Fred B. Bercovitch

Kyoto University, Kioto, Kyōto, Japan

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Publications (99)212.25 Total impact

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    ABSTRACT: Despite being a charismatic and well-known species, the social system of the koala (Phascolarctos cinereus-the only extant member of the family Phascolarctidae) is poorly known and much of the koala's sociality and mating behaviors remain un-quantified. We evaluated these using proximity logging-GPS enabled tracking collars on wild koalas and discuss their implications for the mating system of this species. The frequency and duration of male-female encounters increased during the breeding season, with male-male encounters quite uncommon, suggesting little direct mating competition. By comparison, female-female interactions were very common across both seasons. Body mass of males was not correlated with their interactions with females during the breeding season, although male size is associated with a variety of acoustic parameters indicating individuality. We hypothesise that vocal advertising reduces the likelihood of male-male encounters in the breeding season while increasing the rate of male-female encounters. We suggest that male mating-season bellows function to reduce physical confrontations with other males allowing them to space themselves apart, while, at the same time, attracting females. We conclude that indirect male-male competition, female mate choice, and possibly female competition, mediate sexual selection in koalas.
    PLoS ONE 07/2015; 10(7):e0130657. DOI:10.1371/journal.pone.0130657 · 3.23 Impact Factor
  • Fred B. Bercovitch · Philip S. M. Berry ·
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    ABSTRACT: Birth site location can have enormous implications for female reproductive success. Some ungulate species demonstrate consistent birth site fidelity, while others shift birth locations during their lifetimes as a function of ecological and social factors. We plotted 39 years of birth records from a wild population of Thornicroft's giraffe, Giraffa camelopardalis thornicrofti, to test the hypothesis that giraffe use consistent locations for birth. Data from 29 calves born to nine females revealed that birth seasonality was absent and that ecological zone had no significant impact on birth locations. Consecutive births by individual females were not limited to certain locations, with the distance between sequential birth sites tending to be greater if a calf failed to survive the first year of life. Our evidence conflicts with the suggestion that giraffe cows regularly return to special locations for bearing calves. We suggest that the choice of birth location is a function of nonseasonal breeding, predator pressure and extensive variation in microhabitat characteristics within ecological zones. Female giraffe have evolved a flexible reproductive strategy, whereby they regulate choice of birth site location based upon their past reproductive history, current ecological conditions (including both resource availability and predator pressure) and present social surroundings.
    African Journal of Ecology 06/2015; 53(2). DOI:10.1111/aje.12209 · 0.82 Impact Factor
  • Fred B. Bercovitch · Francois Deacon ·
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    ABSTRACT: Giraffe are popular animals to watch while on wildlife safaris, and feature prominently in zoos, advertisements, toys and cartoons. Yet, until recently, few field studies have focused on giraffe. We introduce this giraffe topic issue with a review essay that explores five primary questions: How many (sub) species of giraffe exist? What are the dynamics of giraffe herds? How do giraffe communicate? What is the role of sexual selection in giraffe reproduction? How many giraffe reside in Africa? A confluence of causes has produced drastic declines in giraffe population numbers in Africa, and we conclude that guiding giraffe conservation plans depends upon evaluation of the five key quandaries that we pose.RésuméLes girafes sont des animaux que les touristes aiment observer lors des safaris et elles tiennent une place importante dans les zoos, les publicités, les jouets et les dessins animés. Pourtant, jusqu'il y a peu, seules quelques études de terrain s’étaient intéressées à la girafe. Nous commençons cette publication sur les girafes par une analyse qui explore cinq questions fondamentales: Combien y a-t-il d'espèces (de sous-espèces) de girafes? Quelle est la dynamique des groupes de girafes? Comment les girafes communiquent-elles? Quel est le rôle de la sélection sexuelle dans la reproduction des girafes? Combien y a-t-il de girafes en Afrique? Une confluence de causes a entraîné un déclin drastique des populations de girafes en Afrique, et nous concluons que l'orientation des plans de conservation des girafes dépend de l’évaluation des cinq questions que nous soulevons.
    African Journal of Ecology 06/2015; 53(2). DOI:10.1111/aje.12222 · 0.82 Impact Factor
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    ABSTRACT: Genetic studies not only contribute substantially to our current understanding of the natural variation in behavior and health in many species, they also provide the basis of numerous in vivo models of human traits. Despite the many challenges posed by the high level of biological and social complexity, a long lifespan and difficult access in the field, genetic studies of primates are particularly rewarding because of the close evolutionary relatedness of these species to humans. The free-ranging rhesus macaque (Macaca mulatta) population on Cayo Santiago (CS), Puerto Rico, provides a unique resource in this respect because several of the abovementioned caveats are of either minor importance there, or lacking altogether, thereby allowing long-term genetic research in a primate population under constant surveillance since 1956. This review summarizes more than 40 years of genetic research carried out on CS, from early blood group typing and the