Group-living animals must coordinate with other group members to reap the benefits and avoid the costs of social living, but precisely how individuals should respond to one another is mediated by interacting social and environmental factors. In stable groups, familiarity (i.e. prior experience with particular conspecifics) often improves group coordination, with familiar groups outperforming unfamiliar groups in foraging efficiency and predator evasion. Group coordination is also affected by individual behavioural tendencies, and consistent individual differences such as boldness drive specific coordination behaviours including leadership. Furthermore, in stable groups these consistent differences in behaviour (or ‘personalities’) facilitate individuals predicting each other’s behaviour as they can learn their groupmates’ behavioural tendencies over time. Few studies have investigated how familiarity and personality interact to influence behaviour in social groups. Here, we assess how familiarity differentially affects ‘bold’ and ‘shy’ individuals in pairs of three-spined sticklebacks ( Gasterosteus aculeatus ). Our results show that familiarity modifies how individuals coordinate with their partners, and that leadership dynamics are determined by boldness levels in unfamiliar pairs, but not in familiar pairs. This suggests that familiarity with others in social groups alters the leadership tendencies of individuals, with implications for how personality interacts with the social environment to determine individual coordination behaviour.
Understanding how animals maximize reproductive success in variable environments is important in determining how populations will respond to increasingly extreme weather events predicted in the face of changing climates. Although temperature is generally considered a key factor in reproductive decisions, rainfall is also an important predictor of prey availability in arid environments. Here, we test the impact of weather (i.e., rainfall and temperature) on female reproductive investment in an arid-dwelling bird (i.e., clutch size and egg volume) and tradeoffs between the two. We predicted that female chestnut-crowned babblers (Pomatostomus ruficeps), endemic to the arid region of Australia, would increase clutch size at the expense of egg volume in response to variation in rainfall and temperature. We found that over 14 breeding seasons, clutch size decreased with increasing temperature, but increased following more rain. Egg volume, on the other hand, became larger as temperatures increased and, although not related to the amount of rain, was related to the number of days since the last rainfall. Finally, egg size decreased as clutch size increased, indicating a tradeoff between the two reproductive parameters. Our results suggest that chestnut-crowned babblers breed reactively in response to variable environments. We expect that clutch size variation in response to rain may reflect the impact of rain on arthropod abundance, whereas the effect of temperature may represent an established decline in clutch size observed in other seasonal breeders. As the tradeoff between clutch size and egg volume was modest and clutch sizes were modified to a greater extent than egg volumes in response to rainfall, we suggest selection is more likely to increase offspring number than quality, at least in favorable years. Our results support the idea that reproductive investment is variable in fluctuating environments, which has implications for species living in habitats experiencing more extreme and less predictable weather as the global climate changes.
Animals can gain large benefits from living in groups but must coordinate with their groupmates in order to do so. Social interactions between groupmates drive overall group coordination and are influenced by the characteristics of individual group members. In particular, consistent inter-individual differences in behaviour (e.g. boldness) and familiarity between individuals in groups profoundly affect the individual interactions that mediate group coordination. However, the effects of boldness and familiarity have mostly been studied in isolation. Here we describe how familiarity and boldness interact to affect individual performance, leadership, and group coordination in small shoals of three-spined sticklebacks (Gasterosteus aculeatus) solving a novel foraging task. Groups of higher average boldness were less cohesive, but only when group members were familiar with one another. Familiarity affected shy and bold individuals’ foraging performance and leadership tendencies differently depending on group characteristics: the shyest group member experienced declining foraging success and leadership with increased group boldness in familiar groups, but experienced the opposite effect on foraging and no effect on leadership in unfamiliar groups. The boldest group member, in contrast, exhibited the opposite pattern: leading and eating more with increasing group boldness in familiar groups, but eating less with increasing group boldness in unfamiliar groups. These results suggest that both boldness and familiarity are important for establishing group behaviour and coordination, and that consistent inter-individual differences in behaviour may primarily impact group coordination once familiarity has been established.
