Consistent Individual Differences Research Articles

Individual variation in breeding phenology and postnatal development in northern bats (Eptesicus nilssonii).

Bats inhabiting northern latitudes are faced with short reproductive seasons during which they must produce and rear pups before fattening up in time to survive the winter hibernation. Therefore, the timing of parturition has considerable impacts on future fitness prospects for the mother and pup. However, little is known about individual variation in breeding phenology and its consequences for postnatal development within bat populations. Here, we studied the phenology of breeding in Eptesicus nilssonii across 7 years using data collected by day-to-day monitoring of a breeding colony in Norway (60.1° N) for which the identity and age of each mother (N = 8) and pup (N = 28) were known. Using mixed-effect models, we found that arrival at the colony was influenced by temperature conditions from mid-April to mid-May across all females, but that there were strong and consistent individual differences in arrival- and parturition time across years. Females generally arrived ~32.1 days before giving birth, but the gestation duration was reduced if females arrived late and prolonged if females left the colony when faced with cold weather conditions. Pups born later in the season were born smaller but had higher growth rates during the most rapid growth period (<10 days old). The within-individual effects suggest that the higher growth rates could be due to mothers compensating (e.g. through increased food intake) for late parturition rather than by improved food availability. Date of parturition did not influence adult body size in pups. Pups became volant at the earliest only 13.1 days after birth and approached adult flight patterns during their first flight week. Our results suggest that E. nilssonii is highly adapted to a short breeding season by producing large, fast developing and early volant pups, despite the environmental pressures bats face at northern latitudes.

Repeatability and predictability of lying and feeding behaviours in dairy cattle

Subtle changes in behaviour, which may be useful as early indicators of disease or stress in farm animals, can be detected using precision livestock technologies. However, as animals often display differences in their baseline behaviours from one another, individual variation needs to be measured and accounted for if we want to successfully detect abnormalities. In addition to consistent individual differences in their mean behaviour, which are called behavioural types and measured by repeatability, animals may differ in the amount of day-to-day variation around their own mean. This is known as predictability and it is very rarely measured in animals as it requires data with high granularity for extended periods of time, which is hard to obtain without precision technologies. Here we aim to quantify the repeatability and predictability of lying and feeding, two behaviours which have been investigated as potential indicators of disease with inconsistent results, in dairy cows. We used data on daily lying behaviours from leg-mounted sensors for 2183 cows and data on daily feeding behaviours from neck-mounted sensors for 2584 cows belonging to multiple herds to quantify the variation between individuals, the individual differences in predictability and any correlations between individual behaviour type and predictability of the same behaviour. Using multivariate double hierarchical generalised linear models, we were able to quantify individual variation in feeding and lying behaviours of adult cows for the first time. Consistent variation between individuals was present for all measures of lying and feeding with repeatability values of 0.38 for daily feeding time and 0.31 for daily lying time. Individuals also varied in their levels of predictability with coefficients of 0.46 and 0.29 for the daily lying and feeding time respectively. Lastly, there were significant positive correlations between several behaviours and the amount of residual intra-individual variation for the same behaviour (mean lying bout length: 0.93, mean feeding bout length: 0.88), indicating that cows with the longest bouts of the two behaviours were also more variable and unpredictable, perhaps due to an opportunistic strategy. These results highlight the importance of measuring individual variation in behaviour, supporting the evidence of personality traits in cattle, as well as differences in predictability, which must be taken into account in any use of behavioural indicators for early disease diagnosis.

Bold rats (Niviventer confucianus) are more effective in seed dispersal: evidence both under enclosure conditions and in the field.

