolutionary changes over generations of animals and their data provided insights into how the animals they studied were adapting (or not) to changing local and global environmental factors.

Impact of the COVID-19 Pandemic on Primate Research and Conservation

Simple Summary

The Coronavirus Disease 2019 (COVID-19) pandemic has made it harder to effectively protect and manage biodiversity, and this could make it more difficult for countries to show progress towards the Sustainable Development Goals (SDGs). Here, we surveyed experts in early 2022 from 30 countries to collect data on the impacts of COVID-19 on non-human primate research and conservation initiatives. Of the 93 experts that responded to our survey, we found that 39% had not been able to visit any of their field sites since March 2020 and only one out of ten had managed to achieve at least 76–100% of their planned primate-related work since March 2020. Six out of ten respondents (61%) felt that primate conservation efforts in protected areas were worse than before the onset of the COVID-19 pandemic and one-third (33%) felt hunting was happening more frequently than before. This study provides evidence of the impacts of COVID-19 on progress towards achieving SDG15 (Life on Land) and provides practical lessons learned for biodiversity conservation efforts moving forward.

Abstract

There is evidence to suggest that the Coronavirus Disease 2019 (COVID-19) pandemic may hamper our achievement of the Sustainable Development Goals (SDGs). Here, we use non-human primates as a case study to examine the impacts of COVID-19 on the ability to achieve biodiversity conservation and management sustainability targets. We collected data through a survey of members of the IUCN SSC Primate Specialist Group from January to March 2022. Of the 93 experts that responded to our survey, we found that 39% had not been able to visit any of their field sites since March 2020, 54% said they had less funding available for their primate-related work, and only one out of ten said they had managed to achieve at least 76–100% of their planned primate-related work since March 2020. Six out of ten respondents (61%) felt that primate conservation efforts in protected areas were worse than before the onset of the COVID-19 pandemic and one-third (33%) felt hunting was happening more frequently than before. This study provides evidence of the impacts of COVID-19 on progress towards achieving the SDGs, and provides practical lessons learned for biodiversity conservation efforts moving forward.

The role of lemur seed dispersal in restoring degraded forest ecosystems in Madagascar

Anthropogenic disturbances lead to the degradation or destruction of tropical forests, with negative consequences for flora, fauna, and local people. Restoration plantings may compensate these impacts, but time and financial expenditures are high. Thus, priority is often given to plantations of a few introduced species that have little value for conservation. Animal seed dispersal may diversify and accelerate regeneration of restoration plantings, thereby lowering their costs. We studied seed dispersal quantity and quality of crowned lemurs (Eulemur coronatus) in a highly degraded forest in northern Madagascar, conducting behavioural observations and germination experiments and describing dispersed plant species’ characteristics. Crowned lemurs were highly frugivorous, dispersing a large number of seeds and plant species. While there were negative effects of gut passage on germination, the positive effects of pulp removal outweighed these, resulting in an overall positive effect on regeneration. Our study confirmed that effects of gut passage are dependent on the dispersed plant species. We found 20 plant species, including three threatened with extinction, whose only dispersers in Oronjia seem to be crowned lemurs. We conclude that lemurs play important roles in protecting plant species and maintaining healthy ecosystems through seed dispersal, and that E. coronatus is a key species in this respect. In addition, if lemurs were included in restoration, they would disperse a diversity of plant species that cannot be matched by conventional restoration plantings. Their influence would facilitate the regeneration of some, but not all plant species. Negative effects, like the spread of invasive species through seed dispersal by lemurs, must also be considered.

Taxonomic and geographic bias in 50 years of research on the behaviour and ecology of galagids

Identifying knowledge gaps and taxonomic and geographic bias in the literature is invaluable for guiding research towards a more representative understanding of animal groups. Galagids are nocturnal African primates and, for many species, detailed information on their behaviour and ecology is unavailable. To identify gaps and bias in the literature we reviewed published peer-reviewed research articles on galagid behaviour and ecology over a 50-year period from January 1971 to December 2020. Using the Web of Science and Google Scholar databases, we identified 758 articles, assessed 339 full texts for eligibility and included 211 in the review. Species of Otolemur have been extensively researched in comparison to other genera (78.2% of studies; Euoticus: 13.3% of studies; Galago: 66.4% of studies; Galagoides: 20.9% of studies; Paragalago: 22.3% of studies; Sciurocheirus: 15.2% of studies). The most common category of research was physiology (55.0% of studies), followed by behavioural ecology (47.4% of studies), and fewer studies were on genetics and taxonomy (16.1% of studies) and habitat and distribution (14.2% of studies). Text mining revealed that the word 'behaviour' was the most common word used in abstracts and keywords, and few words were related to ecology. Negative binomial regression revealed that mean body mass and geographic range size were significant positive predictors of the total number of scientific outputs on each species. Research on wild populations was carried out in only 24 (60%) of the 40 countries galagids are thought to inhabit. Studies were undertaken in locations with lower mean annual temperatures and higher human population densities over warmer and less populated areas. We encourage a more equal sampling effort both taxonomically and geographically that in particular addresses the paucity of research on smaller species and those with restricted ranges. Research on in situ populations, especially in warmer and remote areas, is urgently needed, particularly in West, Central and some Southern African countries.

