Primates got personality,too: Toward an integrative primatology of consistent individual differences in behavior

In recent years, research on animal personality has exploded within the field of behavioral ecology. Consistent individual differences in behavior exist in a wide range of species, and these differences can have fitness consequences and influence several aspects of a species' ecology. In comparison to studies of other animals, however, there has been relatively little research on the behavioral ecology of primate personality. This is surprising given the large body of research within psychology and biomedicine showing that primate personality traits are heritable and linked to health and life history outcomes. In this article, I bring together theoretical perspectives on the ecology and evolution of animal personality with an integrative review of what we know about primate personality from studies conducted on captive, free‐ranging, and wild primates. Incorporating frameworks that emphasize consistency in behavior into primate behavioral ecology research holds promise for improving our understanding of primate behavioral evolution.     

Does an Oblique/Slanted Perspective during Virtual Navigation Engage Both Egocentric and Allocentric Brain Strategies?

Perspective (route or survey) during the encoding of spatial information can influence recall and navigation performance. In our experiment we investigated a third type of perspective, which is a slanted view. This slanted perspective is a compromise between route and survey perspectives, offering both information about landmarks as in route perspective and geometric information as in survey perspective. We hypothesized that the use of slanted perspective would allow the brain to use either egocentric or allocentric strategies during storage and recall. Twenty-six subjects were scanned (3-Tesla fMRI) during the encoding of a path (40-s navigation movie within a virtual city). They were given the task of encoding a segment of travel in the virtual city and of subsequent shortcut-finding for each perspective: route, slanted and survey. The analysis of the behavioral data revealed that perspective influenced response accuracy, with significantly more correct responses for slanted and survey perspectives than for route perspective. Comparisons of brain activation with route, slanted, and survey perspectives suggested that slanted and survey perspectives share common brain activity in the left lingual and fusiform gyri and lead to very similar behavioral performance. Slanted perspective was also associated with similar activation to route perspective during encoding in the right middle occipital gyrus. Furthermore, slanted perspective induced intermediate patterns of activation (in between route and survey) in some brain areas, such as the right lingual and fusiform gyri. Our results suggest that the slanted perspective may be considered as a hybrid perspective. This result offers the first empirical support for the choice to present the slanted perspective in many navigational aids.     

Focal vs. fecal: Seasonal variation in the diet of wild vervet monkeys from observational and DNA metabarcoding data

Assessing the diet of wild animals reveals valuable information about their ecology and trophic relationships that may help elucidate dynamic interactions in ecosystems and forecast responses to environmental changes. Advances in molecular biology provide valuable research tools in this field. However, comparative empirical research is still required to highlight strengths and potential biases of different approaches. Therefore, this study compares environmental DNA and observational methods for the same study population and sampling duration. We employed DNA metabarcoding assays targeting plant and arthropod diet items in 823 fecal samples collected over 12 months in a wild population of an omnivorous primate, the vervet monkey (Chlorocebus pygerythrus). DNA metabarcoding data were subsequently compared to direct observations. We observed the same seasonal patterns of plant consumption with both methods; however, DNA metabarcoding showed considerably greater taxonomic coverage and resolution compared to observations, mostly due to the construction of a local plant DNA database. We found a strong effect of season on variation in plant consumption largely shaped by the dry and wet seasons. The seasonal effect on arthropod consumption was weaker, but feeding on arthropods was more frequent in spring and summer, showing overall that vervets adapt their diet according to available resources. The DNA metabarcoding assay outperformed also direct observations of arthropod consumption in both taxonomic coverage and resolution. Combining traditional techniques and DNA metabarcoding data can therefore not only provide enhanced assessments of complex diets and trophic interactions to the benefit of wildlife conservationists and managers but also opens new perspectives for behavioral ecologists studying whether diet variation in social species is induced by environmental differences or might reflect selective foraging behaviors.     