genetic characterization of skeletal material via population-wide paternity testing with DNA fingerprints and short tandem repeats (STRs) to the analysis of the highly polymorphic DQB1 locus within the major histocompatibility complex (MHC). The results of the paternity studies also facilitated subsequent studies of male dominance and other factors influencing male reproductive success, of male reproductive skew, paternal kin bias, and mechanisms of paternal kin recognition. More recently, the CS macaques have been the subjects of functional genetic and gene expression analyses and have played an important role in behavioral and quantitative genetic studies. In addition, the CS colony has been used as a natural model for human adult-onset macular degeneration, glaucoma, and circadian rhythm disorder. Our review finishes off with a discussion of potential future directions of research on CS, including the transition from STRs to single nucleotide polymorphism (SNP) typing and whole genome sequencing. Am. J. Primatol.
    American Journal of Primatology 06/2015; DOI:10.1002/ajp.22424 · 2.44 Impact Factor
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    ABSTRACT: The ability to determine hormonal profiles of primate populations using non-invasive techniques can help to monitor physical fitness, stress, and physiological responses to environmental changes. We investigated fecal glucocorticoids (fGC) and DHEAS concentrations in captive Japanese macaques (Macaca fuscata) in relation to environmental, biological, and social factors. The subjects were female Japanese monkeys from 4 months to 31 years old housed in captivity (27 in social groups and 12 in single cages). Fecal samples were collected from all females, and behavioral data from the social groups during the mating season and the following birth season. Hormonal concentrations were analyzed by enzyme immunoassay. Our results revealed that both fGC and fecal DHEAS concentrations are higher in females housed indoors in single cages than in those living outdoors in social groups. We also found that fGC concentrations were higher in the cycling females during the mating (winter) season than the lactating females in the birth (spring) season. Age was negatively associated to both fGC and fecal DHEAS levels, but the relationship between age and fecal DHEAS was more evident in females housed indoors in single cages than in females housed in outdoor social groups. We did not observe any association of dominance rank with either fecal DHEAS or fGC. This study showed that measurement of fecal DHEAS and fGC can be a good method to assess stress in Japanese macaques. These findings provide insights about the physiology of these two adrenal hormones in female Japanese macaques, which can be applied to wild populations and is fundamental for captive management and conservation biology. Am. J. Primatol. © 2014 Wiley Periodicals, Inc.
    American Journal of Primatology 11/2014; 76(11). DOI:10.1002/ajp.22295 · 2.44 Impact Factor
  • Philip S. M. Berry · Fred B. Bercovitch ·
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    ABSTRACT: In cohesive social groups, travel progressions are often led by dominant or older individuals, but the leadership traits of individuals residing in flexible social systems are poorly known. Giraffe reside in herds characterized by fission–fusion dynamics frequently mediated by kinship. We analyzed 41 years (1971–2012) of longitudinal data collected from a community of Thornicroft's giraffe (Giraffa camelopardalis thornicrofti) living around South Luangwa National Park, Zambia, to assess the characteristics of herd leaders. Movement of giraffe in a single file progression was not associated with either season or time of day, but progressions were significantly more likely to occur when giraffe traveled in open areas. The oldest female in a herd was significantly more likely to be at the front position than expected, occupying the leadership niche on 79% of observations. We reason that matriarchal leadership in giraffe, as in African elephants, Loxodonta africana, is associated with resource learning. Giraffe societies are constructed on a heretofore unrecognized foundation that integrates relatedness and familiarity with matriarchal leadership in herd movement.
    African Journal of Ecology 09/2014; 53(2). DOI:10.1111/aje.12173 · 0.82 Impact Factor
  • Fred B. Bercovitch · Philip S. M. Berry ·
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    ABSTRACT: Temporary all‐male social groups are formed in a number of animal species. We examined 34 years of data collected from 36 male Thornicroft's giraffe in the Luangwa Valley, Zambia, to test a set of predictions related to five possible functions of all‐male herds (predator protection, practicing aggressive skills, prolonging life, nutritional demands and resource learning). We found that all‐male herds were significantly smaller than mixed‐sex herds, usually contained a mature bull, and were not dependent upon season or habitat. Dyadic associations between males in single sex herds were quite weak, with Keywords: Giraffa camelopardalis; association index; bachelor bands; giraffe; information transfer; resource learning Document Type: Research Article DOI: Publication date: June 1, 2015 $(document).ready(function() { var shortdescription = $(".originaldescription").text().replace(/\\&/g, '&').replace(/\\, '<').replace(/\\>/g, '>').replace(/\\t/g, ' ').replace(/\\n/g, ''); if (shortdescription.length > 350){ shortdescription = "" + shortdescription.substring(0,250) + "... more"; } $(".descriptionitem").prepend(shortdescription); $(".shortdescription a").click(function() { $(".shortdescription").hide(); $(".originaldescription").slideDown(); return false; }); }); Related content In this: publication By this: publisher In this Subject: Zoology , Ecology By this author: Bercovitch, Fred B. ; Berry, Philip S. M. GA_googleFillSlot("Horizontal_banner_bottom");
    African Journal of Ecology 08/2014; 53(2). DOI:10.1111/aje.12169 · 0.82 Impact Factor

