Han De Vries

Han De Vries
Utrecht University | UU · Department of Animal Ecology

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About

170
Publications
53,120
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7,322
Citations
Citations since 2016
10 Research Items
2501 Citations
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
Introduction
Han De Vries has worked at the Department of Animal Ecology, Utrecht University. Han did research in Animal Communications and Biostatistics. Their most recent publication is 'Female social behaviour during three male introductions in captive groups of rhesus macaques'.

Publications

Publications (170)
Article
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Emotional bookkeeping is the process by which primates integrate the emotional effects of social interactions to form internal representations of their affiliative relationships. The dynamics and speed of this process, which comprises the formation, maintenance and fading out of affiliative relationships, are not clear. Empirical data suggest that...
Article
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Access to limited resources may be achieved by dominance as well as by high rates of aggressive and affiliative behaviour. We investigated the relative effectiveness of dominance rank and aggressive and affiliative behaviour in accessing three material and three social resources. Aggressive and affiliative behaviour of 24 female long-tailed macaque...
Article
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Housing primates in naturalistic groups provides social benefits relative to solitary housing. However, food intake may vary across individuals, possibly resulting in overweight and underweight individuals. Information on relative adiposity (the amount of fat tissue relative to body weight) is needed to monitor overweight and underweight of group-h...
Article
Introductions of new males into captive primate groups are often necessary to prevent inbreeding, but also bear high social risks. To minimize these risks, it is crucial to understand the social behaviour accompanying male introductions. While the behaviour of new males is generally understood, information on resident female behaviour during introd...
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Captive chimpanzees regularly show abnormal behaviour, including regurgitation and reingestion (R/R). R/R may have several causes, among them a suboptimal diet. For this reason, the effect of a diet change towards a more fibre-rich diet on R/R was studied in the Amersfoort Zoo chimpanzee group comprising 15 individuals. In addition, the relationshi...
Article
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Relatedness is likely to affect the decisions of animals regarding their affiliations with conspecifics. Social network analysis provides tools to describe the social structure of animals. Here, we investigate the social network of a population of 27 unmanaged Konik horses in the Blauwe Kamer Nature Reserve, in the Netherlands. We test three hypoth...
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Whether and how primates are able to maintain long-term affiliative relationships is still under debate. Emotional bookkeeping (EB), the partner-specific accumulation of emotional responses to earlier interactions, is a candidate mechanism that does not require high cognitive abilities. EB is difficult to study in real animals, due to the complexit...
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A dominance hierarchy is an important feature of the social organisation of group living animals. Although formal and/or agonistic dominance has been found in captive wolves and free-ranging dogs, applicability of the dominance concept in domestic dogs is highly debated, and quantitative data are scarce. Therefore, we investigated 7 body postures a...
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Although tactical deception (TD) may be employed to hide sexual behaviour, there is as yet no firm evidence for it. Hiding may be guided by cognitive mechanisms consistent with either no, low or high level TD, such as exploiting male peripheral positions (no TD), creating distance (TD level 1) or hiding behind screens (TD level 1.5 which involves v...
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Primate affiliative relationships are differentiated, individual-specific and often reciprocal. However, the required cognitive abilities are still under debate. Recently, we introduced the EMO-model, in which two emotional dimensions regulate social behaviour: anxiety-FEAR and satisfaction-LIKE. Emotional bookkeeping is modelled by providing each...
Article
Full-text available
A dominance hierarchy is an important feature of the social organisation of group living animals. Although formal and/or agonistic dominance has been found in captive wolves and free-ranging dogs, applicability of the dominance concept in domestic dogs is highly debated, and quantitative data are scarce. Therefore, we investigated 7 body postures a...
Article
Full-text available
Hundreds of rehabilitant great apes have been released into the wild, and thousands await release. However, survival rates after release can be as low as 20 %. Several factors influence individuals' survival rates, one of which is the capacity to obtain an adequate diet once released. Released individuals are faced with a mixture of familiar and no...
