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Farine, D. R.

Publications and source records attributed to Farine, D. R..

At least 19 recordsLinked to original sources

Group size influences behavioral plasticity in responses to thermoregulation-foraging trade-offs by a socially cohesive bird

Behavioral plasticity, such as changes in habitat use and activity, can be a critical modulator of thermal pressures on endotherms. However, shifts in behaviors can meet diversified costs such as missed feeding opportunities. Individual decision-making should therefore capture the trade-off between the costs and the benefits of thermoregulation. In the case of social species, the decision process could also be facilitated or slowed down by the modulation of costs arising through the social environment. In this study, we tested how vulturine guineafowl (Acryllium vulturinum) change their use of open areas (where they predominately forage) according to heat using GPS data from 105 birds collected every 5 minutes for 6 months. Because animals vary in their sensitivity to risk according to group size--e.g. due to the dilution effect--we compared the responses of individuals depending on the size of the group they belong to. We also analyzed if behavioral responses translate into less precise thermoregulation by recording the body temperature of a subset of birds in two groups. We foundd that birds avoid heat by selectively using open areas and moving to cover, as well as reducing activity when temperature increases, birds use open areas less and move less. Individuals from intermediate-sized groups seemed to be able to use open areas during warmer conditions compared to individuals from small and large groups (10% higher probability of use). However, active birds in the open did not present hyperthermia, suggesting that behavioral changes are efficient or that individuals have other efficient strategies such as physiological cooling. Together, these results indicated that responses to high temperatures are complex, as they included not only a range of environmental constraints but that responses can also vary according to social context.

ecology↗

Social and spatial drivers of the multitiered structure of zebra finch social networks

Social network structure plays a key role in shaping processes in animal populations. These networks often show distinct patterns in humans and other large mammals, with relationship strengths organized into different tiers. Here, we used continuous, fine-scale tracking of four large captive colonies of zebra finches (Taeniopygia guttata), revealing that zebra finches consistently have 1-2 closest contacts, 6-7 close contacts, and 22-24 strong contacts. The identities of these contacts remain stable across days, with strong contacts maintained by spatial affinity while closest and close contacts are maintained by social choice. These results suggest that zebra finches egocentric networks and social structure are made up of consistent, differentiated relationships forming a multitiered social structure. The similarities in patterns to other species suggest that fundamental principles, such as limitations in time and the ability to move through social space, could drive common structural properties in animal social networks.

animal behavior and cognition↗

Foraging associations are related with helping interactions in a cooperatively breeding bird

Kin selection has been the main hypothesis explaining helping behaviour in cooperative breeders, with evidence being largely based on the observation that helpers tend to provide to related offspring. However, kin-biased help could conceal additional, mechanisms contributing to the maintenance of cooperation. Under pay-to-stay, group augmentation and partner choice hypotheses, a range of direct benefits can arise through helping. Here, we explored this potential mechanism by testing whether the social associations of breeding individuals were related with the help that they received from non-breeding individuals. We collected social associations from PIT-tagged sociable weavers, Philetairus socius, at RFID feeding stations, which allowed us to compare associations between breeders and either their helpers (mostly kin) or their other kin that did not help--before, during and after reproduction. Using correlative tests and data-driven simulations, we show that helpers have stronger foraging bonds with breeders than non-helping kin, and that these stronger bonds are present both prior and post breeding. Furthermore, helper-breeding female social affiliations were positively correlated with the amount of help provided. Our results suggest that direct benefits of social associations complement kin selection to determine helping decision, and that these in turn influence future social associations.

animal behavior and cognition↗

Low-cost animal tracking using Bluetooth low energy beacons on a crowd-sourced network