  • IPS XXV Congress, Hanoi, Vietnam; 08/2014
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  • Journal of Zoo and Wildlife Medicine 12/2013; 44(4):466-466. · 0.42 Impact Factor
  • F. B. Bercovitch · P. S. M. Berry ·
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    ABSTRACT: In many mammalian species, animals form subunits within larger groups that are often associated with kinship and/or age proximity. Kinship mediates fission/fusion social dynamics of giraffe herds, but the role of age proximity has been unexamined. Here, we analyze 34 years of data from a population of Thornicroft's giraffe, Giraffa camelopardalis thornicroftii, living in Zambia in order to assess the extent to which age proximity influences herd composition. We show for the first time that calves born into the same cohort have stronger social associations than calves born into different age cohorts, and that the strength of their association is independent of the strength of maternal associations. Duration of time co-resident in the population did not influence the strength of social associations. Mothers and adult daughters have significantly stronger social associations than do unrelated adult females. We suggest that giraffe have evolved mechanisms for fostering the formation of social associations with similar aged non-kin. Giraffes live in a complex society incorporating both kinship and age proximity as factors modulating the formation of social associations that underlie the fission/fusion dynamics of their flexible herd structure.
    Journal of Zoology 08/2013; 290(4). DOI:10.1111/jzo.12039 · 1.88 Impact Factor
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    ABSTRACT: Dehydroepiandrosterone (DHEA) and its sulfate, DHEAS, are the most abundant steroid hormones in primates, providing a large reservoir of precursors for the production of androgens. DHEAS levels decline with age in adult humans and nonhuman primates, prompting its consideration as a biomarker of senescence. However, the mechanisms responsible for this age-related decrease and its relationship to reproduction remain elusive. This research investigated DHEAS concentrations in fecal samples in order to determine age-related changes in captive Japanese macaques, as well as to assess the possible influence of seasonality. The subjects were 25 female Japanese macaques (2 weeks to 14 years-old) housed outdoors in social groups at the Primate Research Institute. We collected three fecal samples from each animal during the breeding season (October to December) and three additional samples from adult females during the non-breeding season (May to June). The hormonal concentrations were determined using enzyme immunoassay. DHEAS concentration was negatively correlated with age, but we did not find a significant difference between breeding and non-breeding seasons. Neonatal macaques had the highest DHEAS concentrations of all age groups. We suggest that elevated neonatal DHEAS is possibly a residue from fetal adrenal secretion and that, as in humans, it might assist in neurobiological development.
    General and Comparative Endocrinology 06/2013; 191. DOI:10.1016/j.ygcen.2013.05.019 · 2.47 Impact Factor
  • Fred B. Bercovitch · Philip S. M. Berry ·
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    ABSTRACT: A variety of social systems have evolved as a consequence of competition and cooperation among individuals. Giraffe (Giraffa camelopardalis sp.) societies are an anomaly because the dearth of long-term data has produced two polar perspectives: a loose amalgamation of non-bonded individuals that sometimes coalesce into a herd and a structured social system with a fission-fusion process modifying herd composition within a community. We analysed 34 years of data collected from a population of Thornicroft's giraffe (G. c. thornicrofti, Lydekker 1911) residing in South Luangwa, Zambia, to establish the nature of giraffe society. Our sample consisted of 52 individually recognized animals. We found that giraffe herd composition is based upon long-term social associations that often reflect kinship, with close relatives significantly more likely than non-relatives to establish herds. Mother/offspring dyads had the strongest associations, which persisted for years. Giraffe live in a complex society characterized by marked flexibility in herd size, with about 25% of the variance in herd composition owing to kinship and sex. We suggest that giraffe herds share many characteristics of fission-fusion social systems and propose that sophisticated communication systems are a crucial component regulating subgroup dynamics.
    African Journal of Ecology 06/2013; 51(2). DOI:10.1111/aje.12024 · 0.82 Impact Factor
  • Fred B. Bercovitch ·

