Paul A. Garber

• Ph.D
• Professor at University of Illinois Urbana-Champaign

Behavioral and dietary flexibility allow primates to effectively exploit resources that fluctuate in time and space. Here we examined monthly variation in the diet and activity budget of a wild nonprovisioned group of Tibetan macaques inhabiting Mt. Huangshan, China. From October 2022 to September 2023, we recorded the behavior of a group of wild m...

Golden snub-nosed monkeys (Rhinopithecus roxellana) live in multilevel societies of over 100 individuals. Despite exploiting low visibility high-altitude forests and home ranges of 14 km², they maintain large and cohesive social networks that serve to coordinate travel and daily activities effectively. During traveling, foraging, and feeding, golde...

The impact of negative selection against deleterious mutations in endangered species remains underexplored. Recent studies have measured mutation load by comparing the accumulation of deleterious mutations, however, this method is most effective when comparing within and between populations of phylogenetically closely related species. Here, we intr...

In the last century, global pandemics have been primarily driven by respiratory infections, which consistently rank among the top 20 causes of death worldwide. The coronavirus disease 2019 (COVID-19) pandemic has underscored the intricate nature of managing multiple health crises simultaneously. In recent years, climate change has emerged as a majo...

Habitat destruction, land conversion, and forest fragmentation over the past several decades have resulted in major declines and local extirpation of wild animal and plant species. The gray snub-nosed monkey (Rhinopithecus brelichi) is currently listed among the 25 most endangered primate species in the world, with an estimated remaining wild popul...

The gut microbiome has the potential to buffer temporal variations in resource availability and consumption, which may play a key role in the ability of animals to adapt to a broad range of habitats. We investigated the temporal composition and function of the gut microbiomes of wild common marmosets (Callithrix jacchus) exploiting a hot, dry envir...

The gut microbiota plays a crucial role in regulating energy metabolism, facilitating nutrient absorption, and supporting immune function, thereby assisting the host in adapting to seasonal dietary changes. Here, we compare the gut microbiome composition of wild gray snub-nosed monkeys during winter (from October to December) and spring (from Janua...

A growing global human population, habitat conversion, and the indiscriminate exploitation of natural resources have created unsustainable demands on nature, resulting in widespread biodiversity loss. Primates, which represent the third most specious Order of mammals, are facing an extinction crisis. Currently, 69% of primate species are listed by...

The global trade in nonhuman primates represents a substantial threat to ecosystem health, human health, and primate conservation worldwide. Most of the primate trade involves trade for pet-keeping, consumption, or biomedical experimentation. We present an overview of international primate trade through five case studies; each describes a different...

Aim If species fail to track the pace of climate change, areas of suitable habitat and population size are likely to decline, threatening species survivorship. Here, we incorporated multiple measures of environmental change and species‐specific habitat requirements to assess the responses of two closely related primate species to future changes in...

Climate oscillations may drive the divergence of ancestral species through habitat isolation, species distribution patterns, and the cessation of gene flow. However, traditional ecological niche models lack the consideration for the genetic adaptation of species, thus it’s difficult to understand how climate oscillations affect species divergence b...

Nonhuman primates and their habitats are facing an impending extinction crisis. Approximately 69% of primate species are listed by the International Union for Conservation of Nature as threatened and 93% have declining populations. Human population growth (expected to reach 10.9 billion by the year 2100), the unsustainable demands of a small number...

Song coordination is a universal characteristic of human music. Many animals also produce well-coordinated duets or choruses that resemble human music. However, the mechanism and evolution of song coordination have only recently been studied in animals. Here, we studied the mechanism of song coordination in three closely related species of wild Nom...

Human activity and climate change affect biodiversity and cause species range shifts, contractions, and expansions. Globally, human activities and climate change have emerged as persistent threats to biodiversity, leading to approximately 68% of the ~522 primate species being threatened with extinction. Here, we used habitat suit-ability models and...

Provisioning can significantly affect the ranging patterns, foraging strategies, and time budget of wild primates. In this study, we document for the first time, the effects of provisioning on the activity budget and foraging effort in an Asian colobine. Over 3-years, we used an instantaneous scanning method at 10-min intervals to collect data on t...

