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A fundamental question of ecology is why species coexist in the same habitat. Coexistence can be enabled through niche differentiation, mediated by trait differentiation. Here, behaviour constitutes an often-overlooked set of traits. However, behaviours such as aggression and exploration drive intra- and interspecific competition, especially so in ants, where community structure is usually shaped by aggressive interactions. We studied behavioural variation in three ant species, which often co-occur in close proximity and occupy similar dominance ranks. We analysed how intra- and allospecific aggression, exploration and foraging activity vary under field conditions, namely with temperature and over time. Behaviours were assessed for 12 colonies per species, and four times each during several months. All behavioural traits consistently differed among colonies, but also varied over time and with temperature. These temperature-dependent and seasonal responses were highly species-specific. For example, foraging activity decreased at high temperatures in Formica rufibarbis, but not in Lasius niger; over time, it declined strongly in L. niger but much less in F. rufibarbis. Our results suggest that, owing to these species-specific responses, no species is always competitively superior. Thus, environmental and temporal variation effects a dynamic dominance hierarchy among the species, facilitating coexistence via the storage effect. [ABSTRACT FROM AUTHOR]

Recent evidence suggests that individuals differ in foraging tactics and this variation is often linked to an individual's behavioural type (BT). Yet, while foraging typically comprises a series of search and handling steps, empirical investigations have rarely considered BT‐dependent effects across multiple stages of the foraging process, particularly in natural settings.In our long‐term sleepy lizard (Tiliqua rugosa) study system, individuals exhibit behavioural consistency in boldness (measured as an individual's willingness to approach a novel food item in the presence of a threat) and aggressiveness (measured as an individual's response to an 'attack' by a conspecific dummy). These BTs are only weakly correlated and have previously been shown to have interactive effects on lizard space use and movement, suggesting that they could also affect lizard foraging performance, particularly in their search behaviour for food.To investigate how lizards' BTs affect their foraging process in the wild, we supplemented food in 123 patches across a 120‐ha study site with three food abundance treatments (high, low and no‐food controls). Patches were replenished twice a week over the species' entire spring activity season and feeding behaviours were quantified with camera traps at these patches. We tracked lizards using GPS to determine their home range (HR) size and repeatedly assayed their aggressiveness and boldness in designated assays.We hypothesised that bolder lizards would be more efficient foragers while aggressive ones would be less attentive to the quality of foraging patches. We found an interactive BT effect on overall foraging performance. Individuals that were both bold and aggressive ate the highest number of food items from the foraging array. Further dissection of the foraging process showed that aggressive lizards in general ate the fewest food items in part because they visited foraging patches less regularly, and because they discriminated less between high and low‐quality patches when revisiting them. Bolder lizards, in contrast, ate more tomatoes because they visited foraging patches more regularly, and ate a higher proportion of the available tomatoes at patches during visits.Our study demonstrates that BTs can interact to affect different search and handling components of the foraging process, leading to within‐population variation in foraging success. Given that individual differences in foraging and movement will influence social and ecological interactions, our results highlight the potential role of BT's in shaping individual fitness strategies and population dynamics. [ABSTRACT FROM AUTHOR]

Abstract The study of consistent between-individual behavioural variation in single (animal personality) and across two or more behavioural traits (behavioural syndrome) is a central topic of behavioural ecology. Besides behavioural type (individual mean behaviour), behavioural predictability (environment-independent within-individual behavioural variation) is now also seen as an important component of individual behavioural strategy. Research focus is still on the ‘Big Five’ traits (activity, exploration, risk-taking, sociability and aggression), but another prime candidate to integrate to the personality framework is behavioural thermoregulation in small-bodied poikilotherms. Here, we found animal personality in thermoregulatory strategy (selected body temperature, voluntary thermal maximum, setpoint range) and ‘classic’ behavioural traits (activity, sheltering, risk-taking) in common lizards (Zootoca vivipara). Individual state did not explain the between-individual variation. There was a positive behavioural type—behavioural predictability correlation in selected body temperature. Besides an activity—risk-taking syndrome, we also found a risk-taking—selected body temperature syndrome. Our results suggest that animal personality and behavioural syndrome are present in common lizards, both including thermoregulatory and ‘classic’ behavioural traits, and selecting high body temperature with high predictability is part of the risk-prone behavioural strategy. We propose that thermoregulatory behaviour should be considered with equal weight to the ‘classic’ traits in animal personality studies of poikilotherms employing active behavioural thermoregulation.

Poison frogs of the superfamily Dendrobatoidea have fascinated researchers since the 19th century, which is reflected in multiple studies on their natural history, taxonomy, toxicity, colour pattern diversity, and elaborate territorial, reproductive and parental care behaviours. Broadly speaking, however, the term "poison frogs" may apply as well to other taxa which also possess skin toxins. Hereon, we refer to poison frogs as this extended group involving, besides Dendrobatoidea (Dendrobatidae + Aromobatidae), a few genera in families such as Bufonidae and Mantellidae (among others). Most studies on poison frogs have focused on species considered charismatic due to their bright and flashy colours, limiting possible generalisations of patterns and mechanisms explaining the high morphological, ecological, and behavioural differentiation, but also convergence, among these groups. Furthering our understanding of the evolutionary ecology of poison frogs requires increasing not only the scope and depth of our own questions, but also the number and diversity of study systems. Inspired by the special issue on dendrobatid and aromobatid poison frogs published ten years ago in this same journal, we have put together the present special issue aiming to broaden both the topics and the coverage of poison frog clades. This first part consists of 15 manuscripts covering topics ranging from larval behavioural ecology and parental care to space use and its environmental determinants, along with conservation implications. [ABSTRACT FROM AUTHOR]