Rodents are important seed dispersers of plants because they move seeds far away from the parent trees and hoard seeds in the soil, benefiting seed dispersal and regeneration. Traits of plant seeds and animals are associated with rodent-mediated seed dispersal, but animal personality, the consistent individual behavioral differences in time and environments, has not been fully considered. Here, we first measured the personality of 26 Niviventer confucianus in the laboratory, and 10 individuals in the field of one population, and then tested their behavior of seed consumption and hoarding both in semi-natural enclosures and the field. We tested the hypothesis that individuals with different personalities have different preferences for seed consumption and hoarding, which has different implications for seed dispersal and regeneration. Under the enclosure conditions, all parameters of personality are repeatable; bold individuals harvested fewer seeds but scatter-hoarded more seeds and dispersed farther than timid ones, whereas active individuals consumed more seeds, but left fewer seeds on the ground surface than inactive ones. In the field, boldness, activity, and exploration of the animals are repeatable; bold individuals scatter-hoarded more seeds to farther distances than timid ones, whereas active individuals harvested and consumed more seeds than inactive ones. These results suggest that bold rats tended to scatter hoard seeds and disperse them to a longer distance, implying they are more effective in seed dispersal. In the future, animal personality (e.g. boldness and activity) should be considered in seed dispersal studies and ecological-based manipulation in seed dispersal and regeneration of forests.

Aggressive behavior as a predictor of home range size: findings from both range-restricted and widespread Darwin’s finch species

AbstractInformation about an animal’s home range (the geographical area in which it accesses resources for survival and reproduction) is vital broadly for understanding animal behavior and specifically for developing conservation management plans. Although personality traits—consistent individual differences in behavior across time and contexts—may affect an animal’s home range size, we still lack a breadth of empirical studies across systems to fully appreciate this influence. Here, we tested the relationship between behavioral responses and home range size in two Darwin’s finch species on Floreana Island: the critically endangered and range-restricted Medium Tree Finch (Camarhynchus pauper) and the common and widespread Small Ground Finch (Geospiza fuliginosa). Using a combination of rapid-assessment assays during both short-term captivity and in the field, we measured exploration and aggressiveness in males from both species. We then used radio telemetry to measure each bird’s home range size over a week-long period. We predicted that (1) fast-exploring individuals would have larger home ranges, and (2) more aggressive individuals would have smaller home ranges. We found that Medium Tree Finches had smaller home ranges than Small Ground Finches, that exploratory behavior was positively correlated with home range size only in Small Ground Finches, and that, in both species, individuals’ aggressiveness was negatively correlated with home range size, whereby the more aggressive individuals occupied smaller home ranges. We conclude that behavioral responses that align with major personality traits can predict home range size, which may provide an important tool for the conservation and management of endangered species when, for example, selecting individuals with different personality profiles for reintroduction.

Using diffusion models for symbolic numeracy tasks to examine aging effects.

We present a model-based analysis of aging effects in three symbolic numeracy tasks using three groups of subjects (young adults, 60- to 69-year-olds, and 70- to 90-year-olds). The tasks are number discrimination (is this number greater or less than 50), number memory (was this number in the list of numbers just displayed), and number line (point to where this number is on this number line). The first two tasks were fit by the standard two-choice diffusion model and the last one by the spatially continuous diffusion model (Ratcliff, 2018). Results showed good fits of the models to accuracy (choices) and response time distributions. In the tasks, nondecision time (the time to encode a stimulus and make a response) increased with age, but the amount of evidence needed for a decision (boundary settings) increased in the number discrimination and number memory tasks, but not the number line task. The number discrimination task produced conflicting accuracy and response time results as a function of age, but the model-based analyses resolved these differences. In the number memory task, drift rates (evidence used to drive the decision process) were lower for the older adults than for young adults, but for the other two (easier) tasks, there was no change in drift rate with age. The analyses extracted differences among individuals in model components, some of which were systematic across tasks. In particular, drift rates were correlated across tasks, which shows consistent individual differences across tasks, results that could not have been obtained without model-based analyses. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Personality matters – The interplay between consistent individual differences and mouse welfare in female C57BL6/J mice

