W S Mcgraw
Biographic Data
| ID | 12543 |
|---|---|
| NAME | W S Mcgraw |
| GIVEN NAMES | W S |
| FAMILY NAME | Mcgraw |
| SIGNATURE | MCGRAW W S |
| AFFILIATIONS | The Ohio State University |
| ORCID | 0000-0003-1986-7408 |
| VERIFIED | Yes |
| TOTAL WORKS | 55 |
| TOTAL CITATIONS | 401 |
| AUTHOR COUNT | 55 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1996 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 12 |
Evolutionary history of the endangered Sanje mangabey (Cercocebus sanjei) in the Udzungwa Mountains, Tanzania
Understanding whether a species’ distribution results from recent and/or anthropogenic events or ancient vicariant factors is critical for conservation planning. The Endangered Sanje mangabey ( Cercocebus sanjei ), endemic to Tanzania’s Udzungwa Mountains, is currently divided into two populations located approximately 100 km apart. These represent distinct evolutionary lineages that diverged around 0.77 million years ago (MYA). We aimed to inves…
Dietary Adaptation in Paranthropus robustus Postcanine Teeth
Baboons and the Paleobiology of Paranthropus
The Meaning of Mangabey Molars (And Premolars)
The postcanine teeth of mangabeys (members of Cercocebus and Lophocebus ) have figured prominently in discussions about the relationship between hard‐object feeding and dental form. Grey‐cheeked mangabeys ( Lophocebus albigena ) and sooty mangabeys ( Cercocebus atys ) both have thickly enameled posterior teeth. Thick enamel in the former is argued to be response to fallback consumption of hard‐object foods, whereas in the latter, this feature is …
On the Phylogenetic History of the Sanje Mangabey (Cercocebus sanjei), Udzungwa Mountains, Tanzania
An accurate understanding of phylogeny, including intraspecific diversity, is key for defining conservation measures. The Sanje mangabey ( Cercocebus sanjei ) is an Endangered primate endemic to the Udzungwa Mountains in Tanzania that inhabits montane forest fragments and occurs in two populations—Mwanihana Forest and Uzungwa Scarp Nature Reserve—located 100 km apart. The phylogenetic position of the Sanje mangabey relative to other Cercocebus sp…
Investigating relationships among strontium, barium, and seasonality in wild baboons
Geochemical profiles of Australopithecus africanus and baboon teeth show fluctuating trace elements, possibly reflecting seasonal diets. Here we use laser ablation–inductively coupled plasma–mass spectrometric measurements of calcium‐normalized strontium and barium ratios (Sr/Ca and Ba/Ca) and ion microprobe analyses of oxygen isotopes (δ 18 O) to contrast elemental changes with seasonal rainfall in wild baboons. We employ 16 teeth from 11 South …
Differences in maxillary premolar form between Cercocebus and Lophocebus
Demography and epidemiology of captive former biomedical research chimpanzees ( Pan troglodytes ) 1
Accurate and up‐to‐date data on longevity and mortality are essential for describing, analyzing, and managing animal populations in captivity. We assembled a comprehensive demography data set and analyzed survival and mortality patterns in a population of captive former biomedical research chimpanzees. The study synthesized over 51,000 life‐years of demographic data collected on 2349 individuals between 1923 and 2014. Our goal was to assess the p…
A histological study of enamel developmental defects in a chacma baboon (Papio ursinus) incisor
Physiological stress disrupts normal growth creating visible grooves on the enamel surface (i.e., linear enamel hypoplasia or LEH). Hypoplastic defects often, but not always, co-occur with internal accentuated lines (AL). Monkeys reportedly exhibit fewer enamel defects than hominoids as their presumably faster-growing teeth produce shallower LEH defects that are harder to macroscopically identify. In this case study of a chacma baboon (Papio ursi…
Aspects of molar form and dietary proclivities of African colobines
Enamel chipping and its ecological correlates in African papionins
Masticatory and ingestive effort in Procolobus verus, a small-bodied African colobine
Dental macrowear, diet, and anterior tooth use in Colobus polykomos and Piliocolobus badius
Seed choice differs by sex in sooty mangabeys (Cercocebus atys)
Locomotion of an adult female and juvenile male aye‐aye ( Daubentonia madagascariensis ) in Torotorofotsy, Madagascar
Aye‐ayes ( Daubentonia madagascariensis ) locate and acquire invertebrates from within woody substrates at all levels of the rainforest; yet how their locomotion helps them accommodate this diet has not been explored in detail. We studied the locomotor behavior of an adult female ( N = 1,085) and juvenile male ( N = 708) aye‐aye in the undisturbed forest of Torotorofotsy, Madagascar from May to December 2017. We used bout sampling to record locom…
Oral processing, sexual selection, and size variation in the circumorbital region of Colobus and Piliocolobus