Distribution of variation over populations

Understanding the significance of the distribution of genetic or phenotypic variation over populations is one of the central concerns of population genetic and ecological research. The import of the research decisively depends on the measures that are applied to assess the amount of variation residing within and between populations. Common approaches can be classified under two perspectives: differentiation and apportionment. While the former focuses on differences (distances) in trait distribution between populations, the latter considers the division of the overall trait variation among populations. Particularly when multiple populations are studied, the apportionment perspective is usually given preference (via F _ST/G _ST indices), even though the other perspective is also relevant. The differences between the two perspectives as well as their joint conceptual basis can be exposed by referring them to the association between trait states and population affiliations. It is demonstrated that the two directions, association of population affiliation with trait state and of trait state with population affiliation, reflect the differentiation and the apportionment perspective, respectively. When combining both perspectives and applying the suggested measure of association, new and efficient methods of analysis result, as is outlined for population genetic processes. In conclusion, the association approach to an analysis of the distribution of trait variation over populations resolves problems that are frequently encountered with the apportionment perspective and its commonly applied measures in both population genetics and ecology, suggesting new and more comprehensive methods of analysis that include patterns of differentiation and apportionment.     

Correlates of Research Effort in Carnivores: Body Size,Range Size and Diet Matter

Given the budgetary restrictions on scientific research and the increasing need to better inform conservation actions, it is important to identify the patterns and causes of biases in research effort. We combine bibliometric information from a literature review of almost 16,500 peer-reviewed publications on a well-known group of 286 species, the Order Carnivora, with global datasets on species'' life history and ecological traits to explore patterns in research effort. Our study explores how species'' characteristics influenced the degree to which they were studied (measured as the number of publications). We identified a wide variation in intensity of research effort at both Family and Species levels, with some of the least studied being those which may need protection in future. Our findings hint at the complex role of human perspectives in setting research agendas. We found that better-studied species tended to be large-bodied and have a large geographic range whilst omnivory had a negative relationship with research effort. IUCN threat status did not exhibit a strong relationship with research effort which suggests that the conservation needs of individual species are not major drivers of research interest. This work is the first to use a combination of bibliometric analysis and biological data to quantify and interpret gaps in research knowledge across an entire Order. Our results could be combined with other resources, such as Biodiversity Action Plans, to prioritise and co-ordinate future research effort, whilst our methods can be applied across many scientific disciplines to describe knowledge gaps.     

Laboratory Research on Behavioral Interactions as Generators of Population Phenomena in Rodents

Many population phenomena are driven by the behavior of individualanimals. The effects of behavior on differential reproductionvary with the mating system and with ecological factors; understandingof the complex interactions requires both laboratory and fieldresearch. Ecologically-relevant laboratory research should bedesigned using generalizable behavioral patterns with animalsof appropriate species, meaningful genotypes, and known earlyexperience that are studied in carefully-designed situations.Three exemplars of research of potential relevance to populationphenomena are discussed. Studies of dominance and differentialreproduction in deer mice in seminatural enclosures suggestthat dominant males make disproportionately large contributionsto gene pools and that dominance may be heritable. Laboratorystudies of reproductive function in individuals bearing differentalleles, determined electrophoretically, appear relevant topopulation processes reported correlated with changes in genefrequencies at these loci. Patterns of mate choice in two speciesof Microtus may be important in generating their contrastingmating systems in the field. Well-designed laboratory researchcan help reveal behavioral processes critical to populationphenomena.     

The Ontogeny of Social Behavior and Body Coloration in the African Cichlid Fish Haplochromis burtoni

The ontogeny of behavioral patterns and body coloration are described for the African cichlid fish, Haplochromis burtoni. The development of particular color patterns correlates directly with appearance of behavioral patterns which “use” those color patterns. There is a flexible timetable associated with these events which depends on both social and environmental factors.     