Why do some primate mothers carry their infant's corpse? A cross-species comparative study

Non-human primates respond to the death of a conspecific in diverse ways, some of which may present phylogenetic continuity with human thanatological responses. Of these responses, infant corpse carrying by mothers (ICC) is the most frequently reported. Despite its prevalence, quantitative analyses of this behaviour are scarce and inconclusive. We compiled a database of 409 published cases across 50 different primate species of mothers' responses to their infants' deaths and used Bayesian phylogenetic regressions with an information-theoretic approach to test hypotheses proposed to explain between- and within-species variation in ICC. We found that ICC was more likely when the infant's death was non-traumatic (e.g. illness) versus traumatic (e.g. infanticide), and when the mother was younger. These results support the death detection hypothesis, which proposes that ICC occurs when there are fewer contextual or sensory cues indicating death. Such an interpretation suggests that primates are able to attain an awareness of death. In addition, when carried, infant age affected ICC duration, with longer ICC observed for younger infants. This result suggests that ICC is a by-product of strong selection on maternal behaviour. The findings are discussed in the context of the evolution of emotion, and implications for evolutionary thanatology are proposed.

Integrative approaches to dispersing science: A case study of March Mammal Madness

OBJECTIVES

Public engagement is increasingly viewed as an important pillar of scientific scholarship. For early career and established scholars, navigating the mosaic landscape of public education and science communication, noted for rapid "ecological" succession, can be daunting. Moreover, academics are characterized by diverse skills, motivations, values, positionalities, and temperaments that may differentially incline individuals to particular public translation activities.

METHODS

Here we briefly contextualize engagement activities within a scholarly portfolio, describe the use of one public education program-March Mammal Madness (MMM)- to highlight approaches to science communication, and explore essential elements and practical considerations for creating and sustaining outreach pursuits in tandem with other scholarly activities.

RESULTS

MMM, an annual simulated tournament of living and fossil animal taxa, has reached hundreds of thousands of learners since 2013. This program has provided a platform to communicate research findings from biology and anthropology and showcase numerous scholars in these fields. MMM has leveraged tournament devices to intentionally address topics of climate change, capitalist environmental degradation, academic sexism, and racist settler-colonialism. The tournament, however, has also perpetuated implicit biases that need disrupting.

CONCLUSIONS

By embracing reflexive, self-interrogative, and growth attitudes, the tournament organizers iteratively refine and improve this public science education program to better align our activities with our values and goals. Our experiences with MMM suggest that dispersing science is most sustainable when we combine ancestral adaptations for cooperation, community, and storytelling with good-natured competition in the context of shared experiences and shared values.

Conserving the forgotten: New insights from a Central African biodiversity hotspot on the anthropogenic perception of nocturnal primates (Mammalia: Strepsirrhini)

The growing dependence of villagers on local forests (food, wood, etc.) makes the comparative assessment of the perceptions they have of the forest and its wildlife increasingly important for setting conservation priorities. While hunting and habitat loss are important threats to primates' existence worldwide, more attention has been focused on diurnal species, while little is known about their nocturnal counterparts. Strepsirrhini is a group of nocturnal primates with galago and potto as the only representatives on mainland Africa. To assess the perception of locals and their impacts on the conservation of these primates, questionnaires were administered to 79 household heads in four villages located in community forests around Mount Cameroon National Park. Amongst the respondents, over 90% admitted that these animals are eaten in their communities. Nocturnal primates were not only hunted for food, but also used in medicine and rituals and to make drums. However, the habit of eating nocturnal primates seems to be uncommon, as most respondents had not consumed any primate bushmeat in the last 5 years. The knowledge and support of wildlife conservation manifested by the villagers did not reflect the reality on the ground, as forest clearing for agriculture takes place regularly across the villages. Our findings suggest that bushmeat is not the main threat to nocturnal primates in this area, with habitat loss potentially representing a bigger problem for their existence in the near future.