In many species, individual animals often maintain relatively consistent individual differences in behaviour, indicative of temperament or personality. These stable individual differences are important for life history, survival and health consequences, and the field has seen exponential growth in temperament (e.g. boldness, exploration, sociability, aggression and activity) research. Quantification of animal temperament can be difficult because it requires (1) repeated behavioural measures from the same individual (to gauge within-individual consistency across time and contexts) and (2) identification of the most appropriate behaviour(s) to characterize temperament. In the current study, we took an atheoretical approach and conducted repeat, diverse behavioural tests in a low-variable environment to determine behaviours that were individually consistent over time and across conditions. To control environmental effects on behaviour, we conducted this work with individually housed outbred male Sprague–Dawley rats in a laboratory. To determine individual consistency, we measured each rat's behavioural response to five different arenas (i.e. different contexts) and repeated the five tests at three time points. To identify potential composite, multibehaviour estimates of temperament, we used factor analyses to determine behaviours that covaried on each test arena, and calculated factor scores. To determine individual consistency of behaviours and factor scores across time and contexts, we used reliability and correlation analyses. Several behaviours consistently covaried on each test, and with a few notable exceptions, the resulting factors tended to align with five commonly studied temperament categories. Certain behaviours/factors were more consistent across time and contexts than others; distance travelled/activity were highly consistent, as were sociality- and boldness-related behaviours, whereas aggression and exploration were less consistent. We did not find strong evidence that multibehaviour estimates of temperament (factor scores) were more consistent over time or across conditions than single-behaviour metrics. Where possible, similar atheoretical approaches to cross-time and cross-context behaviour testing will be beneficial for initial temperament characterization. • We quantified behavioural traits in male laboratory rats in low-variable conditions. • Male behaviour was tested on five different arenas, each repeated three times. • Multibehaviour factors scores were no more consistent than single behaviours. • Activity and social boldness were consistent across time and across contexts. [ABSTRACT FROM AUTHOR]

Foraging specialization, whereby animals exploit only a minor fraction of the population's foraging home range or trophic niche, may arise as a response to increasing levels of intraspecific competition. This phenomenon may be particularly frequent in colonial species, when individuals breed in large aggregations and are constrained to exploit shared foraging areas surrounding the colony site where competition for access to food resources may be high. Foraging specialization may be driven by individual foraging site fidelity, occurring whenever individuals consistently target specific foraging sites, which may differ from those used by other colony members. We assessed the extent of foraging specialization in a colonial breeding raptor, the lesser kestrel, Falco naumanni , by estimating the repeatability of foraging movement patterns of 45 GPS-tracked individuals during both incubation and nestling rearing. We found that the consistency of individual movement patterns was generally higher during nestling rearing than during incubation. Nestling-rearing individuals, but not incubating ones, travelled along relatively consistent routes when targeting foraging grounds and tended to target the same foraging areas throughout the tracking period. In colonial birds, and likely in altricial species more generally, an increased individual foraging site fidelity during nestling rearing versus incubation may result from increased energy demands due to frequent nestling provisioning in addition to self-provisioning. By consistently exploiting previously visited foraging sites that are likely to be rewarding, nestling-rearing birds might indeed increase their foraging efficiency, shortening food-searching time and maximizing their foraging effort. In addition, the use of distinct foraging areas may reduce intraspecific competition for food, thus buffering an important cost of coloniality. • Nestling-rearing lesser kestrels showed high individual foraging site fidelity. • Incubating birds were less consistent in foraging movement and commuting routes. • Site fidelity likely resulted in optimized foraging effort and food-searching time. • Site fidelity may increase foraging efficiency in a high energy-demanding phase. • Using distinct foraging sites could also reduce intraspecific competition. [ABSTRACT FROM AUTHOR]

Interactions in social groups can promote behavioural specialization. One way this can happen is when individuals engage in activities with two behavioural options and learn which option to choose. We analyse interactions in groups where individuals learn from playing games with two actions and negatively frequency-dependent payoffs, such as producer–scrounger, caller–satellite, or hawk–dove games. Group members are placed in social networks, characterized by the group size and the number of neighbours to interact with, ranging from just a few neighbours to interactions between all group members. The networks we analyse include ring lattices and the much-studied small-world networks. By implementing two basic reinforcement-learning approaches, action–value learning and actor–critic learning, in different games, we find that individuals often show behavioural specialization. Specialization develops more rapidly when there are few neighbours in a network and when learning rates are high. There can be learned specialization also with many neighbours, but we show that, for action–value learning, behavioural consistency over time is higher with a smaller number of neighbours. We conclude that frequency-dependent competition for resources is a main driver of specialization. We discuss our theoretical results in relation to experimental and field observations of behavioural specialization in social situations. [ABSTRACT FROM AUTHOR]