O_LIAnimal tracking has opened the door to address many fundamental questions in ecology and conservation. While historically animals have been tracked as a means to understand their large-scale movements, such as migration, there is now a greater focus on using tracking to study movements over smaller scales, individual variation in movement, or how movements shape social network structure. With this shift in focus also comes different tracking needs, including the need to track larger numbers of individuals. C_LIO_LITracking studies all face some technological limitations. For example, GPS and other active tracking solutions can collect fine-scale movement data, but have a high cost per tag, limiting the number of individuals that can be followed. They also have high energy costs of data acquisition and download, limiting time periods over which data can be collected. Low-energy passive (e.g. PIT) or active (e.g. reverse GPS) tags can overcome these limitations, but instead require animals to remain within a bounded study area or to come into close proximity to detectors. C_LIO_LIHere we describe one solution that can overcome many current limitations by employing the massive global network of personal mobile phones as gateways for tracking animals using Bluetooth low energy (BLE) beacons. In areas with medium to high density of people, these simple-to-make beacons can provide regular updates of position over long time periods (battery life 1-3 years). We describe how to use off-the-shelf components to produce BLE beacons that weigh c. 5-6 g and cost < $7USD. Using field testing, we then show that beacons are capable of producing high-frequency tracking data that can be used to build home ranges or to detect spatio-temporal co-occurrences among individuals. C_LIO_LIBLE beacons are a low cost, low energy solution for studying organisms (e.g. birds, mammals, and reptiles) living and moving in urban landscapes. Their low weight and small size makes them particularly well-suited for tracking smaller species. When combined with fixed gateways, their use can also be extended to non-urban habitats. Their high accessibility is likely to make them an attractive solution for many research projects. C_LI

animal behavior and cognition↗

Density-dependent network structuring within and across wild animal systems

High population density should drive individuals to more frequently share space and interact, producing better-connected spatial and social networks [1-4]. Although this theory is fundamental to our understanding of disease dynamics [2,5-8], it remains unconfirmed how local density generally drives individuals positions within their networks, which reduces our ability to understand and predict density-dependent processes [4,9,10]. Here we provide the first general evidence that density drives greater network connectedness at fine spatiotemporal scales, at the scale of individuals within wild animal populations. We analysed 36 datasets of simultaneous spatial and social behaviour in >58,000 individual animals, spanning 30 species of fish, reptiles, birds, mammals, and insects. 80% of systems exhibited strong positive relationships between local density and network centrality. However, >80% of relationships were nonlinear and 75% became shallower at higher values, signifying that demographic and behavioural processes counteract densitys effects, thereby producing saturating trends [11-15]. Densitys effect was much stronger and less saturating for spatial than social networks, such that individuals become disproportionately spatially connected rather than socially at higher densities. Consequently, ecological processes that depend on spatial connections (e.g. indirect pathogen transmission, resource competition, and territory formation) are likely more density-dependent than those involving social interactions (e.g. direct pathogen transmission, aggression, and social learning). These findings reveal fundamental ecological rules governing societal structuring, with widespread implications. Identifying scaling rules based on processes that generalise across systems, such as these patterns of density dependence, might provide the ability to predict network structures in novel systems.

ecology↗

Using an agent based model to inform sampling design for animal social network analysis

Producing accurate and reliable inference from animal social network analysis depends on the sampling strategy during data collection. An increasing number of studies now use large-scale deployment of GPS tags to collect data on social behaviour. However, these can rarely capture whole populations or sample at very high frequencies. To date, little guidance exists when making prior decisions about how to maximise sampling effort to ensure that the data collected can be used to construct reliable social networks. We use a simulation-based approach to generate a functional understanding of how the accuracy of various network metrics is affected by decisions along three fundamental axes of sampling effort: coverage, frequency and duration. Researchers often face trade-offs between these three sampling axes, for example due to resource limitations, and thus we identify which axes need to be prioritised as well as the effectiveness of different deployment and analytical strategies. We found that the sampling level across the three axes has different consequences depending on the social network metrics that are estimated. For example, global metrics are more sensitive than local metrics to the proportion of the population tracked, and that among local metrics some are more sensitive to sampling duration than others. Our research demonstrates the importance of establishing an optimal sampling configuration for drawing relevant and robust inferences, and presents a range of practical advice for designing GPS based sampling strategies in accordance with the research objectives.