OBJECTIVES: The function of the browridge in primates is a subject of enduring debate. Early studies argued for a role in resisting masticatory stresses, but recent studies have suggested sexual signaling as a biological role. We tested associations between circumorbital form, diet, oral processing, and social behavior in two species of colobus monkey-the king colobus (Colobus polykomos) and western red or bay colobus (Piliocolobus badius). MATER…
Diet, feeding behavior, and jaw architecture of Taï monkeys
We review feeding and mandibular anatomy in a community of West African monkeys. We use field observations, food material property data, and skeletal specimens from the Ivory Coast's Taï Forest to explore the factors that shape mandibular architecture in colobines and cercopithecines. Despite excellent geographic control across our sample, the fit between bone form (as conventionally described) and functional activity (as we perceive it) is not s…
Enamel chipping in Taï Forest cercopithecids
Long bone structural proportions and locomotor behavior in Cercopithecidae
Forest Floor Leaf Cover as a Barrier for Dust Accumulation in Tai National Park
Effects of Chimpanzee (Pan troglodytes) Hunting Seasonality and Red Colobus (Piliocolobus badius) Association on Diana Monkeys (Cercopithecus diana) in Taï National Park, Côte d’Ivoire
Humeral correlates of forelimb elevation in four West African cercopithecid monkeys
OBJECTIVES: We previously found that differing degrees of forelimb flexion, elevation, and abduction during nonlocomotor foraging activities covaried with scapular morphology among four sympatric cercopithecids. The purpose of this study is to investigate whether features of the proximal humerus are similarly related to forelimb elevation during foraging. METHODS: Our sample consists of humeri (n = 42) of adult Cercocebus atys, Cercopithecus dian…
Spatial variation in mandibular bone elastic modulus and its effect on structural bending stiffness
Objectives We investigated how heterogeneity in material stiffness affects structural stiffness in the cercopithecid mandibular cortical bone. We assessed (1) whether this effect changes the interpretation of interspecific structural stiffness variation across four primate species, (2) whether the heterogeneity is random, and (3) whether heterogeneity mitigates bending stress in the jaw associated with food processing. Materials and methods The s…
Bone remodeling is reduced in high stress regions of the cercopithecoid mandible
OBJECTIVES: Independent lines of evidence suggest that osteonal bone remodeling is a function of both mechanical (i.e., changes in stress) and non-mechanical (i.e., metabolic needs related to calcium liberation) factors. The degree to which secondary bone reflects mechanical factors, however, is incompletely understood despite the common assumption that the stress environment mediates remodeling activity. Here, we investigate whether there are re…
Feeding and oral processing behaviors of two colobine monkeys in Tai Forest, Ivory Coast
Skeletal and dental morphology of African papionins
Feeding, Diet, and Jaw Form in West African Colobus and Procolobus
Sex and age differences in the diet and ingestive behaviors of sooty mangabeys ( Cercocebus atys ) in the Tai forest, Ivory coast
Members of the Cercocebus ‐ Mandrillus clade are united by several morphological features, including expanded premolars which are argued to be associated with a preponderance of hard objects in the diet. We test the association between premolar expansion and hard object feeding by examining how different dental regions are used during food processing. We examined the diet and oral processing activities of sooty mangabeys ( Cercocebus atys ) in th…
Homoplasy and thick enamel in primates
Functional morphology of the mangabey mandibular corpus
Recent molecular and morphological surveys suggest that mangabeys do not represent a monophyletic group. Specifically, Cercocebus is the sister taxon of Mandrillus , whereas Lophocebus forms an unresolved trichotomy with Papio and Theropithecus . The Cercocebus ‐ Mandrillus clade is characterized by skeletal and dental adaptations related to acquisition and processing of hard‐object foods that resist decomposition for months on the forest floor. …
Brief communication
The documentation of enamel thickness variation across primates is important because enamel thickness has both taxonomic and functional relevance. The Old World monkeys commonly referred to as mangabeys have figured prominently in investigations of feeding ecology and enamel thickness. In this article, we report enamel thickness values for four mangabey taxa ( Cercocebus atys , Cercocebus torquatus , Lophocebus aterrimus , and Lophocebus albigena…
Dietary variation and food hardness in sooty mangabeys ( Cercocebus atys )
We present information on food hardness and monthly dietary changes in female sooty mangabeys ( Cercocebus atys ) in Tai Forest, Ivory Coast to reassess the hypothesis that thick molar enamel is parsimoniously interpreted as a response to consumption of hard foods during fallback periods. We demonstrate that the diet of sooty mangabeys varies seasonally, but that one food— Sacoglottis gabonensis —is the most frequently consumed food every month a…
Feeding and oral processing behaviors of two colobine monkeys in Tai Forest, Ivory Coast