Life History Trade-Offs and Behavioral Sensitivity to Testosterone: An Experimental Test When Female Aggression and Maternal Care Co-Occur

Research on male animals suggests that the hormone testosterone plays a central role in mediating the trade-off between mating effort and parental effort. However, the direct links between testosterone, intrasexual aggression and parental care are remarkably mixed across species. Previous attempts to reconcile these patterns suggest that selection favors behavioral insensitivity to testosterone when paternal care is essential to reproductive success and when breeding seasons are especially short. Females also secrete testosterone, though the degree to which similar testosterone-mediated trade-offs occur in females is much less clear. Here, I ask whether testosterone mediates trade-offs between aggression and incubation in females, and whether patterns of female sensitivity to testosterone relate to female life history, as is often the case in males. I experimentally elevated testosterone in free-living, incubating female tree swallows (Tachycineta bicolor), a songbird with a short breeding season during which female incubation and intrasexual aggression are both essential to female reproductive success. Testosterone-treated females showed significantly elevated aggression, reduced incubation temperatures, and reduced hatching success, relative to controls. Thus, prolonged testosterone elevation during incubation was detrimental to reproductive success, but females nonetheless showed behavioral sensitivity to testosterone. These findings suggest that the relative importance of both mating effort and parental effort may be central to understanding patterns of behavioral sensitivity in both sexes.     

Behavioral adaptations to parasites: an ethological approach.

Wild vertebrate animals must live in an environment with the ever present threat of internal and external parasites. This threat by macroparasites is responsible for the natural selection of an array of behavioral adaptations that, together with the immune system and other physiological forms of resistance, enable the animals to survive and reproduce in this environment. Several lines of research, some quite recent, illustrate that specific behavioral patterns can be effective in helping animals or their offspring avoid or control macroparasites that can affect adversely the animal's fitness. These behavioral patterns fall under the general strategies of avoidance behavior and mate selection.     

Variation in the Social Systems of Extant Hominoids: Comparative Insight into the Social Behavior of Early Hominins

The observed social systems of extant apes and humans suggest that the common ancestral state for Miocene hominoids was living in multimale–multifemale groups that exhibited a tendency to fission and fusion in response to ecological and/or social variables. The Hominoidea share a set of social commonalities, notably a social niche that extends beyond kin and beyond the immediate social group, as well as extensive intraspecific flexibility in social organization. We propose that an essential feature of hominoid evolution is the shift from limited plasticity in a generalized social ape to expanded behavioral plasticity as an adaptive niche. Whereas in most nonhominoid primates variability and flexibility take the shape of specific patterns of demographic flux and interindividual relationships, we can consider behavioral flexibility and plasticity as a means to an end in hominoid socioecological landscapes. In addition, the potential for innovation, spread, and inheritance of behavioral patterns and social traditions is much higher in the hominoids, especially the great apes, than in other anthropoid primates. We further suggest that this pattern forms a basis for the substantial expansion of social complexity and adaptive behavioral plasticity in the hominins, especially the genus Homo. Our objectives in this article are threefold: 1) summarize the variation in the social systems of extant hominoid taxa; 2) consider the evolutionary processes underlying these variations; and 3) expand upon the traditional socioecological model, especially with respect to reconstructions of early hominin social behavior. We emphasize a central role for both ecological and social niche construction, as well as behavioral plasticity, as basal hominoid characteristics. Over evolutionary time these characteristics influence the patterns of selection pressures and the resulting social structures. We propose that a mosaic of ecological and social inheritance patterns should be considered in the reconstruction of early hominin social systems.     

Comparison of black-footed ferret (Mustela nigripes) and domestic ferret (M. putorius furo) courtship activity

Because of the scarcity of the endangered black-footed ferret (Mustela nigripes) and the amount of knowledge necessary for their conservation, surrogate research can play an important role in recovery. In this paper, we investigate surrogate behavioral research potential by comparing courtship behavior of the black-footed ferret to the congeneric domestic ferret (M. putorius furo). Ten female domestic ferrets were bred to five male domestic ferrets and eight female black-footed ferrets were bred to five black-footed ferret males. Courtship activities were defined, analyzed, and quantitatively compared between both groups. Lag sequential analysis of was used to prepare the behavioral matrices, and matrix cells were compared between groups with an equality of proportions test. Courtship patterns did not differ significantly between the two closely related species, and the domestic ferret would probably be an adequate surrogate for reproductive behavior research on the black-footed ferret.     