March Mammal Madness and the power of narrative in science outreach

March Mammal Madness is a science outreach project that, over the course of several weeks in March, reaches hundreds of thousands of people in the United States every year. We combine four approaches to science outreach - gamification, social media platforms, community event(s), and creative products - to run a simulated tournament in which 64 animals compete to become the tournament champion. While the encounters between the animals are hypothetical, the outcomes rely on empirical evidence from the scientific literature. Players select their favored combatants beforehand, and during the tournament scientists translate the academic literature into gripping "play-by-play" narration on social media. To date ~1100 scholarly works, covering almost 400 taxa, have been transformed into science stories. March Mammal Madness is most typically used by high-school educators teaching life sciences, and we estimate that our materials reached ~1% of high-school students in the United States in 2019. Here we document the intentional design, public engagement, and magnitude of reach of the project. We further explain how human psychological and cognitive adaptations for shared experiences, social learning, narrative, and imagery contribute to the widespread use of March Mammal Madness.

The ripples of modernity: How we can extend paleoanthropology with the extended evolutionary synthesis

Contemporary understandings of paleoanthropological data illustrate that the search for a line defining, or a specific point designating, "modern human" is problematic. Here we lend support to the argument for the need to look for patterns in the paleoanthropological record that indicate how multiple evolutionary processes intersected to form the human niche, a concept critical to assessing the development and processes involved in the emergence of a contemporary human phenotype. We suggest that incorporating key elements of the Extended Evolutionary Synthesis (EES) into our endeavors offers a better and more integrative toolkit for modeling and assessing the evolution of the genus Homo. To illustrate our points, we highlight how aspects of the genetic exchanges, morphology, and material culture of the later Pleistocene complicate the concept of "modern" human behavior and suggest that multiple evolutionary patterns, processes, and pathways intersected to form the human niche.

A meta-analysis of anthropogenic impacts on physiological stress in wild primates

As humanity continues to alter the environment extensively, comprehending the effect of anthropogenic disturbances on the health, survival, and fitness of wildlife is a crucial question for conservation science. Many primate populations occupy suboptimal habitats prone to diverse anthropogenic disturbances that may be sources of acute and chronic stress. Quantification of glucocorticoid (GC) concentrations has repeatedly been used to explore the impact of disturbances on physiological stress. Although it is still debated, prolonged elevation of GC levels may impair reproduction, growth, and immune system activity of individuals. We quantified the effect of anthropogenic disturbances on physiological stress in primates with a global meta-analysis based on data from 26 articles, covering 24 distinct species in 13 different countries. Anthropogenic disturbances were classified into 6 distinct categories: habitat loss, habitat degradation, ongoing logging, hunting, tourism, and other human activities. We calculated effect sizes (Hedges' g) with the standardized mean difference in GC concentrations between primates affected by human activity and their undisturbed conspecifics. We ran random-effects models and subgroup analyses to estimate the overall effect as well as a cumulative effect size for each disturbance category. Overall, primates inhabiting sites subject to anthropogenic disturbances exhibited significantly higher GC levels (g = 0.60; 95% CI: 0.28-0.93). Habitat loss and hunting were overall associated with increased GC concentrations, whereas the cumulative effects of the other disturbances were not statistically significant. Biologically, high GC levels may increase fitness by enabling individuals to overcome the challenges linked to anthropogenic disturbances. However, primates in disturbed environments may have sustained elevated GC levels. To strengthen future research, it is necessary to control confounding factors systematically (e.g., diet, reproductive status, predatory pressure, and resource availability) and improve understanding of the link between GC levels and the health, fitness, and survival of animals.

Community-based conservation and chimpanzee research in Gishwati forest, Rwanda

As great ape populations around the world continue to decline, largely due to anthropogenic activities, conservation programs aimed at supporting these efforts have had mixed success. Here, we evaluate our community-based conservation program in Gishwati forest, Rwanda, aimed at helping to restore biodiversity and ecosystem services using chimpanzees as a flagship species. We examine the effectiveness of this program on reducing one of the ongoing threats to Gishwati's population of chimpanzees, illegal cattle grazing as well as the program's influence on the size of the chimpanzee population. We monitored illegal cattle grazing during several study periods between 2009 and 2019 in Gishwati forest following the implementation of our conservation program in 2008 that included law enforcement, community engagement, and research components. We found that when our conservation program was active, illegal cattle grazing was reduced to low levels. We also observed an increase in the chimpanzee population size during the 11 years since we started our conservation program. We examine how this reduction in cattle grazing and increase in chimpanzee population size may have been influenced by our community-centered approach and discuss the future of our conservation work in Gishwati.