Article
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Agent-based models provide a promising tool to investigate the relationship between individuals' behavior and emerging group-level patterns. An individual's behavior may be regulated by its emotional state and its interaction history with specific individuals. Emotional bookkeeping is a candidate mechanism to keep track of received benefits from sp...
Article
To find a dominance order most consistent with a linear hierarchy, the I&SI method minimizes two criteria: first the number of inconsistencies I (i.e. number of dyads in which the lower-ranked individual dominates the higher-ranked one) and then (without increasing I) the total strength of inconsistencies SI (i.e. the sum of rank differences betwee...
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In nonhuman primate social groups, dominance ranks are usually assigned to individuals based on outcomes of dyadic agonistic encounters. Multiple approaches have been used, but currently there is no consensus. One approach, David's Scores (DS), offers dual advantages of yielding cardinal scores that may in turn be used to compute hierarchical steep...
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One of the most apparent discontinuities between non-human primate (primate) call communication and human speech concerns repertoire size. The former is essentially fixed to a limited number of innate calls, while the latter essentially consists of numerous learned components. Consequently, primates are thought to lack laryngeal control required to...
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The diet of great apes consists of several hundred plant species. The factors determining diet differences have been examined between populations but not within a popu-lation, probably due to the confounding effect of seasonal fluctuations on fruit availability. In Sumatran orangutans (Pongo abelii), fruit availability appears to be sufficiently hi...
Article
Sexual competition is highly prevalent within multi-male multi-female primate groups and may lead to copulations in absence of potentially interfering bystanders. Such avoidance of bystanders may result from tactical deception or from simpler mechanisms such as taking advantage of encountered situations without bystanders, operant conditioning or a...
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In social animals an individual’s fitness depends partly on the quality of relationships with others. Qualitative variation in relationships has been conceptualized according to a three-dimensional structure, consisting of relationship value, compatibility, and security. However, the determinants of the components and their temporal stability are n...
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Next to predator detection, primate vigilance also serves to keep track of relevant conspecifics. The degree of vigilance towards group members often reflects the dominance rank of an individual: subordinates pay attention to dominants. Although it has been suggested that subordinates' vigilance may result in spatial centrality of dominants, this h...
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We examined the distribution of support behaviour within a captive group of bonobos. Most support was evoked by inter-sexual conflicts with the two highest ranking females. Within a dyad, the usual winner was most often supported. Individuals that challenged the rank order by aggressions and pestering were aggressed more often by their targets in t...
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Meat-eating is an important aspect of human evolution, but how meat became a substantial component of the human diet is still poorly understood. Meat-eating in our closest relatives, the great apes, may provide insight into the emergence of this trait, but most existing data are for chimpanzees. We report 3 rare cases of meat-eating of slow lorises...
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The construction of nests (or beds) for sleeping is a chimpanzee universal, yet little is known about the adaptive function of nest-building. We present an in-depth study of nest-building by unhabituated chimpanzees at the Seringbara study site in the Nimba Mountains, Guinea, West Africa. We recorded 1520 chimpanzee nests over 28 mo during three st...
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Monkey alarm calls have shown that in the primate clade, combinatorial rules in acoustic communication are not exclusive to humans. A recent hypothesis suggests that the number of different call combinations in monkeys increases with increased number of predator species. However, the existence of combinatorial rules in great ape alarm calls remains...
Data
Centrality of dominants in the avoidance with fleeing-control model. This graph shows the relationship between an individual's dominance strength (myDOM) and its centrality (distance to the arithmetic center of the group in meters) for the avoidance with fleeing-control model (with different combinations of AV_DOM_DIFF (vertically, 0.2–0.4) and AV_...