时距估计长度效应的研究述评

时距估计的长度效应,是指不同长度的时距存在不同的加工机制。从行为反应、神经心理以及脑成像三个领域对有关长度效应的研究进行综述。行为实验多用双任务范式,考察涉及工作记忆的非时间任务对长短时距加工的影响,行为实验的结果不一致,采用双任务范式的实验证据一般不能证明长度效应的存在。而有关脑机制的神经心理与脑成像研究结果一致,支持存在长度效应,但对于两个计时机制各自涉及的脑区以及脑电活动模式仍没有定论。长短时距可能因为所用任务特征不同采用不同计时机制,今后的研究将重点探讨特定任务是否涉及不同的计时机制。     

A direct test of the effects of changing atmospheric pressure on the mating behavior of Drosophila melanogaster

Changes in weather can be catastrophic for small insects. As such, it would be highly adaptive for insects to be able to sense when a weather front is approaching and respond appropriately. While correlative and anecdotal evidence exists that flies behaviorally respond to changes in barometric pressure, which indicate variation in weather, a direct test has yet to be performed. Here, we subject multiple strains of Drosophila melanogaster to changes in barometric pressure within a hypobaric chamber and measure male courtship and female receptivity. Since this species has a long copulation duration, copulating when adverse weather is approaching could subject both males and females to potentially lethal conditions. As predicted, some flies reduced their mating activity when exposed to a change in pressure that indicated imminent adverse weather. Surprisingly, however, some flies instead increased their mating activity; the behavioral response depended upon the strain’s native population location and intra-population variation, demonstrating that there is genetic variation for the behavioral response. This indicates that flies are able to anticipate weather patterns and change their behavior depending on the barometric pressure they experience, but that the form of behavioral response varies both within and between populations.     

Sexual arousal in men: a review and conceptual analysis

Sexual arousal is an emotional/motivational state that can be triggered by internal and external stimuli and that can be inferred from central (including verbal), peripheral (including genital), and behavioral (including action tendencies and motor preparation) responses. This article, while focusing on sexual arousal in men, provides a conceptual analysis of this construct, reviews models of sexual arousal, and discusses the usefulness of perspectives derived from motivation and emotion research in improving our understanding of its determinants and behavioral correlates. In this, it considers the role of genital feedback in men's subjective sexual arousal and the connections between sexual arousal and sexual desire. Future research and definitions may increasingly focus on its central integrative functions (as opposed to its input and output characteristics). Yet, the study of sexual arousal can be expected to continue to benefit from the measurement of its genital, verbal, and behavioral components. Instances of discordance between response components suggest that they are, at least in part, under the control of different mechanisms, and it is proposed that a better understanding of sexual arousal will prove contingent on a better understanding of such mechanisms and the conditions under which they converge and diverge.     

Coordination dynamics: (in)stability and metastability in the behavioural and neural systems

For more than 20 years, coordination dynamics have provided research on human movement science with new views about the nonlinear relationships between behavioral and neural dynamics. A number of studies across various experimental settings including bimanual, postural or interpersonal coordination, and also coordination between movements of a limb and an external event in the environment revealed the self-organized nature of human coordination. Here we review an extensive body of literature - in the human movement science and the neuroscience fields - that has investigated the coordination dynamics of brain and behavior when individuals are involved in two rhythmic coordination patterns: synchronization (on-the-beat movements) and syncopation (in-between beats movements). When the frequency of movement approaches 2 Hz, the syncopation mode is destabilized and synchronization is spontaneously adopted. The abrupt change between the two patterns illustrates a phenomenon known as non-equilibrium phase transition. Phase transitions offer a novel entry point into the investigation of pattern formation (and dissolution) at both the behavioral and the cerebral levels as they illustrate the loss of stability of the system. Brain imaging methods (MEG, EEG and fMRI) were used to reveal the neural signatures of (in)stability underlying the differences between behavioral coordination patterns, and pointed at the role of self-organization and metastability principles in brain functioning. Relationships between behavioral and brain dynamics can therefore be investigated within a unified empirical and theoretical framework.     