Primate remains from African crowned eagle (Stephanoaetus coronatus) nests in Ivory Coast's Tai Forest
Understanding the initial processes of deposition can help with interpretations of fossil assemblages. Here we discuss the taphonomy of primate remains collected under 16 nests of African crowned eagles (Stephanoaetus coronatus) in the Tai Forest, Ivory Coast. From 1,200 bones collected, including 669 primate bones, we calculated minimum number of individuals (MNI), survivability profiles, and damage profiles using methods identical to those empl…
Association of Terrestrial Mangabeys (Cercocebus atys) with Arboreal Monkeys
Primate Feeding and Foraging
Given that something as fundamental as food acquisition is subject to selection pressure, it follows that morphological and behavioral diversity among primates is reflective of a range of adaptations to diet, feeding, and foraging. The recognition of these adaptations, however, is operationally difficult because it is the interaction between morphological and ecological variables that serves to define the particular adaptation. Researchers have a…
Positional Behavior of Cercopithecus petaurista
Dental wear among cercopithecid monkeys of the Taï forest, Côte d'Ivoire
Studies of dental macrowear can be useful for understanding masticatory and ingestive behavior, life history, and for inferring dietary information from the skeletal material of extinct and extant primates. Such studies to date have tended to focus on one or two teeth, potentially missing information that can be garnered through examination of wear patterns across the tooth row. Our study measured macrowear in the postcanine teeth of three sympat…
Brief communication
Recent studies suggest a large raptor such as the crowned eagle ( Stephanaoetus coronatus ) was responsible for collecting at least a portion of the primate fauna from the South African fossil site of Taung, including its lone hominin specimen. This taphonomic signature at Taung is currently regarded as a unique and, most likely, isolated case in primate and human evolution. However, the activities of large, carnivorous birds should also be detec…
Enamel chipping in Taï Forest cercopithecids
Masticatory stress and the mechanics of “wishboning” in colobine jaws
Cercopithecoid monkeys experience relatively high strains along the lingual aspect of the mandibular symphysis because of lateral transverse bending of the mandibular corpora (“wishboning”) during mastication. Hylander (Am J Phys Anthropol 64 (1984) 1–46; Am Zool 25 (1985) 315–330) demonstrated that the distribution of strains arising from wishboning loads is comprehensible with reference to the mechanics of curved beams. Theory of curved beams s…
Locomotion and habitat use of Stampflii's putty‐nosed monkey ( Cercopithecus nictitans stampflii ) in the Taï National Park, Ivory Coast
Stampflii's putty‐nosed monkeys Cercopithecus nictitans stampflii are large, rare, poorly known guenons with a discontinuous distribution in West Africa. Putty‐nosed monkeys occur at low densities in Ivory Coast's Tai National Park where they are believed to have migrated from less forested regions north of the park (Eckardt and Zuberbühler: Behav Ecol 15 (2004) 400–411). In this article, we compare the positional behavior of Putty‐nosed monkeys …
Adult Female Cercopithecus diana Employ Canine Teeth to Kill Another Adult Female C. diana
Reduced stiffness of alveolar bone in the colobine mandible
Alveolar bone has several mechanical functions, including tooth support and accommodation of occlusal and other masticatory forces. Its unique functional‐mechanical environment is reflected by its structural characteristics, but whether alveolar bone is materially distinct from bone elsewhere in the primate facial skeleton is uncertain. This uncertainty is attributable not only to a limited amount of data but also to conflicting findings among th…
Update on the Search for Miss Waldron’s Red Colobus Monkey
Humeral correlates of forelimb elevation in four West African cercopithecid monkeys
OBJECTIVES: We previously found that differing degrees of forelimb flexion, elevation, and abduction during nonlocomotor foraging activities covaried with scapular morphology among four sympatric cercopithecids. The purpose of this study is to investigate whether features of the proximal humerus are similarly related to forelimb elevation during foraging. METHODS: Our sample consists of humeri (n = 42) of adult Cercocebus atys, Cercopithecus dian…
Forest Floor Leaf Cover as a Barrier for Dust Accumulation in Tai National Park
Bone remodeling is reduced in high stress regions of the cercopithecoid mandible
OBJECTIVES: Independent lines of evidence suggest that osteonal bone remodeling is a function of both mechanical (i.e., changes in stress) and non-mechanical (i.e., metabolic needs related to calcium liberation) factors. The degree to which secondary bone reflects mechanical factors, however, is incompletely understood despite the common assumption that the stress environment mediates remodeling activity. Here, we investigate whether there are re…