Using situation-specific and dyadic data, we analyse how trust in inter-organisational relationships evolve over time. Based on a multidisciplinary approach, we define four trust-related concepts, which include both behavioural and perceptual aspects of this multifaceted phenomenon. We also develop the hypothesis that the behavioural consistency of the trustee affects the level of his/her trustworthiness as perceived by the trustor. To test this hypothesis, the paper specifies a finite Dynamic Trust Game that, in a unique way, models longer-term relationships characterised by interdependent actions between partners. In contrast to the simple Repeated Games modelling discrete exchange episodes, this game corresponds to the requirements of the interaction approach of the relationship management, since the iterations of the game are interrelated and embedded in previous ones. Timely development of the behavioural variables in the game reflects an inverse U-shape with an increasing willingness to cooperate until round 8, with a maximum cooperation level of 80% on average. Behaviour seems to affect the perceived level of trustworthiness. However, we need additional experimental data on inconsistent behaviours to get a clear understanding of this effect. [ABSTRACT FROM AUTHOR]

Behavioural variation in courtship has become a central theme in the study of sexual selection. Courtship behaviour can vary consistently between males (between-individual variation) due to inherent characteristics of individuals, but males may also plastically adjust their courtship (within-individual variation) in response to the characteristics of the potential breeding mate or the environmental contexts. However, the relative importance of these components in courtship behaviour remains poorly understood. Here, we exposed male collared flycatchers, Ficedula albicollis , to different stimulus females simulating a female's visit to the male's territory during mate choice. We measured the male's latency to explicitly invite the female to visit the nestbox (hereafter, invitation latency), as a proxy of the male's motivation to mate. Repeated measurements of focal males (exposed to different stimulus females) and stimulus females (presented to different males) allowed us to assess the relative importance of male and female identity in male courtship, while also assessing the importance of their phenotype and other environmental sources of within-individual variation in invitation latency. We found that invitation latency was determined by male and, to a lesser extent, female identity, with the latter suggesting the existence of male mate choice in the species. We failed to identify specific traits of males and females that influenced courtship behaviour, although male responsiveness to stimulus females increased as the season advanced, possibly due to the costs of delaying breeding in temperate breeding areas. Overall, these results suggest that invitation latency is a consistent courtship attribute in males that can be adjusted plastically according to perceived female quality and environmental conditions. We emphasize that understanding within- and between-individual sources of courtship variation is essential for assessing its evolutionary potential, as plasticity in the expression of sexual signals may affect their reliability and the strength of sexual selection on them. • We simulated female visits to the male's territory and measured courtship. • Courtship behaviour varied consistently between males. • Males adjusted their courtship according to perceived female identity. • Courtship behaviour was also sensitive to seasonality. • Plasticity in sexual signal expression may affect the strength of sexual selection. [ABSTRACT FROM AUTHOR]

Whether animal personality studies provide insights of broader evolutionary and ecological relevance to the field of behavioural ecology is frequently questioned. One of the sources of controversy is the vast, but often vague terminology present in the field. From a statistical perspective, animal personality is defined as among-individual variance in behaviour. However, numerous conceptual definitions of animal personality are available in the literature. Here, we performed (i) a self-report questionnaire and (ii) a systematic literature review to quantify how researchers interpreted conceptual and statistical definitions commonly used in animal personality research. We also compared whether data obtained from the questionnaire matched with data from the literature review. Among the 430 self-reported researchers that participated in our questionnaire, we observed discrepancies in key questions such as the conceptual definition of animal personality or the interpretation of repeatability. Furthermore, our literature review generally confirmed the global patterns revealed by the questionnaire. Overall, we identified common disagreements within the field of animal personality and discussed potential solutions. We advocate for adopting a terminology that avoids ambiguous interpretations and helps to make more explicit the widespread connotations implicit in the label ‘animal personality’. [ABSTRACT FROM AUTHOR]

Animal behaviour research has experienced a renewed interest in consistent individual differences (i.e. animal personality or temperament). Recent ecological studies have identified environmental conditions that give rise to the development and evolution of temperaments and to fitness-related outcomes of temperament. Additional literature has also described relationships between temperaments and physiological regulation. However, one-to-one relationships between one behavioural trait and one physiological system do not account for co-selection of behavioural and physiological traits, nor the complex signalling among physiological systems. In the current paper, we review the literature on multiple physiological processes associated with temperament, propose temperament-specific physiological profiles, and focus on next steps to understand the functional significance, evolution and maintenance of temperaments. We propose that to understand causes and consequences of temperament we need to characterize integrative physiological profiles associated with different temperaments. [ABSTRACT FROM AUTHOR]

1. Individual specialisations in behaviour are predicted to arise where divergence benefits fitness. Such specialisations are more likely in heterogeneous environments where there is both greater ecological opportunity and competition-driven frequency dependent selection. 2. Such an effect could explain observed differences in rates of individual specialisation in habitat selection, as it offers individuals an opportunity to select for habitat types that maximise resource gain while minimising competition; however, this mechanism has not been tested before. 3. Here, we use habitat selection functions to quantify individual specialisations while foraging by black-legged kittiwakes Rissa tridactyla, a marine top predator, at 15 colonies around the United Kingdom and Ireland, along a gradient of environmental heterogeneity. 4. We find support for the hypothesis that individual specialisations in habitat selection while foraging are more prevalent in heterogeneous environments. This trend was significant across multiple dynamic habitat variables that change over short time-scales and did not arise through site fidelity, which highlights the importance of environmental processes in facilitating behavioural adaptation by predators. 5. Individual differences may drive evolutionary processes, and therefore these results suggest that there is broad scope for the degree of environmental heterogeneity to determine current and future population, species and community dynamics. [ABSTRACT FROM AUTHOR]