ecology↗

Long-term stability of dominance hierarchies in a wild parrot with fission-fusion dynamics

Dominance hierarchies are a common feature of stable groups, allowing animals to limit the costs of fighting over access to resources. However, while the emergence of dominance is relatively well known from species that form stable groups, less is known about whether hierarchies are maintained in societies with open group membership. One challenge for species that live in an open social environment is that they have the possibility of engaging in dominance interactions with a large number of conspecifics. To better understand how animals navigate the complexities of interacting within a large, open society, we recorded social associations and aggressive interactions in a highly social, communally roosting parrot, the sulphur-crested cockatoo (Cacatua galerita). By following 515 individuals across three neighbouring communities and recording social interactions during foraging, we show that sulphur-crested cockatoos form clear, linear hierarchies. We find males rank higher than females and that adults rank higher than juveniles. Within sex, where individuals may still have to compete with up to 100 individuals from the same age-sex class, body size did not affect dominance rank. Finally, we find that, despite highly dynamic social associations (fission-fusion dynamics) among individuals, hierarchies are stable, with dominance ranks being highly repeatable across at least three years. This study demonstrates that closed group membership is not a pre-requisites for stable dominance hierarchies to emerge.

animal behavior and cognition↗

Collective intelligence facilitates emergent resource partitioning through frequency dependent learning

Deciding where to forage must not only account for variation in habitat quality, but also where others might forage. Recent studies have suggested that when individuals remember recent foraging outcomes, negative frequency-dependent learning can allow them to avoid resources exploited by others (indirect competition). This process can drive the emergence of consistent differences in resource use (resource partitioning) at the population level. However, indirect cues of competition can be difficult for individuals to sense. Here, we propose that information pooling through collective decision-making--i.e. collective intelligence--can allow populations of group-living animals to more effectively partition resources relative to populations of solitary animals. We test this hypothesis by simulating (i) individuals preferring to forage where they were recently successful, and (ii) cohesive groups that choose one resource using a majority rule. While solitary animals can partially avoid indirect competition through negative frequency-dependent learning, resource partitioning is more likely to emerge in populations of group-living animals. Populations of larger groups also better partition resources than populations of smaller groups, especially in environments with more choices. Our results give insight into the value of long- vs. short-term memory, home range sizes, and the evolution of specialisation, optimal group sizes, and territoriality.

ecology↗

The contribution of movement to social network structure and spreading dynamics under simple and complex transmission

The structure of social networks fundamentally influences spreading dynamics. In general, the more contact between individuals, the more opportunity there is for the transmission of information or disease to take place. Yet, contact between individuals, and any resulting transmission events, are determined by a combination of spatial (where individuals choose to move) and social rules (who they choose to interact with or learn from). Here we examine the effect of the social-spatial interface on spreading dynamics using a simulation model. We quantify the relative effects of different movement rules (localized, semi-localized, nomadic, and resource-based movement) and social transmission rules (simple transmission, anti-conformity, proportional, conformity, and threshold rules) to both the structure of social networks and spread of a novel behaviour. Localized movement created weakly connected sparse networks, nomadic movement created weakly connected dense networks, and resource-based movement generated strongly connected modular networks. The resulting rate of spreading varied with different combinations of movement and transmission rules, but-- importantly--the relative rankings of transmission rules changed when running simulations on static versus dynamic representations of networks. Our results emphasize that individual-level social and spatial behaviours influence emergent network structure, and are of particular consequence for the spread of information under complex transmission rules.

animal behavior and cognition↗

Moving as a group imposes constraints on the energetic efficiency of movement.