    African Journal of Ecology 06/2013; 51(2). DOI:10.1111/aje.12016 · 0.82 Impact Factor
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    ABSTRACT: In principle, conservation planning relies on long-term data; in reality, conservation decisions are apt to be based upon limited data and short-range goals. For the koala (Phascolarctos cinereus), frequently reliance is made on the assumption that indirect signs can be used to indicate behavioural preferences, such as diet choice. We examined the relationship between the use of trees by koalas and the presence of scats beneath those trees. Tree use was associated with scat presence on 49% of occasions when koalas were radio-tracked in both central Queensland (n = 10 koalas) and south-east Queensland (n = 5 koalas), increasing to 77% of occasions when trees were rechecked the following day. Koala densities were correlated with scat abundance at sites with koala density between ~0.2 and 0.6 koalas per hectare. Our results confirm that scat searches are imprecise indicators of tree use by koalas, but demonstrate that these searches can be used, with caveats, to estimate koala population densities. We discuss how errors in estimating or applying predictive model parameters can bias estimates of occupancy and show how a failure to validate adequately the assumptions used in modelling and mapping can undermine the power of the products to direct rational conservation and management efforts.
    Australian Mammalogy 03/2013; 35(2). DOI:10.1071/AM12023 · 0.83 Impact Factor
  • Fred B. Bercovitch ·

    International Journal of Primatology 12/2012; 33(6). DOI:10.1007/s10764-012-9639-7 · 1.99 Impact Factor
  • Fred B. Bercovitch ·