To ensure good welfare of animals in human hands, it is essential to modify housing conditions according to the animals’ needs. Traditionally, the effects of such modifications are studied by means of group-level comparisons, thereby widely neglecting consistent inter-individual differences (i.e., so-called ‘animal personalities’). However, as animals with distinct personality types might differ in their environmental needs and hence react differently to the same environment, such systematic inter-individual differences might have important welfare consequences. This becomes particularly apparent under laboratory conditions, where animals are typically housed under highly standardized and barren environments. Against this background, we here aim to investigate personality-dependent welfare consequences in response to different housing conditions in laboratory mice. Female C57BL/6J mice were characterized for their personality type in exploration behavior and the most and the least explorative individuals were set up in either simple or in highly complex housing conditions that included constantly changing environmental enrichment items. We monitored individual welfare by studying behavioral, physiological, and immunological outcome measures. Besides personality-dependent differences in immune parameters and overall improved welfare under complex housing conditions, we indeed found hints that individual mice were differently affected in their welfare depending on the specific combination of personality type and housing condition. Specifically, highly explorative mice appeared to be more adversely affected by simple housing, but also profited more from complex housing compared to low explorative mice. These findings indicate that welfare promoting adjustments do not necessarily benefit all individuals equally and therefore, call for a shift of perspectives in the evaluation of animal welfare.

Openness to experience predicts eye movement behavior during scene viewing

Individuals’ abilities to perform goal-directed spatial deployments of attention are distinguishable from their broader preferences for how they use spatial attention when circumstances do not compel a specific deployment strategy. Although these preferences are likely to play a major role in how we interact with the visual world during daily life, they remain relatively understudied. This exploratory study investigated two key questions about these preferences: firstly, are individuals consistent in their preferences for how they deploy their spatial attention when making shifts of attention versus adopting an attentional breadth? Secondly, which other factors are associated with these preferences? Across two experiments, we measured how participants preferred to deploy both attentional breadth (using an adapted Navon task) and eye movements (using a free-viewing task). We also measured participants’ working memory capacities (Experiment 1), and their personalities and world beliefs (Experiment 2). In both experiments, there were consistent individual differences in preference for attentional breadth and eye movement characteristics, but these two kinds of preference were unrelated to each other. Working memory capacity was not linked to these preferences. Conversely, the personality trait of Openness to Experience robustly predicted two aspects of eye movement behavior preference, such that higher levels of Openness predicted smaller saccades and shorter scan paths. This suggests that personality dimensions may predict preferences for more absorbed engagement with visual information. However, it appears that individuals’ preferences for shifts of attention during scene viewing do not necessarily relate to the breadth of attention they choose to adopt.

Sea anemones (Actinia equina) show consistent individual differences in boldness and thoroughness but lack a behavioural syndrome.

Behavioural syndromes are suites of behaviours that corelate between-individuals but the same behaviours may also show within-individual correlations owing to state dependency or trade-offs. Therefore, overall phenotypic behavioural correlations must be separated into their between- and within-individual components. We investigate how startle response duration (an index of boldness) and time taken to reject an inert item (an index of investigation thoroughness) covary in beadlet sea anemones, Actinia equina. Anemones took longer to reject a more complex item compared to a simpler one, validating this measure of investigation thoroughness. We then quantified between- and within-individual correlations using a Bayesian analysis and an alternative frequentist analysis, which returned the same results. Startle responses decreased with anemone size while thoroughness decreased across repeated observations, indicative of simple learning. For each behaviour, repeatability was significant but relatively low and there was no behavioural syndrome. Rather, the two behaviours showed a negative within-individual correlation in most individuals. Thus, boldness and thoroughness are unlikely to be under correlative selection, and they may instead be expressed independently, in line with the general pattern that cross-contextual behavioural syndromes are comparatively rare. It now appears that this pattern may extend broadly across animal diversity.

Individual differences in face salience and rapid face saccades.

Humans saccade to faces in their periphery faster than to other types of objects. Previous research has highlighted the potential importance of the upper face region in this phenomenon, but it remains unclear whether this is driven by the eye region. Similarly, it remains unclear whether such rapid saccades are exclusive to faces or generalize to other semantically salient stimuli. Furthermore, it is unknown whether individuals differ in their face-specific saccadic reaction times and, if so, whether such differences could be linked to differences in face fixations during free viewing. To explore these open questions, we invited 77 participants to perform a saccadic choice task in which we contrasted faces as well as other salient objects, particularly isolated face features and text, with cars. Additionally, participants freely viewed 700 images of complex natural scenes in a separate session, which allowed us to determine the individual proportion of first fixations falling on faces. For the saccadic choice task, we found advantages for all categories of interest over cars. However, this effect was most pronounced for images of full faces. Full faces also elicited faster saccades compared with eyes, showing that isolated eye regions are not sufficient to elicit face-like responses. Additionally, we found consistent individual differences in saccadic reaction times toward faces that weakly correlated with face salience during free viewing. Our results suggest a link between semantic salience and rapid detection, but underscore the unique status of faces. Further research is needed to resolve the mechanisms underlying rapid face saccades.