Ontogeny of material stiffness heterogeneity in the macaque mandibular corpus
Evidence is accumulating that bone material stiffness increases during ontogeny, and the role of elastic modulus in conditioning attributes of strength and toughness is therefore a focus of ongoing investigation. Developmental changes in structural properties of the primate mandible have been documented, but comparatively little is known about changes in material heterogeneity and their impact on biomechanical behavior. We examine a cross‐section…
Long bone structural proportions and locomotor behavior in Cercopithecidae
Cercopithecid locomotion, support use, and support availability in the Tai Forest, Ivory Coast
Habitat heterogeneity is widely theorized to be important in the evolution of Old World monkeys, yet the impact of architecturally distinct forest types on the positional repertoires of African monkeys is largely unknown. As part of a wider project, this study investigates how the locomotor behavior of five sympatric cercopithecids varies in structurally distinct forest areas. Fieldwork took place in the Tai Forest, Ivory Coast, from June 1993 to…
Primate Diversity
Comparative locomotion and habitat use of six monkeys in the Tai Forest, Ivory Coast
The relationships between locomotion, body size, and habitat use in six sympatric Old World monkeys are examined to test whether the associations found are consistent with those demonstrated in previous studies (Fleagle and Mittermeier [1980] Am. J. Phys. Anthropol. 52:301-314; Gebo and Chapman [1995] Am. J. Phys. Anthropol. 97:49-76). Colobus polykomos, C. badius, C. verus, Cercopithecus diana, C. campbelli, and Cercocebus atys were studied for …
Skeletal and dental morphology supports diphyletic origin of baboons and mandrills
Numerous biomolecular studies from the past 20 years have indicated that the large African monkeys Papio , Theropithecus , and Mandrillus have a diphyletic relationship with different species groups of mangabeys. According to the results of these studies, mandrills and drills ( Mandrillus ) are most closely related to the torquatus – galeritus group of mangabeys placed in the genus Cercocebus , whereas baboons ( Papio ) and geladas ( Theropithecu…
Positional Behavior of Cercopithecus petaurista
Feeding, Diet, and Jaw Form in West African Colobus and Procolobus
Adult Female Cercopithecus diana Employ Canine Teeth to Kill Another Adult Female C. diana
Association of Terrestrial Mangabeys (Cercocebus atys) with Arboreal Monkeys
Skeletal and dental morphology of African papionins
Update on the Search for Miss Waldron’s Red Colobus Monkey
Primate remains from African crowned eagle (Stephanoaetus coronatus) nests in Ivory Coast's Tai Forest
Understanding the initial processes of deposition can help with interpretations of fossil assemblages. Here we discuss the taphonomy of primate remains collected under 16 nests of African crowned eagles (Stephanoaetus coronatus) in the Tai Forest, Ivory Coast. From 1,200 bones collected, including 669 primate bones, we calculated minimum number of individuals (MNI), survivability profiles, and damage profiles using methods identical to those empl…
Locomotion and habitat use of Stampflii's putty‐nosed monkey ( Cercopithecus nictitans stampflii ) in the Taï National Park, Ivory Coast
Stampflii's putty‐nosed monkeys Cercopithecus nictitans stampflii are large, rare, poorly known guenons with a discontinuous distribution in West Africa. Putty‐nosed monkeys occur at low densities in Ivory Coast's Tai National Park where they are believed to have migrated from less forested regions north of the park (Eckardt and Zuberbühler: Behav Ecol 15 (2004) 400–411). In this article, we compare the positional behavior of Putty‐nosed monkeys …
Functional morphology of the mangabey mandibular corpus
Recent molecular and morphological surveys suggest that mangabeys do not represent a monophyletic group. Specifically, Cercocebus is the sister taxon of Mandrillus , whereas Lophocebus forms an unresolved trichotomy with Papio and Theropithecus . The Cercocebus ‐ Mandrillus clade is characterized by skeletal and dental adaptations related to acquisition and processing of hard‐object foods that resist decomposition for months on the forest floor. …
Socioecology, predation, and cognition in a community of West African monkeys
The Ivory Coast's Taï Forest is home to a diverse primate fauna, including eight monkey species that interact daily with the environment, each other, and a web of predators. These interactions have led to an array of adaptations, some of which conform to theoretical expectations, and others are at odds with current behavioral ecology models. In this paper, we draw on fifteen years of observations to examine two central issues. First, how do broad…
Masticatory stress and the mechanics of “wishboning” in colobine jaws