Given that 64% of nonhuman primate species are threatened with extinction, science-based conservation action is urgently needed to protect their imperiled populations. However, lack of key information on species due to a research bias can hinder effective conservation actions. We examined taxonomic bias in global primate research and employed phylo...

The biological mechanisms that underpin primate social evolution remain poorly understood. Asian colobines display a range of social organizations, which makes them good models for investigating social evolution. By integrating ecological, geological, fossil, behavioral, and genomic analyses, we found that colobine primates that inhabit colder envi...

Primates are facing an impending extinction crisis. Here, we examine the set of conservation challenges faced by the 100 primate species that inhabit the Brazilian Amazon, the largest remaining area of primary tropical rainforest in the world. The vast majority (86%) of Brazil's Amazonian primate species have declining populations. Primate populati...

Food availability and climate represent environmental factors that affect species' social behavior, ranging patterns, diet, and activity budget. From August 2012 to September 2013, we examined the effects of seasonal changes in food availability, temperature, and rainfall on the diet and behavioral ecology of Shortridge's langur (Trachypithecus sho...

Aim Determining the mechanisms by which climate change and human activities affect patterns of ecological specialization in different genetic units of the same species is crucial for developing local or regionally‐based conservation solutions. This study uses species distribution models and genetic analysis to (1) identify the evidence of intraspec...

Hainan gibbons are among the world's most critically endangered primates, with a remaining population of only 35 individuals distributed across five social groups in the Bawangling Branch of the Hainan Tropical Rainforest National Park, China. Habitat conversion and forest fragmentation over the past 40 years have reduced their geographical distrib...

Primates, represented by 521 species, are distributed across 91 countries primarily in the Neotropic, Afrotropic, and Indo-Malayan realms. Primates inhabit a wide range of habitats and play critical roles in sustaining healthy ecosystems that benefit human and nonhuman communities. Approximately 68% of primate species are threatened with extinction...

Reducing conflict between humans and wildlife is considered a top conservation priority. However, increasingly human-induced disturbances across natural landscapes have escalated encounters between humans and wildlife. In Nepal, forests have been destroyed, fragmented, and developed for human settlements, agricultural production, and urban centers...

Mammals rely on the metabolic functions of their gut microbiota to meet their energetic needs and digest potentially toxic components in their diet. The gut microbiome plastically responds to shifts in host diet and may buffer variation in energy and nutrient availability. However, it is unclear how seasonal differences in the gut microbiome influe...

Climate oscillations may drive the divergence of ancestral species through climatic suitability isolation, effective population contraction, and the cessation of gene flow. However, traditional ecological niche models fail to consider gene flow and the historical demography of a species, and thus provide limited insight into how climate oscillation...

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 analys...

Traditionally, the genus Rhinopithecus (Milne‐Edwards, 1872, Primates, Colobinae) included four allopatric species, restricted in their distributions to China and Vietnam. In 2010, a fifth species, the black snub‐nosed monkey (Rhinopithecus strykeri) was discovered in the Gaoligong Mountains located on the border between China and Myanmar. Despite...

Understanding flexibility in the social structure and mating strategies of the world’s last remaining population (35 individuals) of wild Hainan gibbons (Nomascus hainanus) is critical for developing effective management plans to aid in their population recovery. Three of the five remaining Hainan gibbon groups (A, B, and C) currently live in a soc...

Primates are facing a global extinction crisis driven by an expanding human population, environmental degradation, the conversion of tropical forests into monocultures for industrial agriculture and cattle ranching, unsustainable resource extraction, hunting, climate change, and the threat of emerging zoonotic diseases. And, although many primate s...

Nonhuman primates are facing an impending extinction crisis with over 65% of species listed as Vulnerable, Endangered, or Critically Endangered, and 93% characterized by declining populations. Primary drivers of primate population decline include deforestation, principally for industrial agriculture and the production of food and nonfood commoditie...

In mammal herbivores, fiber digestion usually occurs predominantly in either the foregut or the hindgut. Reports of mechanisms showing synergistic function in both gut regions for the digestion of fiber and other nutrients in wild mammals are rare since it requires integrative study of anatomy, physiology and gut microbiome. Colobine monkeys (Colob...