Consistent individual differences in behavior among beef cattle in handling contexts and social-feed preference testing

Consistent individual differences (CIDs) in animal behavior, also known as personality or temperament, are measured in a variety of assays and are presumed to represent relatively stable traits of individual animals. Because these behaviors are presumed to represent stable traits, repetition of assays over short and long-term time frames and contexts is crucial; such repetitions are not commonly achieved in literature regarding the topic of CIDs, especially not in a singular study. In beef cattle, CIDs are often related to feeding and social preferences, which is relevant for extensively managed herds of ruminants. This study investigated the consistency of behavior among 50 breeding Angus x Hereford cows across repetitions within one year and over one year during three distinct contexts: handling and isolation in a chute corral system, choice in a social-feed tradeoff test, and response in a novel bucket approach test. We found that cows were consistent across short-term (assessed with repeatabilities [R]) and long-term (assessed with correlations across multivariate models [r]) timeframes in durations of behaviors exhibited in the management context (e.g. while handled [R = 0.60, r = 0.39], while traversing a cement chute [R = 0.69, r = 0.67] and an open squeeze stall [R = 0.76, r = 0.85]). Repeatable behaviors from the handling and isolation in chute system context were input into PCA with varimax rotation. Behaviors loaded onto three principal components that explained 66 % of the variance in the data and distinguished cows along axes of activity, fearfulness and excitability. Cows that were deemed less active (p = 0.010) and less excitable (p = 0.039) chose to approach the supplement bucket over gaining proximity to conspecifics in a social-feed tradeoff test. Even though the cows were not restrained in a squeeze stall, consistent individual differences in behavior across short (within year) and long-term (between years) timeframes were found. This suggests that future research can use unrestrained methods to evaluate cattle temperament, which could improve animal welfare and safety of handlers during experiments. Passive and less excitable beef cattle were more feed-centric, indicating that CIDs in behavior assays could potentially be used to predict feeding behavior because of an underlying stable trait in cows that ties response to handling and management with feed choice in a social-feed tradeoff task.

Effects of age, breeding strategy, population density, and number of neighbors on territory size and shape in Passerculus sandwichensis (Savannah Sparrow)

Abstract The size and shape of an animal’s breeding territory are dynamic features influenced by multiple intrinsic and extrinsic factors and can have important implications for survival and reproduction. Quantitative studies of variation in these territory features can generate deeper insights into animal ecology and behavior. We explored the effect of age, breeding strategy, population density, and number of neighbors on the size and shape of breeding territories in an island population of Passerculus sandwichensis (Savannah Sparrow). Our dataset consisted of 407 breeding territories belonging to 225 males sampled over 11 years. We compared territory sizes to the age of the male territorial holder, the male’s reproductive strategy (monogamy vs. polygyny), the number of birds in the study population (population density), and the number of immediate territorial neighbors (local density). We found substantial variation in territory size, with territories ranging over two orders of magnitude from 57 to 5727 m2 (0.0057–0.57 ha). Older males had larger territories, polygynous males had larger territories, territories were smaller in years with higher population density, and larger territories were associated with more immediate territorial neighbors. We also found substantial variation in territory shape, from near-circular to irregularly-shaped territories. Males with more neighbors had irregularly shaped territories, but shape did not vary with male age, breeding strategy, or population density. For males that lived two years or longer, we found strong consistent individual differences in territory size across years, but weaker individual differences in territory shape, suggesting that size has high repeatability whereas shape has low repeatability. Our work provides evidence that songbird territories are highly dynamic, and that their size and shape reflect both intrinsic factors (age and number of breeding partners) and extrinsic factors (population density and number of territorial neighbors).