    Primates 10/2012; 53(4). DOI:10.1007/s10329-012-0314-6 · 1.34 Impact Factor
  • P. S. M. Berry · F. B. Bercovitch · Andrew Kitchener ·
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    ABSTRACT: Much of the information available about the life history of the giraffe, Giraffa camelopardalis, is derived from captive studies or short‐term field studies. The coat colour of male giraffes, especially the blotches, darkens with age, but no studies have systematically mapped the colour transition with chronological age based on long‐term data. We examine the value of using darkening coat colour as a biomarker of male age. We analyzed 33 years of data from 36 male Thornicroft's giraffes, G. c. thornicroftii, living in Zambia in order to document key milestones in male development. We found that the change in male pelage colouration takes an average of 1.8 years and that males are completely covered with coal‐black blotches at an average age of 9.4 years. Using lifetime data on male deaths and disappearances, combined with cross‐sectional records on coat‐colour transformation, we conclude that the average age of death among male giraffes is about 16 years old. The maximum lifespan of male giraffes is about 22 years compared with a maximum lifespan of about 28 years for female giraffes. We conclude that the possible proximate mechanisms and adaptive significance of male coat‐colour changes should be studied in more detail.
    Journal of Zoology 07/2012; 287(3). DOI:10.1111/j.1469-7998.2012.00904.x · 1.88 Impact Factor
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    ABSTRACT: Island populations of animals are expected to show reduced genetic variation and increased incidence of inbreeding because of founder effects and the susceptibility of small populations to the effects of genetic drift. Koalas (Phascolarctos cinereus) occur naturally in a patchy distribution across much of the eastern Australian mainland and on a small number of islands near the Australian coast. We compared the genetic diversity of the naturally occurring population of koalas on North Stradbroke Island in south-east Queensland with other island populations including the introduced group on St Bees Island in central Queensland. The population on St Bees Island shows higher diversity (allelic richness 4.1, He = 0.67) than the North Stradbroke Island population (allelic richness 3.2, He = 0.55). Koalas on Brampton, Newry and Rabbit Islands possessed microsatellite alleles that were not identified from St Bees Island koalas, indicating that it is most unlikely that these populations were established by a sole secondary introduction from St Bees Island. Mitochondrial haplotypes on the central Queensland islands were more similar to a haplotype found at Springsure in central Queensland and the inland clades in southeast Queensland, rather than the coastal clade in south-east Queensland.
    Australian Journal of Zoology 01/2012; 60(5):303. DOI:10.1071/ZO12075 · 0.94 Impact Factor
  • Fred B. Bercovitch ·

    Biodiversity 12/2011; 8(3):33-37. DOI:10.1080/14888386.2007.9712827

Publication Stats

3k Citations
212.25 Total Impact Points


  • 2011-2015
    • Kyoto University
      • Primate Research Institute
      Kioto, Kyōto, Japan
  • 2010
    • University of Queensland
      • Centre for Mined Land Rehabilitation
      Brisbane, Queensland, Australia
  • 2003-2010
    • San Diego Zoo
      San Diego, California, United States
  • 1991-2005
    • American University in Puerto Rico
      • Caribbean Primate Research Center
      Rio Rico, Arizona, United States
  • 2002
    • Center for Advanced Studies on Puerto Rico and the Caribbean
      Sabana Seca, Toa Baja, Puerto Rico
  • 1987-2002
    • Wisconsin National Primate Research Center
      Madison, Wisconsin, United States
  • 1993-1998
    • University of Puerto Rico, Medical Sciences Campus
      San Juan, San Juan, Puerto Rico
    • Humboldt-Universität zu Berlin
      • Department of Biology
      Berlín, Berlin, Germany
  • 1995
    • Harvard University
      • Department of Psychology
      Cambridge, Massachusetts, United States
  • 1992-1995
    • University of Puerto Rico at Ponce
      Ponce, Ponce, Puerto Rico
  • 1986-1992
    • University of Wisconsin–Madison
      • • Wisconsin National Primate Research Center
      • • Department of Psychology
      Madison, Wisconsin, United States