Urban animals often show bolder behaviour towards humans than their nonurban conspecifics. However, it is unclear to what extent this difference is due to consistent individual characteristics or to plasticity such as habituation. To address this question, we investigated parental risk-taking behaviour in 371 female great tits in urban and forest populations by checking their nest repeatedly (several times per week, for up to nine breeding episodes) and recording their behavioural responses to this recurring disturbance during incubation. We found that urban females were bolder, as they stayed on the nest more often than females in forests. Furthermore, great tits produced alarm calls around the nests more frequently in urban than in forest habitats. There was no habitat difference in the frequency of an antipredator behaviour, the hissing threat display on the nest, although this was rare in both habitats. We also tested the consistency and plasticity of risk-taking behaviour on three different temporal scales (within breeding attempts, between broods within a year and across years). Staying on the nest was highly repeatable within females, whereas alarm calls had low repeatability within pairs at all three temporal scales. The probability of staying on the nest increased within breeding attempts, whereas the probability of alarm calls increased across years. Neither consistency nor plasticity in these components of risk taking differed between urban and forest habitats. We conclude that urban birds are bolder in multiple behavioural measures and, overall, both stable individual differences and behavioural plasticity may have contributed to the higher risk taking we often see in urban populations. Furthermore, staying on the nest appears to be an individually consistent trait in female great tits regardless of habitat urbanization, providing a low-impact measurement of risk taking, which may potentially facilitate field studies related to individual differences in behaviour. • Urban great tits alarm-call at humans more than their forest conspecifics. • Urban females stay on the nest upon human disturbance more often than forest birds. • Staying on the nest is repeatable, increases during incubation but not across years. • Neither repeatability nor plasticity of risk taking differs between cities and forests. • Staying on the nest might be a good proxy of boldness in female birds. [ABSTRACT FROM AUTHOR]

Limited flexibility in behaviour gives rise to behavioural consistency, so that past behaviour is partially predictive of current behaviour. The consequences of limits to flexibility are investigated in a population in which pairs of individuals play a game of trust. The game can either be observed by others or not. Reputation is based on trustworthiness when observed and acts as a signal of behaviour in future interactions with others. Individuals use the reputation of partner in deciding whether to trust them, both when observed by others and when not observed. We explore the effects of costs of exhibiting a difference in behaviour between when observed and when not observed (i.e. a cost of flexibility). When costs are low, individuals do not attempt to signal that they will later be trustworthy: their signal should not be believed since it will always pay them to be untrustworthy if trusted. When costs are high, their local optimal behaviour automatically acts as an honest signal. At intermediate costs, individuals are very trustworthy when observed in order to convince others of their trustworthiness when unobserved. It is hypothesized that this type of strong signalling might occur in other settings. [ABSTRACT FROM AUTHOR]

Foraging is a behaviour that can be influenced by multiple factors and is highly plastic. Recent studies have shown consistency in individual foraging behaviour has serious ecological and evolutionary implications within species and populations. Such information is crucial to understand how species select habitats, and how such selection might allow them to adapt to the environmental changes they face. Five foraging metrics (maximum distance from the colony, bearing from the colony to the most distal point, tortuosity index, total number of dives and mean vectorial dynamic body acceleration were obtained using GPS tracking and accelerometry data in adult Australasian gannets (Morus serrator) from two colonies in southeastern Australia. Individuals were instrumented over two breeding seasons to obtain data to assess factors influencing foraging behaviour and behavioural consistency over multiple timescales (consecutive trips, breeding stages and years) and habitats (pelagic, mixed pelagic and inshore, and inshore). Colony, breeding stage and year were the factors which had the greatest influence on foraging behaviour, followed by sex. Behavioural consistency, measured as the contribution of the individual to the observed variance, was low to moderate for all foraging metrics (0.0–27.05%), with the higher values occurring over shorter timescales. In addition, behavioural consistency was driven by spatio-temporal factors rather than intrinsic characteristics. Behavioural consistency was higher in individuals foraging in inshore than pelagic habitats or mixed pelagic/inshore strategy, supporting suggestions that consistency is favoured in stable environments.

Many populations consist of individuals that differ consistently in their foraging behaviour through resource or foraging site selection. Foraging site fidelity has been reported in several seabird species as a common phenomenon. It is considered especially beneficial in spatially and/or temporally predictable environments in which fidelity is thought to increase energy intake, thereby affecting time‐energy budgets. However, the consequences for activity and energy budget have not been adequately tested. In this paper, we studied the consequences of fine‐scale foraging site fidelity in adult Herring Gulls Larus argentatus in a highly predictable foraging environment with distinct foraging patches. We measured their time‐activity budgets using GPS tracking and tri‐axial acceleration measurements, which also made it possible to estimate energy expenditure. Individual variation in foraging site fidelity was high, some individuals spending most of their time on a single foraging patch and others spending the same amount of time in up to 21 patches. While time and activity budgets differed between individuals, we found no clear relationship with foraging site fidelity. We did find a relationship between the size of the birds and the level of site fidelity; faithful birds tend to have a larger body size. Although differences in foraging time and habitat use between individuals could play a role in the results of the current study, short‐term consequences of variation in foraging site fidelity within a population remain elusive, even when focusing on individuals with a similar foraging specialization (Blue Mussels Mytilus edulis). Studying individuals over multiple years and under varying environmental conditions may provide better insight into the consequences and plasticity of foraging site fidelity. [ABSTRACT FROM AUTHOR]