Individual behavioural variation does not affect social organization or reproductive success in a cooperative small mammal

Abstract Recent evidence indicates that individual behavioural variation in animals, defined as consistent individual differences in behaviour across contexts and time, influence ecological and evolutionary processes, and a growing number of studies demonstrate that individual behavioural variation can play a large role in shaping grouping dynamics among social animals. We studied the common degu, Octodon degus, a social rodent, to evaluate whether individual behavioural variation underlies social organization and the reproductive success of individuals within groups. We examined social groups in a population in central-north Chile during one breeding season, tested 67 adults in an open field test (i.e., the propensity to explore an unfamiliar environment) and 62 adults in a poke test (i.e., the propensity to charge an object) to quantify individual behavioural variation, determined assortment based on individual behavioural differences across 19 social groups, and performed genetic analyses to assess reproductive success. We found that the response to the poke test was repeatable, while none of the behaviours from an open field test were. The repeatable behaviour during the poke test was not associated to components of social organization (group composition), or to reproductive success. These findings imply that individual behavioural variation did not affect grouping patterns or direct fitness in this degu population.

THINKING STYLES INVENTORY ADAPTATION AND STANDARDIZATION IN LATVIAN

Thinking styles are defined as consistent individual differences in preferred ways of organizing and processing information and experience, thus bridging the gap between personality traits and cognitive processes, meaning, it is more important to understand what abilities people prefer to develop and use, rather than what abilities they have. Thinking styles remain an ongoing area of research in education and psychology, providing insights into students’ experiences and informing educational practices. Latvia still faces a shortage of validated and standardized tests, thus to determine thinking styles, a questionnaire titled “Thinking Style Inventory – Revised II” was selected. This research is a part of a much wider study, which is based on the idea that nowadays the use of the internet and technology form and develop young people’s habits of mind that have not yet been explored. Based on this idea, a research project was established whose overall goal is to discover the impact of young people’s (age 16-25) internet use patterns on cognitive functioning (The impact of internet usage patterns on the development of youth’s cognitive styles, No.: lzp-2021/1-0357). The goal of the specific stage of the study and thus this article is to adapt and standardize the Thinking Style Inventory–Revised II in Latvian. To reach the goal, the questionnaire underwent back and forth translation, then was piloted (n=30), checked for internal consistency, thus concluding the first stage of adaptation. For standardization (n=2169) factoranalysis, discrimination indexes and norms were determined. The results show an overall good internal consistency and the factoranalysis shows similar structure to the original questionnaire. The obtained results indicate that Thinking Style Inventory – Revised II Latvian version can be successfully used to determine thinking styles in Latvia.

Consistent Individual Differences Drive Collective Movements in a Tibetan Macaque Group

Collective movement has emerged as a key area of interest in animal behavior. While individual differences are often viewed as a potential threat to group cohesion, growing evidence suggests that these differences can actually influence an animal’s behavior as an initiator or follower during collective movements, thereby driving the group‘s movement and decision-making processes. To resolve the divergence, we asked how personality can affect the dynamics of collective movements in one group of free-ranging Tibetan macaques (Macaca thibetana) in Huangshan, China. We assessed individual personality using principal component analysis and applied the generalized linear mixed model and linear mixed model to examine the influence of personality on decision making during collective movements. Our findings reveled three distinct personality types among Tibetan macaques: sociability, boldness, and anxiousness. Individuals with higher sociability scores and rank, or those with lower anxiousness scores, were more likely to initiate successful collective movements. Older individuals were less successful in initiating movements compared to young adults. Leaders with lower anxiousness scores or higher rank attracted more followers, with females attracting larger groups than males. As for followers, individuals with higher rank tended to join the collective movement earlier. Additionally, individuals with higher sociability or boldness scores had shorter joining latency in collective movement. Finally, there was a longer joining latency for middle-aged adults compared to young adults. These results suggest that individual differences are a potential driver of collective movements. We provide some insights into the relationships between personality and decision making in Tibetan macaques.

Varying degrees of human-animal interaction elicit weak evidence of a temporally stable behavioral trait in rangeland breeding ewes.