Cercopithecoid monkeys experience relatively high strains along the lingual aspect of the mandibular symphysis because of lateral transverse bending of the mandibular corpora (“wishboning”) during mastication. Hylander (Am J Phys Anthropol 64 (1984) 1–46; Am Zool 25 (1985) 315–330) demonstrated that the distribution of strains arising from wishboning loads is comprehensible with reference to the mechanics of curved beams. Theory of curved beams s…
Brief communication
Recent studies suggest a large raptor such as the crowned eagle ( Stephanaoetus coronatus ) was responsible for collecting at least a portion of the primate fauna from the South African fossil site of Taung, including its lone hominin specimen. This taphonomic signature at Taung is currently regarded as a unique and, most likely, isolated case in primate and human evolution. However, the activities of large, carnivorous birds should also be detec…
Hard-Object Feeding in Sooty Mangabeys (Cercocebus atys) and Interpretation of Early Hominin Feeding Ecology
Morphology of the dentofacial complex of early hominins has figured prominently in the inference of their dietary adaptations. Recent theoretical analysis of craniofacial morphology of Australopithecus africanus proposes that skull form in this taxon represents adaptation to feeding on large, hard objects. A modern analog for this specific dietary specialization is provided by the West African sooty mangabey, Cercocebus atys. This species habitua…
Reduced stiffness of alveolar bone in the colobine mandible
Alveolar bone has several mechanical functions, including tooth support and accommodation of occlusal and other masticatory forces. Its unique functional‐mechanical environment is reflected by its structural characteristics, but whether alveolar bone is materially distinct from bone elsewhere in the primate facial skeleton is uncertain. This uncertainty is attributable not only to a limited amount of data but also to conflicting findings among th…
Technical note
Researchers have increasingly recognized the need to quantify the material properties of primate food items, particularly hardness (H) and stiffness (E), which is measured as elastic modulus. Assessing E in the field is particularly difficult because the typical equipment needed to perform the requisite analyses is expensive and cumbersome. Alternatively, researchers can use hand-held, relatively inexpensive, portable durometers that measure H on…
Sex and age differences in the diet and ingestive behaviors of sooty mangabeys ( Cercocebus atys ) in the Tai forest, Ivory coast
Members of the Cercocebus ‐ Mandrillus clade are united by several morphological features, including expanded premolars which are argued to be associated with a preponderance of hard objects in the diet. We test the association between premolar expansion and hard object feeding by examining how different dental regions are used during food processing. We examined the diet and oral processing activities of sooty mangabeys ( Cercocebus atys ) in th…
Brief communication
The documentation of enamel thickness variation across primates is important because enamel thickness has both taxonomic and functional relevance. The Old World monkeys commonly referred to as mangabeys have figured prominently in investigations of feeding ecology and enamel thickness. In this article, we report enamel thickness values for four mangabey taxa ( Cercocebus atys , Cercocebus torquatus , Lophocebus aterrimus , and Lophocebus albigena…
Primate Feeding and Foraging
Given that something as fundamental as food acquisition is subject to selection pressure, it follows that morphological and behavioral diversity among primates is reflective of a range of adaptations to diet, feeding, and foraging. The recognition of these adaptations, however, is operationally difficult because it is the interaction between morphological and ecological variables that serves to define the particular adaptation. Researchers have a…
Focus on West Africa
Raptors and primate evolution
Most scholars agree that avoiding predators is a central concern of lemurs, monkeys, and apes. However, given uncertainties about the frequency with which primates actually become prey, the selective importance of predation in primate evolution continues to be debated. Some argue that primates are often killed by predators, while others maintain that such events are relatively rare. Some authors have contended that predation's influence on primat…
Dental wear among cercopithecid monkeys of the Taï forest, Côte d'Ivoire
Studies of dental macrowear can be useful for understanding masticatory and ingestive behavior, life history, and for inferring dietary information from the skeletal material of extinct and extant primates. Such studies to date have tended to focus on one or two teeth, potentially missing information that can be garnered through examination of wear patterns across the tooth row. Our study measured macrowear in the postcanine teeth of three sympat…
Primate Behavior and Ecology (50 works) · Biology (47 works) · Ecology (28 works) · Zoology (28 works) · Ecology (23 works) · Evolution and Paleontology Studies (18 works) · Animal Vocal Communication and Behavior (17 works) · Primate (15 works) · Evolutionary biology (14 works) · Wildlife Ecology and Conservation (14 works)