Movement is a key part of life for both solitary and group-living animals. In solitary animals, the energetic costs of making large displacements can be mitigated by energetically efficient strategies--specifically faster, straighter movements. However, little is known about whether moving as part of a collective enhances or limits the ability for individual group members to express such strategies. Drawing on 6 years of population-level high-resolution (1Hz) GPS tracking of group-living vulturine guineafowl (Acryllium vulturinum), we detected 886 events from 94 tagged individuals where their groups made large displacements, shifting their home ranges in response to changing environmental conditions. We contrasted these movements with data with 94 large displacement events by 19 lone, dispersing individuals. Our results suggest that individuals moving as part of group can significantly reduce their energetic cost of transport when making large displacements (15.5% reduction relative to their normal daily ranging behaviours) by increasing the speed and straightness of their movements. However, even during their most-efficient movements, individuals in groups could not achieve or maintain the same increases in speed that others could when moving alone, resulting in significantly limited efficiency gains (solitary individuals were 34.9% more efficient than individuals in groups). Overall, this study provides evidence for a substantial, and previously hidden, energetic cost arising from collective movement.

ecology↗

Habitat selection during dispersal reduces the energetic cost of transport when making large displacements

Dispersal is energetically costly. However, there is now growing evidence that dispersing animals can express distinct movement strategies that allow them to mitigate most of the energetic costs of displacing over large distances. Whilst to date we know that these strategies involve changes in how dispersing animals move, it is unclear whether these changes in movement are facilitated by other components of behaviour--namely changes in habitat selection. Here, we combine step-selection analyses with models of the energetic costs of movement to high-resolution GPS tracking data in terrestrially dispersing vulturine guineafowl (Acryllium vulturinum) to test the hypothesis that dispersing animals should select for habitats that facilitate more energetically efficient movements during dispersal. We find that actively dispersing individuals exhibit increased positive selection for open habitats, especially roads. We then show that moving along roads facilitates straighter, faster movements and results in a more than 33% reduction in the energetic cost of transport relative to other habitat types. Our results confirm that fine-scale differences in habitat selection expressed by dispersers facilitate more energetically efficient movement, expanding our understanding of how animals exhibit adaptive movement strategies across different axes of decision-making (e.g., where and how to move) to overcome ecological challenges.

ecology↗

The physiological costs of spatial positioning and leadership in collective movements

Individuals can gain substantial benefits from collective actions1-7. However, collective behaviours introduce new challenges, like coordinating actions, maintaining cohesion, and meeting the needs of different individuals. When making collective movements, leaders are typically thought to gain disproportionate benefits through the choice of more beneficial resources3 and/or earlier access to resources8. However, reaping these benefits can also have costs. Being at the front of a group can increase physical exertion4,9,10 and predation risk11,12. Moreover, ending up in a leadership position (i.e., at the front), is a process of negotiation in many animal groups. Within-group differences in directional preferences are typically resolved by some individuals initiating directional movements, after which they are either followed (if they are successful in leading) or return to the group (if they fail)13-30. By combining data on movement initiations (using whole-group GPS tracking31 and individual heart rate from implanted ECG loggers) in wild vulturine guineafowl, we found significant increases in heart rate (and decreases in heart rate variability) during collective movements. We found that attempting--and failing--to initiate directional movement was particularly costly, with the highest costs when consensus among group members was low and when individuals acted against the majority. Increases in heart rate and decreases in its variability can indicate physiological stress, entailing increased energy expenditure and long-term physiological damage. These results suggest that behaviours often thought beneficial to individuals (by influencing group behaviours) are also physiologically costly, representing a constraint on group-living and explaining why sometimes individuals opt out of contributing to leadership.

ecology↗

Social decision-making in a wild parrot relies on both individual recognition and intrinsic markers