Crime linkage has been the subject of increasing attention in academic research. Research has found support for the principles of behavioural consistency and distinctiveness, which underpin crime linkage, but this does not provide direct evidence as to whether crime linkage is useful in practice. This literature review draws together documentation that refers to the practice of crime linkage, from assessing analysts' efficacy, to discussing the usage of computerised tools to assist with the linkage process, to providing a comprehensive outline of the process itself. The implications of the amount and type of information currently available are discussed, including the variations in practice and terminology that were explored. Avenues for future investigation and the manner in which future research could be conducted are set out in a research agenda. [ABSTRACT FROM AUTHOR]

Abstract Background Accelerometers are powerful sensors in many bio-logging devices, and are increasingly allowing researchers to investigate the performance, behaviour, energy expenditure and even state, of free-living animals. Another sensor commonly used in animal-attached loggers is the magnetometer, which has been primarily used in dead-reckoning or inertial measurement tags, but little outside that. We examine the potential of magnetometers for helping elucidate the behaviour of animals in a manner analogous to, but very different from, accelerometers. The particular responses of magnetometers to movement means that there are instances when they can resolve behaviours that are not easily perceived using accelerometers. Methods We calibrated the tri-axial magnetometer to rotations in each axis of movement and constructed 3-dimensional plots to inspect these stylised movements. Using the tri-axial data of Daily Diary tags, attached to individuals of number of animal species as they perform different behaviours, we used these 3-d plots to develop a framework with which tri-axial magnetometry data can be examined and introduce metrics that should help quantify movement and behaviour. Results Tri-axial magnetometry data reveal patterns in movement at various scales of rotation that are not always evident in acceleration data. Some of these patterns may be obscure until visualised in 3D space as tri-axial spherical plots (m-spheres). A tag-fitted animal that rotates in heading while adopting a constant body attitude produces a ring of data around the pole of the m-sphere that we define as its Normal Operational Plane (NOP). Data that do not lie on this ring are created by postural rotations of the animal as it pitches and/or rolls. Consequently, stereotyped behaviours appear as specific trajectories on the sphere (m-prints), reflecting conserved sequences of postural changes (and/or angular velocities), which result from the precise relationship between body attitude and heading. This novel approach shows promise for helping researchers to identify and quantify behaviours in terms of animal body posture, including heading. Conclusion Magnetometer-based techniques and metrics can enhance our capacity to identify and examine animal behaviour, either as a technique used alone, or one that is complementary to tri-axial accelerometry.

Research on brood parasitism has focused primarily on specific host anti-parasite behaviours and parasite counter-adaptations, and little is known about other aspects of their behaviours such as consistent behavioural differences between individuals. Therefore, we examined consistency in behaviour of nestlings of common cuckoos (Cuculus canorus) raised by great reed warblers (Acrocephalus arundinaceus). Cuckoo chicks showed high repeatability of both aggressive behaviour and breath rate, and both traits were strongly correlated with each other. This represents the first evidence for consistent differences in behaviour among avian brood parasites. Males were consistently more aggressive and less stressed than females. Nestlings of both sexes that hatched later in the season exhibited higher levels of aggression and lower stress responses than nestlings hatched earlier. This suggests that rearing conditions (e.g., food availability and quality) may modulate stress and aggressive phenotypes of brood parasites. We discuss potential effects of the observed patterns on host-parasite dynamics. [ABSTRACT FROM AUTHOR]

Studies of animal personality have shown consistent between-individual variation in behaviour in many social and non-social contexts, but hunting behaviour has been overlooked. Prey capture sequences, especially in invertebrates, are supposed to be quite invariant. In cuttlefish, the attack includes three components: attention, positioning, and seizure. The previous studies indicated some variability in these components and we quantified it under the hypothesis that it could relate to personality differences. We, therefore, analysed predation sequences of adult cuttlefish to test their association with personality traits in different contexts. Nineteen subjects were first exposed to an “alert” and a “threat” test and then given a live prey, for 10 days. Predation sequences were scored for components of the attack, locomotor and postural elements, body patterns, and number of successful tentacle ejections (i.e. seizure). PCA analysis of predatory patterns identified three dimensions accounting for 53.1%, 15.9%, and 9.6% of the variance and discriminating individuals based on “speed in catching prey”, “duration of attack behaviour”, and “attention to prey”. Predation rate, success rate, and hunting time were significantly correlated with the first, second, and third PCA factors, respectively. Significant correlations between capture patterns and responsiveness in the alert and threat tests were found, highlighting a consistency of prey capture patterns with measures of personality in other contexts. Personality may permeate even those behaviour patterns that appear relatively invariant. [ABSTRACT FROM AUTHOR]

Background In many species, males have a lower reproductive investment than females and are therefore assumed to increase their fitness with a high number of matings rather than by being choosy. However, in bi-parental species, also males heavily invest into reproduction. Here, reproductive success largely depends on costly parental care; with style and amount of parental effort in several cases being associated with personality differences (i.e., consistent between-individual differences in behaviour). Nonetheless, very little is known about the effect of personality differences on (male) mate choice in bi-parental species. Methods In the present study, we tested male mate choice for the level and consistency of female boldness in the rainbow krib, Pelviachromis pulcher, a bi-parental and territorial West African cichlid. Individual boldness was assumed to indicate parental quality because it affects parental defence behaviour. For all males and females, boldness was assessed twice as the activity under simulated predation risk. Mate choice trials were conducted in two steps. First, we let a male observe two females expressing their boldness. Then, the male could choose between these two females in a standard mate choice test. Results We tested for a male preference for behavioural (dis-)similarity vs. a directional preference for boldness but our data support the absence of effects of male and/or female boldness (level and consistency) on male mating preference. Discussion Our results suggest female personality differences in boldness may not be selected for via male mate choice.