Data
Group spread in the fleeing model with different values for fleeing distance. This graph shows the group spread (in meters) in the fleeing model for a range of values of FleeD (x-axis, 1–20 m). Boxplots show values of 10 simulation runs, averaged over time. (TIF)
Data
Encounter structure in the fleeing model with different values for fleeing distance. This figure shows the distribution and direction of encounters among the individuals of a group for the fleeing model with different values of FleeD (horizontally, 1–20 m). Encounters are directed from initiators (y-axis) to targets (x-axis), both are ordered by do...
Data
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Centrality of dominants as a model artifact. (PDF)
Data
Group spread in the velocity model. This graph shows the group spread (in meters) in the velocity model for a range of values of MAX_VELOCITY (x-axis, 1–30 m/s). Boxplots show values of 50 simulation runs, averaged over time. (TIF)
Data
Group spread in the fleeing model with different maximum turning angle. This graph shows the group spread (in meters) in the fleeing model for a range of values for the maximum turning angle, used in the random walk procedure (x-axis, 180–90 degrees). Boxplots show values of 10 simulation runs, averaged over time. (TIF)
Data
Centrality of dominants for maximum turning angle of 45 degrees. This figure shows the relationship between an individual's dominance strength (myDOM) and its centrality (distance to the arithmetic center of the group in meters) for different models with a maximum turning angle of 45 degrees, as used in the random walk procedure. (A) Fleeing model....
Data
Encounter structure in the probabilistic avoidance model with slope 30. This figure shows the distribution and direction of encounters among the individuals of a group for the avoidance model with probabilistic avoidance with a slope of 30 for the avoidance chance function (with different combinations of AV_DOM_DIFF (vertically, 0.2–0.4) and AV_DIS...
Data
Centrality of dominants in the probabilistic avoidance model with slope 30. This figure shows the relationship between an individual's dominance strength (myDOM) and its centrality (distance to the arithmetic center of the group in meters) for the avoidance model with probabilistic avoidance with a slope of 30 for the avoidance chance function (wit...
Data
Encounter structure in the probabilistic avoidance model with slope 5. This figure shows the distribution and direction of encounters among the individuals of a group for the avoidance model with probabilistic avoidance with a slope of 30 for the avoidance chance function (with different combinations of AV_DOM_DIFF (vertically, 0.2–0.4) and AV_DIST...
Data
Snapshots of the socio-spatial group structure without restriction of fission. This figure shows snapshots of the spatial composition of the group members for different models in which the restriction of the maximum group spread was switched off. (A) Fleeing model. (B) Avoidance model (with different combinations of AV_DOM_DIFF (vertically, 0.2–0.4...
Data
Centrality of dominants in the fleeing model with different values for fleeing distance. This graph shows the relationship between an individual's dominance strength (myDOM) and its centrality (distance to the arithmetic center of the group in meters) for the fleeing model with different values of FleeD (horizontally, 1–20 m). Small distances to th...
Data
Full-text available
Win chance function and the distribution of fights among group members. (PDF)
Article
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In group-living animals, such as primates, the average spatial group structure often reflects the dominance hierarchy, with central dominants and peripheral subordinates. This central-peripheral group structure can arise by self-organization as a result of subordinates fleeing from dominants after losing a fight. However, in real primates, subordin...
Article
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Recollecting the what-where-when of an episode, or episodic-like memory, has been established in corvids and rodents. In humans, a linkage between remembering the past and imagining the future has been recognised. While chimpanzees can plan for the future, their episodic-like memory has hardly been investigated. We tested chimpanzees (Pan troglodyt...
Article
Previous studies that operationalized reactive aggression using behavioral observations in general populations have not taken into account the type of stimulus that elicits reactive aggression. In the present study we define a specific form of reactive aggression, i.e., reactive aggression in response to neutral behavior of a peer, which we will ca...
Article
Violence was shown to be qualitatively different from functional hyper-aggression in mice selected for high aggression namely Short Attack Latency (SAL), Turku Aggressive (TA) and North Carolina (NC900) strains. This study aimed at investigating whether this adulthood violent phenotype as seen previously in the SAL mice is fixed and hence behaviora...