O_LIDominance hierarchies are generally thought to form over time via memory of repeated interactions. However, dominance hierarchies are also occasionally reported in species with fission-fusion social dynamics, where individuals may encounter large numbers of individuals, leading to incomplete social information. It it has been alternatively proposed that the complex decision-making required in these circumstances may lead to increased selection for social cognition and memory, or to the evolution of mixed strategies that rely on memory for interaction with familiars and status signals for strangers. C_LIO_LIHere, test these competing hypotheses by recording social associations and aggressive interactions in a highly social, large-brained parrot, the sulphur-crested cockatoo ( Cacatua galerita). We followed 411 individuals across three neighbouring roost sites, where individuals exhibit stable dominance hierarchies within roosts, alongside a high degree of fission-fusion dynamics within roosts and regular between-roost movements. C_LIO_LIWe found evidence that sulphur-crested cockatoos use a two-fold social strategy when initiating or reacting to an aggression. For familiar individuals, aggressions were initiated or escalated based on rank difference. When facing less familiar individuals, decisions to interact -- or escalate -- were based on the relative weight, with interactions directed towards, and more likely to escalate between, individuals of similar weight. C_LIO_LIOur results suggest that social knowledge remains an important determinant of aggressive interactions in highly fission-fusion systems, but that individuals can dynamically incorporate other potential cues of competitive ability when knowledge is lacking. C_LI

animal behavior and cognition↗

Breeding alters females' social positions by changing dominance dynamics

Agonistic and affiliative interactions with group members dictate individuals access to resources, and investment in competing for resources is often traded off with other needs. For example, reproductive investment can reduce body condition and, thereby, an individuals ability to win future agonistic interactions. However, group members may also alter their behaviour towards reproductive individuals, such as becoming more or less aggressive. Here, we investigated the social consequences of reproduction in female vulturine guineafowl Acryllium vulturinum, a plural breeder in which females disperse and are subordinate to males. We found opposing patterns for breeders within- and between-sex dominance interactions from before to after breeding. Specifically, while breeding females became far less likely to win dominance interactions with non-breeding females after breeding than before breeding, they received considerably fewer male aggressions than non-breeding females after breeding. Using agent-based models, we then show that hierarchies inferred using the Percolation and Conductance method are robust to such variation in interaction rates, while other common methods may be prone to systematically overestimating or underestimating particular individuals hierarchy positions. Our study highlights reproduction as a driver of dominance dynamics, and illustrates how the study of dominance may benefit from considering variation in interaction rates.

animal behavior and cognition↗

Cooperative breeding in a plural breeder: the vulturine guineafowl (Acryllium vulturinum)

Cooperative breeding is widely reported across the animal kingdom. In birds, it is hypothesised to be most common in altricial species (where chicks are dependent on parental care in the nest after hatching), with few described cases in precocial species (where chicks are more independent immediately after hatching). However, cooperative breeding may also be more difficult to detect in precocial species and therefore has been overlooked. In this study, we investigate whether vulturine guineafowl (Acryllium vulturinum)--which have precocial young--breed cooperatively and, if so, how care is distributed among group members. Using data collected from colour-banded individuals in one social group of vulturine guineafowl over three different breeding seasons, we found that multiple females can attempt to reproduce in the same breeding season. Broods had close adult associates, and most of these associates exhibited four distinct cooperative breeding behaviours: babysitting, within-group chick guarding, covering the chicks under the wings and calling the chicks to food. Further, we found that offspring care is significantly male-biased, that non-mother individuals provided most of the care each brood received, that breeding females differed in how much help they received, and that carers pay a foraging cost when providing care. Our results confirm that vulturine guineafowl are cooperative breeders, which they combine with an unusual plural-breeding social system. Our study also adds to growing evidence that cooperative breeding may be more widespread among species with precocial young than previously thought, thereby providing a counterpoint to the altriciality-cooperative breeding hypothesis.