Data on personality for long-lived, highly social wild mammals with high cognitive abilities are rare. We investigated the personality structure of Asian elephants (Elephas maximus) by using a large sample of semi-captive timber elephants in Myanmar. Data were collected during 2014–2017 using questionnaires, for which elephant riders (mahouts) rated 28 behavioural adjectives of elephants. Repeated questionnaires were obtained for each elephant from several raters whenever possible, resulting in 690 ratings of 150 female and 107 male elephants. We started by performing a confirmatory factor analysis to compare the fit of our data to a previously published captive elephant personality structure. Owing to a poor fit of this model to our data, we proceeded by performing explanatory factor analysis to determine the personality structure in our study population. This model suggested that personality in these elephants was manifested as three factors that we labelled as Attentiveness, Sociability and Aggressiveness. This structure did not differ between the sexes. These results provide the basis for future research on the link between personality and reproductive success in this endangered species and more generally, help to resolve the selective pressures on personalities in long-lived, highly social species.

Background. In many species, males have a lower reproductive investment than females and are therefore assumed to increase their fitness with a high number of matings rather than by being choosy. However, in bi-parental species, also males heavily invest into reproduction. Here, reproductive success largely depends on costly parental care; with style and amount of parental effort in several cases being associated with personality differences (i.e., consistent between-individual differences in behaviour). Nonetheless, very little is known about the effect of personality differences on (male) mate choice in bi-parental species. Methods. In the present study, we tested male mate choice for the level and consistency of female boldness in the rainbow krib, Pelviachromis pulcher, a bi-parental and territorial West African cichlid. Individual boldness was assumed to indicate parental quality because it affects parental defence behaviour. For all males and females, boldness was assessed twice as the activity under simulated predation risk. Mate choice trials were conducted in two steps. First, we let a male observe two females expressing their boldness. Then, the male could choose between these two females in a standard mate choice test. Results. We tested for a male preference for behavioural (dis-)similarity vs. a directional preference for boldness but our data support the absence of effects of male and/or female boldness (level and consistency) on male mating preference. Discussion. Our results suggest female personality differences in boldness may not be selected for via male mate choice. [ABSTRACT FROM AUTHOR]

Abstract: Spatio‐temporally stable prey distributions coupled with individual foraging site fidelity are predicted to favour individual resource specialisation. Conversely, predators coping with dynamic prey distributions should diversify their individual diet and/or shift foraging areas to increase net intake. We studied individual specialisation in Scopoli's shearwaters (Calonectris diomedea) from the highly dynamic Western Mediterranean, using daily prey distributions together with resource selection, site fidelity and trophic‐level analyses. As hypothesised, we found dietary diversification, low foraging site fidelity and almost no individual specialisation in resource selection. Crucially, shearwaters switched daily foraging tactics, selecting areas with contrasting prey of varying trophic levels. Overall, information use and plastic resource selection of individuals with reduced short‐term foraging site fidelity allow predators to overcome prey field lability. Our study is an essential step towards a better understanding of individual responses to enhanced environmental stochasticity driven by global changes, and of pathways favouring population persistence. [ABSTRACT FROM AUTHOR]

Whilst investigative use of behavioural evidence to help link and solve serial offences has long been in use, the empirical and theoretical grounds for whether and how to use this evidence effectively have begun to emerge only in recent decades. The present study empirically tested (a) the potential for effectively differentiating between rape offence crime scenes using quantitative and qualitative distinctions within the behavioural dimensions of control, violence, and sexual activity, and (b) the extent to which redefining behavioural consistency more broadly to include dynamic trajectories of behavioural change may be more effective than limiting this definition to behavioural stability. Results confirmed that sexual offences can be successfully differentiated based on the specific degree and subtype of these behavioural dimensions present in each crime scene. The analysis of consistency and behavioural trajectories showed that whilst none of the offenders exhibited complete consistency across behavioural dimensions, a subsample of offenders remained fully consistent in at least one. Furthermore, of those who were not consistent, the vast majority followed an identifiable trajectory of change. Findings are discussed in the context of psychological theories of behavioural consistency as well as practical aspects of advancing the utility of behavioural linkage. [ABSTRACT FROM AUTHOR]

Work on the repeatability of reproductive behaviour has mainly focused on the consistency of female preferences. We characterised the consistency of individual male Drosophila melanogaster reproductive behaviour in two experiments. In the first experiment, we allowed males to interact with a pair of live females that differed in body size. We then controlled female behaviour in a second experiment by examining the courtship behaviour of individual males interacting with a pair of decapitated females that varied in body size. In both experiments, we examined the consistency of individual male reproductive behaviour across two repeated trials on the same day. Males did not exhibit a courtship preference for the larger female in either experiment, but, in experiment 1, males did exhibit post-copulatory choice by copulating for longer durations with the large female, and males that mated with the same type of female in both trials exhibited repeatable behaviour. In general, we found weak evidence of consistent male courtship behaviour in the presence of behaving females. However, when female behaviour was controlled in experiment 2, we found that male courtship behaviour was highly repeatable. These results indicate that individual male D. melanogaster exhibit consistent reproductive behaviour and demonstrate the importance of controlling female behaviour when attempting to characterise the repeatability of male reproductive behaviour. [ABSTRACT FROM AUTHOR]