Habitat suitability for primate conservation in north-east Brazil

Brazil has a high diversity of primates, but increasing anthropogenic pressures and climate change could influence forest cover in the country and cause future changes in the distribution of primate populations. Here we aim to assess the long-term suitability of habitats for the conservation of three threatened Brazilian primates (Alouatta belzebul, Sapajus flavius and Sapajus libidinosus) through (1) estimating their current and future distributions using species distribution models, (2) evaluating how much of the areas projected to be suitable is represented within protected areas and priority areas for biodiversity conservation, and (3) assessing the extent of remaining forest cover in areas predicted to be suitable for these species. We found that 88% of the suitable areas are outside protected areas and only 24% are located in areas with forest cover. Although not within protected areas, 27% of the climatically suitable areas are considered priority areas for conservation. Future projections, considering a severe climate change scenario, indicate that A. belzebul, S. flavius and S. libidinosus may lose up to 94, 98 and 54% of their suitable range, respectively. The establishment of primate populations and their long-term survival in these areas are at risk. Mitigation actions such as the implementation of new protected areas, forest restoration and reduction of greenhouse gas emissions will be essential for the conservation of Brazilian primates.

Factors influencing taxonomic unevenness in scientific research: a mixed-methods case study of non-human primate genomic sequence data generation

Scholars have noted major disparities in the extent of scientific research conducted among taxonomic groups. Such trends may cascade if future scientists gravitate towards study species with more data and resources already available. As new technologies emerge, do research studies employing these technologies continue these disparities? Here, using non-human primates as a case study, we identified disparities in massively parallel genomic sequencing data and conducted interviews with scientists who produced these data to learn their motivations when selecting study species. We tested whether variables including publication history and conservation status were significantly correlated with publicly available sequence data in the NCBI Sequence Read Archive (SRA). Of the 179.6 terabases (Tb) of sequence data in SRA for 519 non-human primate species, 135 Tb (approx. 75%) were from only five species: rhesus macaques, olive baboons, green monkeys, chimpanzees and crab-eating macaques. The strongest predictors of the amount of genomic data were the total number of non-medical publications (linear regression; r ² = 0.37; p = 6.15 × 10^-12) and number of medical publications (r ² = 0.27; p = 9.27 × 10^-9). In a generalized linear model, the number of non-medical publications (p = 0.00064) and closer phylogenetic distance to humans (p = 0.024) were the most predictive of the amount of genomic sequence data. We interviewed 33 authors of genomic data-producing publications and analysed their responses using grounded theory. Consistent with our quantitative results, authors mentioned their choice of species was motivated by sample accessibility, prior published work and relevance to human medicine. Our mixed-methods approach helped identify and contextualize some of the driving factors behind species-uneven patterns of scientific research, which can now be considered by funding agencies, scientific societies and research teams aiming to align their broader goals with future data generation efforts.

Network analysis as a tool to understand social development in spider monkeys

The emerging field of network science has demonstrated that an individual's connectedness within their social network has cascading effects to other dimensions of life. Like humans, spider monkeys live in societies with high fission-fusion dynamics, and are remarkably social. Social network analysis (SNA) is a powerful tool for quantifying connections that may vary as a function of initiating or receiving social behaviors, which has been described as shifting social roles. In primatology, the SNA literature is dominated by work in catarrhines, and has yet to be applied to the study of development in a platyrrhine model. Here, SNA was utilized in combination with R-Index social role calculation to characterize social interaction patterns in juvenile and adult Colombian spider monkeys (Ateles fusciceps rufiventris). Connections were examined across five behaviors: embrace, face-embrace, grooming, agonism, and tail-wrapping from 186 hr of observation and four network metrics. Mann-Whitney U tests were utilized to determine differences between adult and juvenile social network patterns for each behavior. Face-embrace emerged as the behavior with different network patterns for adults and juveniles for every network metric. With regard to social role, juveniles were receivers, not initiators, for embrace, face-embrace, and grooming (ps < .05). Network and social role differences are discussed in light of social development and aspects of the different behaviors.