Within‐group competition over food resources can be a major cost of social living. In the wild, foragers are confronted with social (e.g. hierarchical rank) and ecological (e.g. food availability and distribution) challenges that affect their foraging decisions and feeding success. Exhibiting prosocial behaviours, such as tolerance at feeding sites...

The distribution and availability of microbes in the environment has an important effect on the composition of the gut microbiome of wild vertebrates. However, our current knowledge of gut-environmental interactions is based principally on data from the host bacterial microbiome, rather than on links that establish how and where hosts acquire their...

Protecting biodiversity and reducing human poverty is a global challenge to all countries, including China, which has high biodiversity, large urban centers, and a large human population. Here, we discussed the effects of policies designed to alleviate poverty (Ecological Emigration, Ecological Restoration and Ecotourism) on the conservation status...

In many areas of South Asia and Southeast Asia, macaques inhabiting agricultural landscapes are considered serious crop pests by local farmers. In Nepal, for example, the expansion of monocultures, increased forest fragmentation, the degradation of natural habitats, and changing agricultural practices have led to a significant increase in the frequ...

Changes in land use and the conversion of natural forests to agricultural fields and cattle pastures are threatening the survival of many species of wild animals, including nonhuman primates. Given its almost 1.4 billion people, China faces a difficult challenge in balancing economic development, human well-being, environmental protection, and anim...

In group-living mammals, an individual's fitness depends, in part, on the quality of social relationships it has with others. Among species of nonhuman primates in which one sex is philopatric, individuals of that sex often develop strong social bonds and alliances with closely related kin. Less is known regarding the social processes used by dispe...

Background: In mammal herbivores, the digestion of fiber usually occurs predominantly in either the foregut or in the hindgut. However, how both gut regions function synergistically in the digestion of fiber and other nutrients has rarely been reported in wild mammals. This requires an integrative study of host anatomy, physiology and gut microbiom...

To increase efficiency in the search for resources, many animals rely on their spatial abilities. Specifically, primates have been reported to use mostly topological and rarely Euclidean maps when navigating in large-scale space. Here, we aimed to investigate if the navigation of wild common marmosets inhabiting a semiarid environment is consistent...

Although recent studies have revealed that gut fungi may play an important functional role in animal biology and health, little is known concerning the effects of anthropogenic pressures on the gut mycobiome. Here, we examined differences of the gut mycobiome in wild and captive populations of Tibetan macaques ( Macaca thibetana ) targeting the fun...

The Hainan gibbon (Nomascus hainanus) is endemic to China and is the world’s rarest ape. The remaining wild population totals only 33 individuals. In the current study, we sequenced the Mitochondrial DNA control region of 12 wild Hainan gibbons representing three social groups of the five remaining groups. By conducting population genetic analyses,...

Theories proposed to explain social play have centered on its function in establishing social relationships critical for adulthood, its function in developing motor skills needed to survive, and promoting cognitive development and social learning. In this study, we compared variations in social play among infant and juvenile male and female Macaca...

Hierarchical steepness, defined as status asymmetries among conspecifics living in the same group, is not only used as a main characteristic of animal social relationships, but also represents the degree of discrepancy between supply and demand within the framework of biological market theory. During September and December 2011, we studied hierarch...

The Hainan gibbon (Nomascus hainanus), once widespread across Hainan, China, is now found only in the Bawangling National Nature Reserve. With a remaining population size of 33 individuals, it is the world’s rarest primate. Habitat loss and fragmentation are the primary drivers of Hainan gibbon population decline. In this study, we integrated data...

Coronavirus disease 2019 (COVID-19) and other epidemics (such as severe acute respiratory syndrome [SARS], Ebola, and H1N1) are stark reminders that knowledge of animal behavior and ecosystem health are key to controlling the spread of zoonotic diseases early in their onset. However, we have very limited information about the set of behavioral and...

Lateralized behavior is considered an observable phenotype of cerebral functional asymmetry and has been documented in many mammalian species. In the present study, we examined evidence of lateralization in neonatal nipple contact, maternal cradling, and the relationship between these two behaviors during the first 12 weeks of life in wild Taihangs...

Birth attendance, or midwifery service, is an important characteristic in human evolution, and has been argued to separate our lineage from other taxa in the animal kingdom. Recent studies, however, indicate that similar or analogous behaviors also may occur in a small number of nonhuman primate species. Here, we report the first case of both male...