Consistent and correlated inter-individual differences in behaviours, the so-called 'personalities', have been identified in many vertebrates. The ability to respond to stressful events is part of personalities and can have important fitness consequences, as it determines how individuals cope with environmental challenges. As a consequence of pleiotropic effects of genes involved in several functions, inter-individual differences in behavioural responses can be associated with phenotypic traits, like melanin-based plumage colouration in birds. We examined the association between three proxies of the behavioural stress response and breast plumage colouration in barn swallow (Hirundo rustica) nestlings. We found that nestling behavioural responses were consistent within individuals and similar among siblings, thus suggesting that these behaviours may contribute to define individual 'personalities'. However, nestling behavioural stress response was not significantly predicted by variation in breast plumage colouration, indicating that in juveniles of this species melanin-based colouration does not convey to conspecifics reliable information on individual ability to cope with stressful events. [ABSTRACT FROM AUTHOR]

Free-range systems provide an outdoor range for broilers to give them the possibility to express a higher frequency and a wider range of behaviours, such as exploration, compared with those raised indoors. Greater variability in outdoor range use between individuals of the same flock is often reported. Individual variation in range use may result from differences in early-life behaviour or genetic background. Understanding how early-life behaviour influences range use may provide opportunities to enhance and predict range use. Previous studies have shown that range use could be influenced by the animal's personality traits such as social motivation, boldness and foraging motivation. Therefore, this study investigated personality traits in several broiler strains, namely Hubbard JA757, Hubbard S757N, White Bresse and a dual-purpose strain; we examined the latter as it represents a potential solution to the ban of 1-day-old chick culling. The present study also investigated early-life behaviours, before range access, of range use to identify and assess the stability of these early-life indicators among the four broiler strains. For that purpose, we recorded the behaviour and range use of 100 male chickens per strain, both in the barn and during individual tests, before and after range access. We examined which behaviours were time consistent, whether early-life behaviours were influenced by genetic variation and whether early-life behavioural indicators predicted range use regardless of genetic variation. There was a significant (p < 0.001) difference between strains in several early-life behaviours, including the time spent resting or standing. Range use was time consistent regardless of the strain as our range use indicator followed a high-quality linear regression model (R² > 0.7) for 82–99% of the individuals depending on their strain. Besides, time consistency of social motivation and boldness seemed to depend on the strain. Even though foraging showed low (rho = 0.2–0.4) positive correlations with range use in three of the four studied strains, there were no significant and strong correlations in the four studied strains between early-life behavioural indicators and range use. In conclusion, our results show that the link between chick behaviour (before range access) and range use can be modulated by the bird's strain. It is crucial to consider all these different factors to better understand how range use varies within and between flocks. [Display omitted] • Chicken early-life behaviours depend on the genetic strain. • Range use seems to be a stable personality trait in chickens regardless of the strain. • Sociability and boldness may be personality traits in chickens depending on genetics. • No early-life behaviour (locomotion, resting, etc.) predicted range use in all strains. • Foraging behaviour before range access calls for further investigation. [ABSTRACT FROM AUTHOR]

The individual animal is currently a major focus of behavioural research and an increasing number of studies raise the question of how between-individual behavioural consistency and behavioural plasticity interact. Applying the reaction norm concept on groups, our study addresses both of these aspects in one framework and within an animal's natural social environment. Risk-taking behaviour in 1-year-old perch Perca fluviatilis was assayed in aquarium experiments before and after the fish were subjected to the presence or absence of a piscivorous predator for 3 weeks. To analyse the inter-individual behavioural variation across the repeated measurements, we dissected the behavioural change across the predator treatment into individual constant and plastic components using hierarchical mixed-effects models. During the predator treatment, juvenile perch increased in boldness and decreased in vigilance, the magnitude of these behavioural changes was influenced by group composition. However, the behavioural changes were not influenced by the presence of a predator, indicating the difficulties in generating realistic long-term predation pressure in the laboratory. Individuals differed in the relative increase in boldness across the predator treatment and, thus, varied in the shape of their reaction norms. In accordance, the best linear unbiased predictors, extracted from the random effects of separate linear mixed-effects models for the data before and after the predator treatment were only weakly correlated. Hence, between-individual variation seems to change under laboratory conditions and therewith not necessarily represents the initially present 'natural' variation, giving important implications for the conduction and interpretation of behavioural experiments. [ABSTRACT FROM AUTHOR]

Individuals select from a number of behaviours when responding to various situations and the decisions they make may affect their fitness. The costs and benefits of these responses vary among individuals causing them to differ even in identical situations. One example of this type of situation is when territorial males encounter both a male and female simultaneously, gene- rating a trade-off that likely leads to individual differences due to differing costs of various actions among males. This situation commonly occurs in threespine stickleback, Gasterosteus aculeatus. However, for selection to act effectively, individuals must behave in a consistent manner and measuring repeatability can aid in understanding how selection may shape such trade-offs. Males of this species exhibit consistent individual differences in their response to dummy males and females but it is unknown if patterns are similar when feedback from the stimuli is present. To assess this, male threespine stickleback were tested with dummy and live male and female conspecifics, presented separately and simultaneously. While the same trends were found regardless of stimulus type, males were more aggressive towards the live conspecifics than to the dummies. Repeatability values were similar within a treatment regardless of whether live or dummy conspecifics were used, suggesting that individuals show the same level of consistency. This study adds to our understanding of consistent individual differences by demonstrating that feedback may not affect responses to conflicting stimuli and that male threespine stickleback respond in a consistent manner to both dummy and live stimuli [Current Zoology 57 (1): 101–108, 2011].