Coherent patterns of inter-related behaviors that occur across time and contexts, also known as personality or consistent individual differences (CIDs), are important to identify among livestock as they carry valuable information for selective breeding purposes. Repeated testing is necessary to reveal behavioral patterns, yet temporal stability of behavioral traits is often assumed. In this study, three human-animal interaction (HAI) tests were employed within a flock of sheep maintained in the Sierra-Nevada foothills to assess intra-individual consistency and inter- relatedness of behavioral responses. Groups of five (four or six when needed) ewes were placed in three HAI tests (restrained Human Contact, unrestrained Human Presence and unrestrained Human Approach) at the time of post-breeding, gestation and weaning (3 x per year; over 2 years). PCs were created using principal component analysis (PCA) of behaviors from the unrestrained Human Presence test and were compared to the behaviors from the two other HAI tests to evaluate cross-contextual relationships. Frequency of ‘environmental vigilance’ (EV), ‘investigating fence’ (IF) and duration of ‘head down’ (HD) were the only variables to achieve a moderate repeatability estimate [EV: 0.32 ± 0.09, [CI (0.21, 0.48])]; IF: 0.29 ± 0.13, [CI (0.14, 0.48)]; HD: 0.44 ± 0.15, [CI (0.22, 0.68)]. PCA revealed a single component in all Human Presence tests that was characterized by loadings (>0.45) for duration of ‘grazing’ and ‘environmental vigilance’. Spearman’s rank order analysis revealed no significant correlations between PC1 of each replicate. There was also no significant inter-relatedness identified between behaviors of each HAI test. Taken together, it is suggested that the rangeland ewes of this study exhibited consistency of some individual behaviors within the Human Contact and Human Presence test, however, did not demonstrate a temporally stable trait that can be generalized across multiple contexts. Future work should evaluate the influence of extensive versus intensive management styles on the development and maintenance of human-oriented behavioral traits.

Cardiac Dynamics in Auditory-Motor Synchronization: Roles of Short-Term Training and Rhythm Complexity

ABSTRACT Previous findings suggest that long-term musical training and rhythm complexity may affect performers’ auditory-motor synchrony and their cardiac rhythms. We investigated the effects of short-term training and rhythm complexity on auditory-motor synchronization and cardiac activity as individuals synchronized with auditory rhythms. Forty-two adult participants synchronized their taps with sounded rhythms to form a 2:3 duration ratio (stimulus duration:tap duration) or a 3:2 duration ratio (tap rate held constant across rhythms). Participants received short training with one rhythm and received longer training with the other rhythm. Then, participants completed five experimental trials in which they synchronized their sounded taps with the stimulus rhythm. Cardiac activity was recorded during synchronization. Tapping synchronization was less accurate and more variable for the 3:2 rhythm than the 2:3 rhythm. Linear measures of cardiac activity showed less high-frequency variability during the 3:2 rhythm than the 2:3 rhythm. Behavioral-cardiac correspondences emerged with training: Poorer synchronization was associated with more variable cardiac activity after long training, but not after short training. Finally, there were consistent individual differences in cardiac recurrence and predictability across training conditions. These findings demonstrate both short-term learning effects and rhythm complexity effects on cardiac dynamics during auditory-motor synchronization.

Do sexes differ in consistent individual differences and behavioural syndrome in an aposematic poison frog?

AbstractThere is a burgeoning interest in studying consistent individual differences in animal behaviour. Most studies consider mainly males, but sexes are subject to distinct selection pressures that may drive differences in life history and therefore lead to differences in a variety of behaviours. Here, we used Oophaga pumilio, a poison frog with sex differences in life‐history strategies (e.g., sex bias in space use and parental care), to explore whether sexes differ or share personality characteristics like behavioural consistency and behavioural syndromes. Based on the natural history of this species, we predicted sex differences in behavioural consistency in exploration but not in boldness, and a correlation between these behavioural traits. We found no sex differences in behavioural consistency in boldness and exploration, although, we observed a tendency of higher consistency in males than females in boldness. When pooling all individuals, we found a higher consistency in boldness than exploration, suggesting the presence of a bold personality in general. We observed a positive between‐individual correlation of boldness and exploration in both sexes indicating the presence of a behavioural syndrome. Our data suggest that selective mechanisms shaping individual behaviour act equally on both sexes in this poison frog.