In many endangered species, reproductive failure is a major barrier to recovery. The critically endangered kākāpō ( Strigops habroptilus ) exemplifies this challenge: 61% of their eggs fail to hatch, and of these 73% show no sign of development. Undeveloped eggs have previously been attributed to male infertility, but recent studies of non-threatened bird species suggest fertilisation failure is rare in the wild. The underlying causes of fertilisation failure and embryo death differ, so distinguishing between them is essential for effective conservation management. Here we show that the majority (72%, n=124) of undeveloped kākāpō eggs are fertilised, and combine this with conservation programme data on natural copulations, artificial inseminations, and paternity of developed eggs, to generate the most precise estimate to date of fertility in a wild population. We also demonstrate, for the first time in a wild bird, that artificial insemination results in greater numbers of sperm reaching the egg.
EDITORIAL article Front. Ecol. Evol., 07 December 2020 | https://doi.org/10.3389/fevo.2020.614863
In many species, individuals must contribute extensively to offspring care to reproduce successfully. Within species, variation in care is driven by local social, physiological, and environmental contexts, and this relationship has been a major focus of behavioral ecology since the inception of the field. The majority of existing studies on care, both theoretical and empirical, have focused on measuring the amount of care delivered by each carer as a proxy for individual investment, linking this investment to the local context, and investigating outcomes for offspring. However, more recently interest has grown in the finer-scale details of care, including how individuals respond to each other's behavior, and temporal variation in care both within and between stages. Simultaneously, advances in remote monitoring methods, such as video cameras and passive integrated transponder (PIT) tag systems, have vastly increased the ease of collecting large amounts of care data, providing opportunities to study carer behavior in much greater detail than previously possible. In this mini-review we provide an overview of the dimensions of carer behavior that can be quantified, illustrated using recent studies from a variety of taxa. We classify these analyses into three broad groups: (a) how parental care is distributed in time, (b) variation within care events, and (c) how carers interact when jointly providing care. Our aim is to encourage more in-depth analyses of parental care, to build a more complete picture of how animals rear their offspring.
Sexual conflict is inescapable when two parents care for offspring, because providing care is personally costly, while the benefits of successful reproduction are shared. Previous models that treat parental investment as a continuous trait, with stable levels of effort negotiated between parents over evolutionary or behavioral time, generally predict that sexual conflict will lead to under-investment in the young, as each parent stands to gain by leaving its partner to bear a greater share of the costs of care. More recently, a model of parental investment as repeated discrete contributions suggested that a more efficient outcome can be reached through parents adopting a simple strategy of conditional cooperation by "turn-taking": only investing after each contribution by their partner. However, while empirical work suggests that parental visits are significantly alternated in a number of natural systems, all examples thus far exhibit imperfect turn-taking rather than the strict rule predicted by theory. To help bridge this gap, we here present a more realistic mathematical model of parental turn-taking, incorporating (i) errors in parents' ability to monitor the contributions of their partner, (ii) time-dependent costs and benefits of delivering care, (iii) differences between partners in payoffs (and consequently in behavior), (iv) differences between partners in the accuracy with which they can monitor one another's behavior, and (v) shared costs of care. We illustrate how the degree of conditional cooperation is influenced by each of these factors, and discuss ways in which our model could be tested empirically.
Supporting good practice in Research Data Management (RDM) is challenging for higher education institutions, in part because of the diversity of research practices and data types across disciplines. While centralised research data support units now exist in many universities, these typically possess neither the discipline-specific expertise nor the resources to offer appropriate targeted training and support within every academic unit. One solution to this problem is to identify suitable individuals with discipline-specific expertise that are already embedded within each unit, and empower these individuals to advocate for good RDM and to deliver support locally. This article focuses on an ongoing example of this approach: the Data Champion Programme at the University of Cambridge, UK. We describe how the Data Champion programme was established; the programme’s reach, impact, strengths and weaknesses after two years of operation; and our anticipated challenges and planned strategies for maintaining the programme over the medium- and long-term.
