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Department of Evolutionary Anthropology
104 Biological Sciences Building
Box 90383
Durham, NC 27708-9976
(919) 684-4124  (Phone)
(919) 660-7348 (Fax)

    Ken Glander

  • Ken Glander

  • Professor
  • Evolutionary Anthropology
  • 011 Biological Sciences Building
  • Campus Box 90383
  • Phone: (919) 668-0267
  • Fax: (919) 660-7348
  • Homepage
  • Curriculum Vitae

  • Specialties

    • Primate Ecology
    • Behavioral Ecology and Physiology
    • Primate Reproduction
    • Primate Biology

  • Research Description

    My research focuses on the primate diet with four key objectives: 1) identifying what is selected from what is available and the chemical explanations for the selection; 2) characterize the behavioral and physiological adaptations of wild primates in response to their changing environmental conditions; 3) illuminating the interaction between diet and the gut microbiome; and 4) validating the relationship between primate circadian behavior and their 24-hour luminous environment. Research addressing these objectives is carried out in Costa Rica (CR) and at the Duke University Lemur Center (DLC). 
    Objective 1: Begun in 1970, my long-term field project investigating the interaction between plant-produced chemicals and primate feeding behavior as well as the impact this has on primate social organizations continues My research protocols have expanded to include: how food characteristics affect tooth wear (collaboration with Dr. Mark Teaford); understanding the functional anatomy of wild primates living in their natural habitat (collaboration with Drs. Christopher Vinyard and Susan Williams); the evolutionary development of optimal group size and composition; the relationship between food quality/quantity and body size; the factors affecting short and long-term demographic changes in established groups; and the role of regenerating forests on primate density. The study population consists of 75-100 individually marked mantled howling monkeys (Alouatta palliata) living in dry forest habitats in northwestern Costa Rica. 
    Objective 2: Basic physiology research (e.g. core body temperature, EMG, blood glucose levels, heart rate, metabolic rate) on primates has historically been limited to the laboratory. A revolution in miniaturization has allowed us to effectively utilize conventional lab-based technologies in a field setting. We are measuring the subcutaneous and core body temperatures of free-ranging monkeys. These data on internal temperatures are then related to ambient temperature at the animal’s location while documenting natural behaviors. For the same individuals, we record blood glucose levels as a measure of available energy, hormonal profiles related to temperature and energy regulation as well as dietary nutritional values. In addition, we record variation in weather conditions throughout the animals’ forest habitats during wet and dry seasons allowing us to relate this environmental variation to the behavioral and physiological data from free-ranging monkeys. By directly linking subcutaneous and core body temperature, available energy, and hormonal variation to environmental conditions in free-ranging animals, we are able to interpret primate behaviors in the context of the environmentally dictated selection pressures these animals experience. 
    Objective 3: Primates cannot digest the complex carbohydrates (leaves, bark, flowers) they consume and must rely on cellulose-digesting microbes in their gut. These microbes have cellulose-digesting abilities and play a key role in providing energy to their hosts. Microbial fermentation of plant material is a critical component for many primates, as the host alone cannot digest and extract nutrients from most plant material and all primates, including humans, consume some plant material (tarsiers are the exception). The microbial community of the gut affects many physiological characteristics of mammals, including the ability to digest and break down polysaccharides, that would otherwise be rendered indigestible The human microbiome has been extensively studied, but little is know about the nonhuman microbiome. For humans, diet is known to be a powerful predictor as well as shaper of gut microbiomes. For example, gut bacteria have been shown to be different in obese and lean humans (Bajzer & Seeley, 2006). Also, changing the proportion of ingested fats, carbohydrates, and protein can dramatically alter the functional group distribution of the gut flora and fauna. To comprehend these and other relationships in wild and captive primates, the recent advent of high-throughput metagenomics sequencing will be used to characterize their gastrointestinal microbiome. The bacterial 16S rRNA gene is analyzed to characterize the fecal microbial community structure of the mantled howling monkey in CR and lemurs at DLC. 
    Objective 4: There is a scientific debate about the photic niche (diurnal, nocturnal, crepuscular, cathemeral) of lemurs (Perry et al., 2007; Tan et al., 2008). The debate is based on observations of daily behavior patterns that is then used as indicators of evolutionary shifts (e.g., from nocturnal to diurnal activity) and has direct implications for whether the ancestral primate was nocturnal or diurnal. Compounding the debate is the conflicting data in the literature indicating that the same species occupies different photic niches. A recent study clearly suggests that the physical characteristics of light (e.g., intensity) during the night (and perhaps during the day) define whether lemurs will show, nocturnal, diurnal or cathemeral behavior (Erkert and Cramer, 2006). The debate over the evolution of lemur nychthemeral behavior specifically and that of primates in general would be much better informed by data from controlled experiments where behavior patterns were functionally related to the physical characteristics of light (intensity, duration, spectrum, timing) during the day and during the night. A collaboration with Rennselaer’s Lighting Research Center (LRC) was established to obtain a better understanding of how the light/dark cycle affects primates. The LRC is the world's leading university-based research and education organization devoted to lighting. LRC engineers built and installed a custom-built LED lighting fixture with nine separate channels of light sources [one polychromatic (white) light and eight narrow-band LED sources: 407 nm, 436 nm, 460 nm, 478 nm, 502 nm, 519 nm, 597 nm, 631 nm] at the DLC. By systematically modulating the physical characteristics of the light under controlled conditions at the DLC, we hope to establish which light regimes result in different behavior patterns, and how those relate to their natural environment, both seasonally and monthly (lunar cycle).