Article
Several quantitative models of coalition formation assume that a coalition is successful if the strength of the coalition is greater than the strength of the target, but unsuccessful otherwise. However, strong empirical evidence in favour of this hypothesis is still lacking. In this study, we provide an empirical test of this assumption in Barbary...
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For managers of captive populations it is important to know whether their management provides a species with the physical and social environment that maximizes its survivorship. To determine this, survivorship comparisons with wild populations and long-term evaluations of captive populations are important. Here we provide both for orangutans. We sh...
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This article describes two health care interventions developed to support parents whose infant cries excessively. Intervention 1 consists of advice to caregivers to bring about regularity and uniformity in daily infant care and to reduce external stimuli. Intervention 2 is the same advice accompanied by instructions to swaddle during sleep. Nurses...
Article
Recently, the DomWorld model was used to evaluate five dominance ranking methods. The suitability of the DomWorld model for this purpose is however not without question. The characteristic unidirectionality of most dominance behaviour observed in many monkey species is not found in DomWorld. Besides this, the current paper shows that the additive d...
Article
Social dynamics and maintenance of social cohesion were studied by analysing social interventions in two groups of horses consisting of adult mares, their offspring, adult geldings and sub-adults. The animals were observed for a total of 1316 h. All relevant dyadic and triadic social interactions, including initial behaviour, possible intervention...
Article
Great ape life-history data are especially relevant for tests of the predictions of life-history theory and to establish firmly the derived features of human life history and therefore the changes that took place during hominin evolution. This chapter compares what is known about life history data on Sumatran and Bornean orangutans. The results ind...
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The present study aims at delineating violence from aggression, using genetically selected high (SAL, TA, NC900) and low (LAL, TNA NC100) aggressive mouse strains. Unlike aggression, violence lacks intrinsic control, environmental constraints as well as functional endpoints. Conventional measures namely latency, frequency and duration were used ini...
Article
Recent reviews on the validity of rodent aggression models for human violence have addressed the dimension of pathological, maladaptive, violent forms of aggression in male rodent aggressive behaviour. Among the neurobiological mechanisms proposed for the regulation of aggressive behaviour in its normal and pathological forms, serotonin plays a maj...
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Geographic variation in primate vocalizations has been described at two levels. First, at the level of acoustic variation within the same call type between populations and, second, at the level of presence or absence of certain call types in different populations. Acoustic variation is of interest because there are several factors that can explain...
Article
Various researchers distinguished two categories of aggressive behaviour, namely reactive and proactive aggression. Reactive aggression is an aggressive response to a perceived threat or provocation, whereas proactive aggression is behaviour that anticipates a reward. In the present study, including both a sample of disruptive behaviour disordered...
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Bonobos have a reputation as a female-dominated and egalitarian species. We examined the 2 aspects of dominance in 6 captive bonobo groups. Females do not consistently evoke submission from all males in all contexts. Though females occupy the highest-ranking positions in the dominance hierarchy, there are in each group males that obtain rather high...
Article
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The nighttime sky is increasingly illuminated by artificial light sources. Although this ecological light pollution is damaging ecosystems throughout the world, the topic has received relatively little attention. Many nocturnally migrating birds die or lose a large amount of their energy reserves during migration as a result of encountering artific...
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We studied sex differences in the nature of aggression and dominance behaviour in two newly formed groups of 1-year-old Icelandic horses. One herd contained nine geldings, the other nine mares. The groups were matched with regard to dominance-determining traits such as age, weaning age, composition of native herd, social experience, genetic origin,...
Article
Primates resolve conflicts through post-conflict interactions (PCI). However, the occurrence of different PCI in relation to one another is not well understood. Furthermore, the factors influencing the occurrence of PCI are rarely addressed together, and thereby their relative impact is usually ignored. We investigated the occurrence and interrelat...