Studies of feeding patch choice in primates have traditionally analyzed individual foraging decisions in relation to patterns of social foraging, dominance, and feeding competition. However, information on detailed ecological and nutritional characteristics of the patches also is needed to understand the basis of feeding patch preferences. In parti...

Currently, ~65% of extant primate species ( ca 512 species) distributed in 91 countries in the Neotropics, mainland Africa, Madagascar, South Asia and Southeast Asia are threatened with extinction and 75% have declining populations as a result of deforestation and habitat loss resulting from increasing global market demands, and land conversion for...

Population size is a critical indicator used to assess the demographic profile and conservation status of animal species living in disturbed habitats. Using GIS technology, we calculated the remaining habitat area and estimated the population size of the Guizhou snub-nosed monkey (Rhinopithecus brelichi), an Endangered primate endemic to China. The...

Hair cortisol concentration (HCC) provides a long-term retrospective measure of hypothalamic-pituitary-adrenal axis activity, and is increasingly used to assess the life history, health and ecology of wild mammals. Given that sex, age, season and pregnancy influence HCC, and that it may indicate ongoing stress, we examined HCC in common marmosets (...

Leadership is a key issue in the study of collective behavior in social animals. Affiliation-leadership models predict that dyadic partner preferences based on grooming relationships or alliance formation positively affect an individual’s decision to follow or support a conspecific. In the case of many primate species, females without young infants...

In mammals characterized by a mating system in which a single male monopolizes reproduction, infanticide is reported to occur following a male take-over, often resulting in females returning to oestrus more rapidly than if their infant has survived. However, over the course of a 17-year study of golden snub-nosed monkeys, Rhinopithecus roxellana, a...

In the face of ongoing habitat fragmentation, many primate species have experienced reduced gene flow resulting in a reduction of genetic diversity, population bottlenecks and inbreeding depression, including golden snub-nosed monkeys Rhinopithecus roxellana. Golden snub-nosed monkeys live in a multilevel society composed of several one male harem...

The study of vocal communication in nonhuman primates, especially apes, offers critical insight into the origins of human language. Although human language represents a highly derived and complex form of communication, researchers have found that the organization of language follows a series of common statistical patterns, known as ‘linguistic laws...

Anthropogenic changes and fragmentation of natural habitats often exert a negative effect on resource availability and distribution, and the nutritional ecology and feeding behavior of nonhuman primates. The goals of this study are to examine food choice and to identify the nutritional profile of foods consumed by the Critically Endangered black sn...

Given their shared evolutionary history with humans, nonhuman primates play an exceptional role in the study of animal behavior, ecology, and evolution. This close phylogenetic relationship has led scholars from a diverse set of disciplines (e.g., biological and social sciences, notably psychology and anthropology) and theoretical perspectives (e.g...

In this chapter, our goal is to review the evidence for multiple behavioral exchange and interchange in Tibetan macaque groups at Mt. Huangshan, China, and to analyze these dyadic behavioral interactions within the context of behavioral exchange or interchange. We focus on grooming exchanges (grooming vs. grooming), the interchange of grooming for...

Commodity production, extraction, and consumption are taking a heavy toll on key primate habitats around the world.

Gibbons represent a highly successful radiation of four genera and 20 species of Asian apes that, in response to recent habitat fragmentation and deforestation, are threatened with extinction. China has six species of gibbons, each of which is critically endangered. We present new biogeographical information on the distribution of the black crested...

To understand animal behavior, we need to know more about how the brain works. Magnetic resonance imaging (MRI) is a noninvasive imaging technology that has been widely used to examine the functional basis of human decision-making and the interplay between neuroanatomy, endocrinology, and behavior. In this chapter, we argue that recent advances in...

Field studies of wild nonhuman primates have grown exponentially over the past 40 years and our knowledge of primate behavior, ecology, and social, and mating systems has expanded greatly. However, we are facing a major extinction crisis with some 60% of all primate species listed as threatened and more than 75% of species with declining population...

The gut microbiome of primates, including humans, is reported to closely follow host evolutionary history, with gut microbiome composition being specific to the genetic background of its primate host. However, the comparative models used to date have mainly included a limited set of closely related primates. To further understand the forces that sh...