animal behavior and cognition↗

Beyond the dyad: uncovering higher-order structure within cohesive animal groups

Revealing the consequences of social structure in animal societies is largely determined by our ability to accurately estimate functionally relevant patterns of social contact among individuals. Of particular relevance are social contacts that drive and maintain the cohesion of moving animal groups. To date, studies have predominantly built up social structure from dyadic connections, which while effective in open societies--where groups are ephemeral--may not be sufficient to characterise the fine-grained structure within more cohesive animal groups. This is because associations or interactions can involve more than two individuals participating together, which current approaches cannot distinguish from independent sets of dyadic connections. Here we apply higher-order temporal network approaches to high-resolution GPS data from every group member in two cohesive groups of vulturine guineafowl (Acryllium vulturinum). By quantifying moment-by-moment association dynamics, we reveal clear sex-biased contributions to the group cohesion. Specifically, males form the cohesive core of the group as they participate in temporally consistent sub-groups and tend to occupy forward positions when in movement. Females instead remain peripheral and are more likely to leave sub-groups, while also occupying rear positions in moving sub-groups. These results reveal how the cohesion among males, which were previously found to be more likely to lead group movements, allows them to more often form a majority, confirming that self-organisation within the group can drive leadership patterns independently of dominance. Our study thus demonstrates that sub-group association dynamics derived from high-resolution GPS data can provide insights in how the fine-scale spatial and social organisation of cohesive groups, and their temporal dynamics, can explain key processes like leadership.

animal behavior and cognition↗

A guide to using GPS-based tracking to study animal societies

GPS-based tracking is widely used for studying wild social animals. Much like traditional observational methods, using GPS devices requires making a number of decisions about sampling that can affect the robustness of a studys conclusions. For example, sampling fewer individuals per group across more distinct social groups may not be sufficient to infer group- or subgroup-level behaviours, while sampling more individuals per group across fewer groups limits the ability to draw conclusions about populations. Here, we provide quantitative recommendations when designing GPS-based tracking studies of animal societies. We focus on the trade-offs between three fundamental axes of sampling effort: 1) sampling coverage--the number and allocation of GPS devices among individuals in one or more social groups; 2) sampling duration--the total amount of time over which devices collect data; 3) sampling frequency--the temporal resolution at which GPS devices record data. We first test GPS tags under field conditions to quantify how these aspects of sampling design can affect both GPS accuracy (error in absolute positional estimates) and GPS precision (error in the estimate relative position of two individuals), demonstrating that GPS error can have profound effects when inferring distances between individuals. We then use data from whole-group tracked vulturine guineafowl (Acryllium vulturinum) to demonstrate how the trade-off between sampling frequency and sampling duration can impact inferences of social interactions and to quantify how sampling coverage can affect common measures of social behaviour in animal groups, identifying which types of measures are more or less robust to lower coverage of individuals. Finally, we use data-informed simulations to extend insights across groups of different sizes and cohesiveness. Based on our results, we are able to offer a range of recommendations on GPS sampling strategies to address research questions across social organizational scales and social systems--from group movement to social network structure and collective decision-making. Our study provides practical advice for empiricists to navigate their decision-making processes when designing GPS-based field studies of animal social behaviours, and highlights the importance of identifying the optimal deployment decisions for drawing informative and robust conclusions.

animal behavior and cognition↗

Cooperative breeding and the emergence of multilevel societies in birds

Multilevel societies (MLSs), where social levels are hierarchically nested within each other, are considered one of the most complex forms of animal societies. Although thought to mainly occur in mammals, it is suggested that MLSs could be under-detected in birds. Here we propose that the emergence of MLSs could be common in cooperatively breeding birds, as both systems are favoured by similar ecological and social drivers. We first investigate this proposition by systematically comparing evidence for multilevel social structure in cooperative and non-cooperative birds in Australia and New Zealand, global hotspots for cooperative breeding. We then analyse non-breeding social networks of cooperatively breeding superb fairy-wrens (Malurus cyaneus) to reveal their structured multilevel society, with three hierarchical social levels that are stable across years. Our results confirm recent predictions that MLSs are likely to be widespread in birds and suggest that these societies could be particularly common in cooperatively breeding birds.

ecology↗