Individuals within populations can use different resources, leading to ecological segregation and niche variation. This segregation could have direct impacts on the migratory strategy or breeding success, thus affecting the overall population and community dynamics and, ultimately, survival. In this study, we assessed the inter-annual and within individual foraging ecology of an endemic and highly threatened seabird species, the Desertas petrel P terodroma deserta, during the breeding and non-breeding phases. We combined 54 annual tracks (26 individuals; 2009-2013) obtained with light-level loggers (Global Location Sensing or GLS loggers) with stable isotope analyses (δ15N and δ13C) of blood (plasma and cells) and feathers. Wide-ranging tracking data show that this species is a generalist predator, able to adapt to very different habitats. All birds remained faithful to their selected non-breeding areas over the years leading to very high spatial, temporal and trophic consistency among years (i.e. usually with intra-correlation coefficient values, which is an index of repeatability of > 40%). During both the breeding and non-breeding seasons, individual birds showed narrow and segregated isotopic niches, indicating a high level of specialization and limited choice of prey and habitats. The conservation of a seabird with such a dispersive (species-level) yet consistent (individual-level) non-breeding distribution pattern represents a challenge in marine policy terms. On the one hand, such a consistent temporal and spatial pattern will help with defining core areas for conservation, which could be protected through specific management measures or by the establishment of marine protected areas. Yet, their relatively large size (on average 4000 km2) and extent over both national and international waters, where different legislative frameworks apply, will require the coordinated action by many nations, international organizations and multilateral environmental agreements. [ABSTRACT FROM AUTHOR]

The last decade has seen lots of studies on 'animal personality' (i.e. the study of consistent between-individual behavioural differences). As timely and promising as this field is, its development has come with a diversity of research questions. As an unfortunate consequence, it now suffers from substantial confusion about what 'animal personality' is, and how relevant related research frameworks are. Here, we stress the current inconsistencies and sources of confusion pertaining to the field, and their consequences on terminology used and miscommunication between researchers. In an attempt to unravel and clarify the concepts underlying the field, we identify two distinct, but complementary, theory-driven conceptual frameworks: the intra-individual variability ( IIV) approach and the life-history ( LH) approach, which we believe encompass the vast majority of existing 'personality studies'. Finally, we argue in favour of theory-driven studies of consistent behavioural differences and state that the integrative statistical properties of random regression models should not override the merit of alternative conceptual frameworks. We then provide brief guidelines and warnings for a parsimonious and sound use of terminology. [ABSTRACT FROM AUTHOR]

Across a range of species including humans, personality traits, or differences in behaviour between individuals that are consistent over time, have been demonstrated. However, few studies have measured whether these consistent differences are evident in very young animals, and whether they persist over an individual’s entire lifespan. Here we investigated the begging behaviour of very young cross-fostered zebra finch nestlings and the relationship between that and adult activity levels. We found a link between the nestling activity behaviour head movements during begging, measured at just five and seven days after hatching, and adult activity levels, measured when individuals were between three and three and a half years old. Moreover, body mass was found to be negatively correlated with both nestling and adult activity levels, suggesting that individuals which carry less body fat as adults are less active both as adults and during begging as nestlings. Our work suggests that the personality traits identified here in both very young nestlings and adults may be linked to physiological factors such as metabolism or environmental sources of variation. Moreover, our work suggests it may be possible to predict an individual’s future adult personality at a very young age, opening up new avenues for future work to explore the relationship between personality and a number of aspects of individual life history and survival.

The present study investigated behavioural consistency across sexual offending. Variations in behavioural consistency may arise from an increased influence of situational and contextual aspects. However, there is paucity of research exploring variations in behavioural consistency relative to the temporal sequence of the behaviour (e.g., occurring prior to or during the offence). A sample of 49 male serial stranger sexual offenders responsible for 147 offences across four temporal phases of a sexual offence was used in the current study. For each offence, four crime phases were identified: 1) pre-crime, 2) victim selection, 3) approach, and 4) assault. Behavioural consistency within and across offence series were examined utilizing Jaccard's Coefficient and Receiver Operating Characteristics (ROC). Results indicated a high degree of behavioural consistency across all crime aspects; behaviours that were more dependent on situational influences were inherently less predictable and demonstrated to be less consistent. Further, increased behavioural consistency was associated with offender characteristics of a more stable nature. The implications of these findings are discussed. [ABSTRACT FROM AUTHOR]

Criminal profiling is used in complex investigations, and, in a number of jurisdictions, as expert evidence in criminal trials. This article seeks to move beyond the many anecdotal accounts of success by profilers and examine the evidence available as to the discipline's validity. As it stands, profiling is based on theories that are uncertain at best, and little research has been undertaken to assess the actual accuracy of generated profiles. This absence of validation is in part due to genuine difficulties associated with designing appropriate testing models. It is exacerbated by the reluctance of profilers to engage in such a process, relying instead on the well-rehearsed, yet somewhat circular argument that the continuing demand for profiling advice is in itself reassuring evidence of the method's validity. It is the lack of objective evidence of validity in this area that will be critically considered in this article. [ABSTRACT FROM PUBLISHER]