Patterns and magnitudes of craniofacial covariation in extant cercopithecids

The cranium contains almost all of the vertebrate sensory organs and plays an essential role in vertebrate evolution. Research on the primate cranium has revealed that it is both highly integrated and modular, but studies have historically focused on covariance between the neurocranium and facial skeleton rather than on bones specific to special senses such as vision. The goal of this work is to investigate patterns and magnitudes of craniofacial covariation in extant cercopithecids with particular attention to the orbits. This study takes a quantitative approach using data collected from 38 homologous cranial landmarks across 11 genera of cercopithecid monkeys (Cercopithecidae, N = 291). These data demonstrate that both patterns and magnitudes of craniofacial covariation differ across Cercopithecidae at subfamily, tribe, and genus levels, with the strongest integration in the papionins (and specifically Papio) and significantly weaker covariation in the colobines, particularly Presbytis. Orbital height does not covary with other measurements of the cranium to the same degree as other cranial traits in Cercopithecidae and is highly constrained across the family. This study has important implications for our understanding of the evolution and development of morphological diversity in the cercopithecid cranium and evolution of the primate eye. This study also highlights the potential error of broad assumptions about generalizing patterns and magnitudes of modularity and integration across primates. Additionally, these findings reiterate the importance of trait selection for interpreting fossil taxonomy, as craniofacial covariation may impact phenotypes commonly used to differentiate fossil primate species.

Factors influencing infant sex ratio in howler monkeys (Alouatta spp.): A literature review and analysis

OBJECTIVE

Frequency-dependent selection is expected to maintain infant sex ratios around parity over evolutionary time. However, over ecological time periods, infant sex ratios vary, and it has been proposed that this variation may reflect adaptive processes. In primates, there are consistent patterns of variation in infant sex ratios, although their adaptive significance remains contentious. In addition to design issues, contrasting results could have derived across primates from variation in the fitness benefits accrued through sons or daughters associated with the specific social, ecological, and demographic context of populations. Thus, different sex allocation tactics could occur within species over time and space.

METHODS

We reviewed the literature to describe variation in infant sex ratio in howler monkeys (genus Alouatta) and to examine whether such a variation could be associated with adaptive sex allocation. We found 26 studies that provided data for this review. These studies yielded 96 infant sex reports, corresponding to 1,477 sexed infants.

RESULTS

Infant sex ratio across howler monkey species tends to parity, but females produce more sons under high group densities and more daughters when rainfall increases.

DISCUSSION

Based on these results, as well as on information on howler monkey dispersal patterns, demography, and within-group genetic relatedness, we speculate that, depending on population growth stage, sex allocation is explained by (a) local resource enhancement, that is, more cooperative philopatric daughters are produced when populations are growing; and (b) local resource competition, that is, more dispersing sons are produced when populations are saturated. Thus, there is evidence suggestive of adaptive variation in infant sex ratios in howler monkeys.

Are social media reports useful for assessing small ape occurrence? A pilot study from Peninsular Malaysia

Citizen science-based research has been used effectively to estimate animal abundance and breeding patterns, to monitor animal movement, and for biodiversity conservation and education. Here, we evaluate the feasibility of using social media observations to assess the distribution of small apes in Peninsular Malaysia. We searched for reports of small ape observations in Peninsular Malaysia on social media (e.g., blogs, Facebook, Instagram, Twitter, YouTube, iNaturalist, etc.), and also used online, radio, print messaging, and word of mouth to invite citizen scientists such as birders, amateur naturalists, hikers, and other members of the public to provide information about small ape observations made during their activities. These reports provided new information about the occurrence of all three species of small apes (Hylobates agilis, Hylobates lar, and Symphalangus syndactylus) in Peninsular Malaysia. Social media users reported observations of small apes in almost every state. Despite the fact that small apes are believed to occur primarily in the interior of large forested areas, most observations were from fairly small (<100 km² ) forests near areas of high traffic and high human population (roads and urban areas). This suggests that most outdoor enthusiasts primarily visit well-traveled and easily accessible areas, which results in biased sampling if only incidental observations reported on social media are used. A more targeted approach specifically soliciting reports from citizen scientists visiting large, less-accessible forests may result in better sampling in these habitats. Social media reports indicated the presence of small apes in at least six habitats where they had not been previously reported. We verified the reported data based on whether reports included a date, location, and uploaded photographs, videos and/or audio recordings. Well-publicized citizen science programs may also build awareness and enthusiasm about the conservation of vulnerable wildlife species.

The what and where of primate field research may be failing primate conservation

With approximately 30% of nonhuman primate species listed as critically endangered, the window of opportunity to conserve primates is closing fast. In this article, we focus on the degree to which publications in field primatology are biased in favor of particular taxa and field sites. We examined more than 29,000 peer‐reviewed articles and identified 876 field visits to 349 field sites. We found a highly clumped distribution by site and species. We also examined publication ethical statements and the extent to which they acknowledged local human communities (<5%). Due to a lack of consistency across publications, we provide recommendations for improving ethical statements and for evaluating research impact. Given the plight of primate biodiversity, these results suggest broader coverage of primate species and geographies, as well as more attention to the local human communities whose support is necessary if the intent is to have primate species in the wild in the 22nd century.