On looking for neural networks and “cell assemblies” that underlie behavior: I. A mathematical model

A list of important features of animal behavior related primarily to learning has suggested to many investigators that an important aspect of brain function is the establishment or modification of functional connections between neural elements. In this paper a considerably, more inclusive list of behavioral features suggests that another important aspect may be the utilization of patterns of activity constituting the resonant responses of linear networks in the brain. To account for the longer list on the basis of connections requires additional assumptions, while both lists follow immediately from the second mechanism. An input locus may become functionally connected to a particular response mode by firing at a frequency which comes to approach the resonant frequency of that mode. The information in a complicated “cell assembly” of the type considered could be transmitted through a nerve tract by a very simple frequency code. One neurological guess is that frequency-coded inputs excite the transients in dedritic networks. It the amplititude of the pattern becomes large, as it would near, resonance, the all-or-none axonal response would become excited. This axonal response would tend to augment resonant patterns and disrupt other patterns, for a reasonal inherent in any linear network. It is shown how the mechanism might be related to the list of important behavioral features, and a numerical illustration is provided. Since this mechanism is automatically present in any linear network, unless special processes suppress it, it must have led to overt hehavior in any animal, possessing such networks. Evolution either suppressed this feature or exploited it. Since its properties resemble those of animal behavior, the latter might be suspected. This research was supported by the Office of Naval Research under Contract No. Nonr 2121(17) NR 049-148. Reproduction in whole or in part is permitted for any purpose of the United States Government.     

Developmental and genetic effects on behavioral and life‐history traits in a field cricket

A fundamental goal of evolutionary ecology is to identify the sources underlying trait variation on which selection can act. Phenotypic variation will be determined by both genetic and environmental factors, and adaptive phenotypic plasticity is expected when organisms can adjust their phenotypes to match environmental cues. Much recent research interest has focused on the relative importance of environmental and genetic factors on the expression of behavioral traits, in particular, and how they compare with morphological and life‐history traits. Little research to date examines the effect of development on the expression of heritable variation in behavioral traits, such as boldness and activity. We tested for genotype, environment, and genotype‐by‐environment differences in body mass, development time, boldness, and activity, using developmental density treatments combined with a quantitative genetic design in the sand field cricket (Gryllus firmus). Similar to results from previous work, animals reared at high densities were generally smaller and took longer to mature, and body mass and development time were moderately heritable. In contrast, neither boldness nor activity responded to density treatments, and they were not heritable. The only trait that showed significant genotype‐by‐environment differences was development time. It is possible that adaptive behavioral plasticity is not evident in this species because of the highly variable social environments it naturally experiences. Our results illustrate the importance of validating the assumption that behavioral phenotype reflects genetic patterns and suggest questions about the role of environmental instability in trait variation and heritability.     

The niche, biogeography and species interactions

In this paper, I review the relevance of the niche to biogeography, and what biogeography may tell us about the niche. The niche is defined as the combination of abiotic and biotic conditions where a species can persist. I argue that most biogeographic patterns are created by niche differences over space, and that even ‘geographic barriers’ must have an ecological basis. However, we know little about specific ecological factors underlying most biogeographic patterns. Some evidence supports the importance of abiotic factors, whereas few examples exist of large-scale patterns created by biotic interactions. I also show how incorporating biogeography may offer new perspectives on resource-related niches and species interactions. Several examples demonstrate that even after a major evolutionary radiation within a region, the region can still be invaded by ecologically similar species from another clade, countering the long-standing idea that communities and regions are generally ‘saturated’ with species. I also describe the somewhat paradoxical situation where competition seems to limit trait evolution in a group, but does not prevent co-occurrence of species with similar values for that trait (called here the ‘competition–divergence–co-occurrence conundrum’). In general, the interface of biogeography and ecology could be a major area for research in both fields.