When slow explorers are fast: Personality‐related differences in timing of migration in Red Knots (Calidris canutus)

The timing of migration varies significantly among individuals, even within populations sharing breeding sites. Consistent individual behavioural differences, known as personality traits, have been linked to variation in movement behaviour. However, little attention has been given to investigating whether personality traits can explain such variation in the timing of migration. We studied post‐breeding migration of Red Knots Calidris canutus islandica breeding in the High Arctic and wintering in European coastal areas. We captured Red Knots in the Dutch Wadden Sea, a main non‐breeding and moulting site, and assessed their exploration behaviour, a personality trait, before releasing them with colour‐rings. We first investigated whether arrival timing in marine areas was associated with exploration speed. Secondly, we asked whether slow explorers were more likely to fly non‐stop to the Wadden Sea compared with fast explorers, as faster explorers were expected to move more and visit more staging sites. To determine arrival timing in marine non‐breeding areas and non‐stop flights to the Wadden Sea, we analysed isotope signatures in blood samples collected after capture, as these differ between the terrestrial breeding grounds (arthropod diet) and marine non‐breeding and moulting sites (benthic invertebrate diet). Thirdly, we estimated arrival time in the Wadden Sea based on primary moult progress, allowing us to examine the relationship between arrival timing estimated from isotope values and the onset of moult. Our findings revealed that slower exploring Red Knots departed earlier from the breeding site and were more likely to fly non‐stop to the Wadden Sea than were faster exploring individuals. Arrival timing to marine areas as estimated from isotope analyses predicted arrival timing in the Wadden Sea (via moult progress) but this relationship exhibited significant variation, possibly due to individual differences in the use of staging sites en route. By migrating early, slower explorers can better outpace the aerial predators also arriving at the Wadden Sea moulting site and thereby reduce mortality risk due to predation.

Consistent individual differences in cattle grazing patterns

Cattle grazing patterns can have a significant impact on the economic and environmental sustainability of rangelands and cattle production. Grazing patterns appear to be driven by consistent individual differences in cattle, deemed ‘grazing personalities’. Optimal distribution of cattle on rangelands can be manipulated by alteration of the environment, like adding water, supplement, or fencing to targeted sites, but few studies address how these management tools are impacting grazing patterns of individual cattle. Our study sought to fill this gap in knowledge by investigating consistency of grazing patterns among fifty cattle, fitted with GPS collars, across two years given the addition of a water site at higher elevation prior to year two. We used Bayesian multivariate mixed models to evaluate consistency, evidenced by among-individual correlations across years with confidence intervals that do not cross 0. We found that cattle were consistent in all rangeland use metrics across years after the addition of the new water site: elevation (Estimate = 0.38, CI = [0.07,0.64]), slope (Estimate = 0.59, CI = [0.21,0.86]), distance to water (Estimate = 0.38 CI = [0.03,0.67]), distance to supplement (Estimate = 0.42, CI = [0.04,0.72]), distance to loafing sites (Estimate = 0.68, CI = [0.24,0.95]), except for distance traveled (Estimate = 0.16,CI = [−0.18, 0.48]). Cows that ventured higher on rangeland in year one (Estimate = 0.84 CI = [0.59,0.98]) and year two (Estimate = 0.93 CI = [0.79,0.99]) and further from watering sites in year two (Estimate = 0.72 CI = [0.41,0.92]) also had more within-individual variability in their grazing patterns than those that stayed at lower elevation and closer to water. These results indicate differences in plasticity or variability can be linked to grazing personalities. There was strong evidence that temperature affected grazing distribution such that on hotter days, cows clumped closer to water and loafing sites, were found at lower elevation, and traveled less far, not reaching supplement sites that were placed at the higher elevations. Based on results of this study, ranchers should consider the effectiveness of management tools on individual cattle and conduct cost-benefit analyses of tools implemented for specific behavior types of cattle. Cattle with behavior types demonstrating more within-cow variability and more ‘hill-climbing’ will impact how cattle graze especially patchy landscapes where resources are distributed across elevation, thus ranchers could potentially match cattle types to rangeland characteristics.

Complexities of consistent individual behavioral differences in effective wildlife management

Complexities of consistent individual behavioral differences in effective wildlife management