Difficult to study species that inhabit inaccessible terrain, present significant challenges in obtaining accurate ecological, distributional, and conservation information. To address these challenges, we used an effective set of time- and cost-efficient methods including interview-based surveys assisted by Google earth 3D maps to document the dist...

Table S9 - Percent of total number of primate species threatened with extinction due to 10 human land use types under current and six future scenarios for 2050 and 2100

Table S8 - Percent of primate species threatened with extinction currently (2016) and under six future scenarios for 2050 and 2100

As a consequence of recent human activities. populations of approximately 75% of the world's primates are in decline, and more than 60% of species (n = 512) are threatened with extinction. Major anthropogenic pressures on primate persistence include the widespread loss and degradation of natural habitats caused by the expansion of industrial agricu...

Body mass is a strong predictor of diet and nutritional requirements across a wide range of mammalian taxa. In the case of small‐bodied primates, because of their limited gut volume, rapid food passage rate, and high metabolic rate, they are hypothesized to maintain high digestive efficiency by exploiting foods rich in protein, fats, and readily av...

Understanding the set of factors that promote and constrain a species' ability to exploit ecologically distinct habitats is central for addressing questions of intraspecific variability in behavior and morphology. In this study, we compared newly collected data with published data on body measurements, group size and composition, daily path length,...

Background: Endogenous retroviruses (ERV) are remnants of former exogenous retroviruses that had previously invaded the germ line of the host that can be vertically transmitted across generations. While the majority of ERVs lack infectious capacity due to the accumulation of deleterious mutations, some ERVs remain active and produce potentially in...

In this study, we integrate data from field investigations, spatial analysis, genetic analysis, and Generalized Linear Models (GLMs) to evaluate the effects of habitat fragmentation on the population dynamics, genetic diversity, and range shifts in the endangered Yunnan snub-nosed monkey ( Rhinopithecus bieti ). The results indicate that from 1994...

Since its initial discovery in 2010 in the Gaoligong Mountains on the Sino–Myanmar border, there remains no direct information on the feeding habits of the black snub-nosed monkey (Rhinopithecus strykeri). This species is on the verge of extinction, with an estimated remaining population of < 400 individuals. Due to difficulties in following these...

Correlational models are widely used to predict changes in species' distribution, but generally have failed to address the comprehensive effects of anthropogenic activities, climate change, habitat connectivity and gene flow on wildlife sustainability. Here, we used integrated approaches (MAXENT model, circuit model and genetic analysis) to assess...

While regular allomaternal nursing (suckling) has been documented in a number of rodent and carnivore species, as well as in some prosimians, New World monkeys, and humans, it is not common in Old World monkeys and apes. Here, we present a detailed field study of allomaternal nursing in golden snub-nosed monkeys ( Rhinopithecus roxellana , Colobina...

Models of primate sociality focus on the costs and benefits of group living and how factors such as rank, feeding competition, alliance formation, and cooperative behavior shape within‐group social relationships. We conducted a series of controlled field experiments designed to investigate how resource distribution (one or three of four reward plat...

China is facing an unprecedented set of challenges in balancing the effects of economic development and global climate change with environmental protection and maintaining biodiversity. Although positive steps have been undertaken to remedy this situation, currently 80% of China’s 25 extant primate species are threatened, 15–18 species have populat...

Between September 2011 and August 2013, we studied patterns of habitat selection and habitat use in the Guizhou golden monkey (Rhinopithecus brelichi) at Fanjingshan National Nature Reserve, China. the monkeys ranged across elevations between 1432 and 2100 m. Within this altitudinal range we recorded 125 genera, 72 families, and 236 tree and vine s...

Male–male interactions in mixed‐sex groups of social mammals are typically characterized by a mix of hostility and affiliation, as a result of inherent conflicts over mating opportunities, and the costs and benefits of social alliances, co‐operative behaviors, and coalitionary defense. In species of nonhuman primates that form all‐male groups, it i...

DNA metabarcoding is a powerful tool for assessing the diets of wild animals, but there is no clear consensus on which proposed plant barcoding marker is most suitable for dietary analysis. This study compares two DNA plant barcoding markers that are commonly used for dietary analyses from degraded DNA, rbcL and trnL, to detailed dietary observatio...