Article
Reliable and valid phenotyping is crucial for our study of genetic factors underlying aggression in Golden Retriever dogs. A mail questionnaire based on the Canine Behavioral Assessment and Research Questionnaire (CBARQ; Hsu and Serpell, 2003, JAVMA 223(9):1293-1300) was used to assess behavioral phenotypes. Owners of 228 Golden Retrievers complete...
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Based on previous research in captivity, bonobos, Pan paniscus, have been called a female-bonded species. However, genetic and behavioural data indicate that wild females migrate. Bonding between these unrelated females would then be in contradiction with socio-ecological models. It has been argued that female bonding has been overemphasized in cap...
Article
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Primates give alarm calls in response to the presence of predators. In some species, such as the Thomas langur (Presbytis thomasi), males only emit alarm calls if there is an audience. An unanswered question is whether the audience's behaviour influences how long the male will continue his alarm calling. We tested three hypotheses that might explai...
Article
In the analysis of social dominance in groups of animals, linearity has been used by many researchers as the main structural characteristic of a dominance hierarchy. In this paper we propose, alongside linearity, a quantitative measure for another property of a dominance hierarchy, namely its steepness. Steepness of a hierarchy is defined here as t...
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The stingless bee Melipona bicolor is facultatively polygynous, a unique character among the bees. Polygynous colonies were not more productive than monogynous colonies. During the process of provisioning and oviposition of cells (POP) a queen may be either alone or together with one or two other queens. If together, each queen has on average the s...
Article
Female mammals may exert choice for mates directly by mating selectively. Alternatively, females can mate promiscuously, allowing sperm competition and/or cryptic female choice to operate. Primate sexual behaviour is probably a compromise between conflicting male and female interests, so it may be important to examine female mating behaviour indepe...
Article
In females of several mammalian species, it is becoming evident that benefits related to high dominance rank can result in increased fitness, albeit to a lesser degree than in males. We examined indicators of fitness in relation to dominance rank in a group of adult female American bison in semifree-ranging conditions. A significantly linear domina...
Article
Biological market models explain variability in reciprocity and interchange between groups. In groups with a shallow dominance gradient, grooming will be mostly exchanged for itself (i.e. exchange will occur). In groups with steep dominance hierarchies, interchange is expected: individuals will groom higher ranking individuals to get access to limi...
Article
It has been suggested that peering behavior in bonobos is a formal signal acknowledging social dominance status. We investigated whether peering meets the published criteria for a formal signal of subordination in five captive groups of bonobos. The degree of linearity in the set of peering relationships was significantly high in all study groups,...
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The clinical population of aggressive children diagnosed as having an oppositional defiant disorder (ODD) or a conduct disorder (CD) is heterogeneous, both with respect to behaviour and aetiology. Recently, the following distinction has been proposed that might further clarify this heterogeneity: reactive aggression is an aggressive response to a p...
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There are many procedures, of varying complexity, for ranking the members of a social group in a dominance hierarchy. Roughly, two types of method can be distinguished, one in which the dominance matrix is reorganized such that some numerical criterion, calculated for the matrix as a whole, is minimized or maximized, and one that aims to provide a...
Article
Individual and contextual differences in male loud calls of wild Thomas langurs (Presbytis thomasi) were studied in northern Sumatra, Indonesia. Loud calls were given in the following contexts: morning calls, vocal responses to other groups, between-group encounter calls and alarmcalls. Loud call spectrograms were analysed for a large number of var...
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De Vries and Biesmeijer described in 1998 an individual-oriented model that simulates the collective foraging behaviour of a colony of honeybees. Here we report how this model has been expanded and show how, through self-organization, three colony-level phenomena can emerge: symmetry breaking, cross inhibition and the equal harvest-rate distributio...
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In a mixed-sex, captive group of hamadryas baboons (Papio hamadryas hamadryas) we investigated whether female grooming relationships are affected by their dominance ranks. Seyfarth's [1977] grooming for support model and Barrett et al.'s [1999] biological market model both predict that in primate groups where competition for monopolizable resources...