  • Current Projects

    Diet selection by wild primates, Physiology of free-ranging primates, Determining the effect of light on primate circadian rhythms

  • Education

      • PhD,
      • University of Chicago,
      • 1975
      • M.A.,
      • Anthropology,
      • University of Chicago,
      • 1971
      • B.A.,
      • University of Texas, Austin,
      • 1969

  • Selected Publications

      • Glander, KE.
      • 2006.
      • Average body weight for mantled howling monkeys (Alouatta pallilata): an assessment of average values and variability.
      • 247-263
      • [PDF]
      • .
      Publication Description

      A comparison of mantled howling monkey (Alouatta palliata) body weights from two Costa Rican populations at Santa Rosa (SR) and La Pacifica (LP) plus the island population of Barro Colorado (BCI) yielded average body weights of 6,445 g for BCI females (N=49), 5,161 g for SR females (N=21), and 4,726 g for LP females (N=663). Average male body weight for these same three populations was 7,562 g for BCI (N=38), 6,573 g for SR (N=15), and 5,790 g for LP (N=288). All three populations are sexually dimorphic with the males being significantly heavier than the females (BCI: F=65.71, P

      • Glander, K.E..
      • 1994.
      • Nonhuman primate self-medication with wild plant foods.
      • 227-239
      • [PDF]
      • .
      • Glander, K.E.
      • 1979.
      • Howling monkey feeding behavior and plant secondary compounds: A study of strategies.
      • 561-573
      • [PDF]
      • .
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  • Selected Grants

    • Collaborative Research: Ecological and Functional Morphology of Feeding in Free-Ranging
      • Type: Research
      • Agency: National Science Foundation
    • Collaborative Research: Ecological and Functional Morphology of Feeding in Free-Ranging Mantled Howling Monkeys
      • Type: Research
      • Agency: National Science Foundation
    • Energy Balance in Free-Ranging Lemurs
      • Type: Research
      • Agency: St. Catherines Island Research Program
    • The ecology of manatees in Mexico
      • Type: Research
      • Agency: The Mohamed bin Zayed Species Conservation Fund

  • Teaching

    • BAA 93
      • INTRO BIOLOGICAL ANTHRO
    • PRIMATOL 186S
      • INTERNSHIP PRIMATOLOGY
    • PRIMATOL 187S
      • SR SEM IN PRIMATOLOGY
    • BAA 193
      • RESEARCH INDEPENDENT STUDY
    • BAA 399
      • SPECIAL READINGS