One of the primary functions of animal aggregations is defence against predators. Many social animals enjoy reduced predation risk as a result of grouping, and individuals within groups can benefit from information transferred by their group-mates about a potential predator. We present evidence that a tactile interaction behaviour we term "nudging" substantially modified group responses to a potential threat in a highly social catfish, Corydoras aeneus. These catfish deployed nudges during flight responses, and these nudges were associated with a greater likelihood of group cohesion following a threat event. Increased nudging behaviour also resulted in longer flight responses, a potentially costly outcome in natural contexts. In addition, individuals that perceived the threat first were more likely to initiate nudges, implying that nudges could be used to alert group-mates to the presence of a threat. Taken together, our results suggest that tactile communication plays an important role in mediating anti-predator benefits from sociality in these fish.
Many young birds die soon after fledging, as they lack the skills to find food and avoid predation. Post-fledging parental care is assumed to assist acquisition of these vital skills. However, we still lack empirical examples examining the length of time fledglings spend with parents, how they associate during this critical time, or whether such variation in the fledgling dependency period has consequences for the survival and behaviour of young as they navigate their first year of independent life. Here, we make use of observations and radio frequency identity (RFID) logs of visits to supplementary feeding stations to investigate how condition of fledgling hihi (stitchbird, Notiomystis cincta), a New Zealand passerine, predicts dispersal behaviour and tendency to follow parents during their 2 week post-fledging dependence period. We find that thinner fledglings followed their parents more closely in time when visiting feeding stations, compared to fatter siblings (all following ranged from 3 s to 10 min). However, broods in poorer condition tended to disperse from the natal territory up to 6.5 days earlier than broods of fatter fledglings (all dispersed within 14 days). Our results did not find that sociality or survival during the first year of life differed depending on variation in fledgling behaviour; neither following parents closely nor dispersing later predicted each bird's number of associates (degree), or survival over winter. These results suggest that fledglings may be able to compensate for early differences in condition with behaviour, either during the post-fledging dependence period or when independent.
Ornithology has a venerable history. Worldwide, birds are both culturally important and one of the most salient reminders of the natural world, and beyond their regular appearances in folklore, literature and art they were among the first subjects of natural history from the classical world to the Renaissance. The study of birds remained a fixture of inquiry through the scientific revolution: Philosophical Transactions of the Royal Society, the oldest scientific journal still published, included ornithological method papers in its very first volume (Boyle 1666), and as scientific practice developed ornithological research kept pace. A growing interest in the diversity and systematics of birds ultimately led to the formation of dedicated ornithological societies and journals in the second half of the nineteenth century. First were the Society of German Ornithologists (Deutsche OrnithologenGesellschaft) in 1850 and the British Ornithologists’ Union in 1858; their respective journals ‘Journal für Ornithologie’ (now ‘Journal of Ornithology’) and ‘Ibis’ followed in 1853 and 1859. In America, the American Ornithologists’ Union was founded in 1883 with its journal ‘Auk’ beginning the same year, followed by the Wilson Ornithological Society (1886) and Cooper Ornithological Club (1893) and their journals shortly thereafter. The Royal Australasian Ornithologists’ Union (now part of BirdLife Australia) was founded in 1901, along with its journal ‘Emu’. Amazingly, all these publications are still extant, and digital versions of much of their content are now available back to their first issues. In common with other branches of science, ornithological research has exploded in recent decades, and with this plethora of new work, it is tempting to disregard the older corpus of knowledge, under the assumption that it has either been superseded or is too far removed from modern practice to be useful. However, with over 10 000 extant bird species worldwide and the avifauna of many regions still rarely studied, we would encourage the ornithological community to not overlook earlier literature. In this note, we illustrate the potential interest and value of older studies using three diverse articles published in a single journal issue 100 years ago: volume nineteen of Emu.
1. I don’t have time for this! My PhD is too short to deal with this additional work. As long as I produce publications and a thesis I will be fine. 2. I know my own data and can navigate it it without any problems.3. I know my data, you don’t. 4. Time cost: Backing up 5. Monetary cost: Have to pay for service base, need to buy my own external hard drive 6. I don’t understand data management. 7. It is my own project. I am the only one doing this research and I'm happy with it. Why should I do anything differently?
Recent theoretical and empirical work suggests that coordinating offspring provisioning plays a significant role in stabilising cooperative care systems, with benefits to developing young. However, a warming and increasingly extreme climate might be expected to make contributions to, and so coordination of, care more challenging, particularly in cooperative breeding systems comprising multiple carers of varying age and pair-wise relatedness. Here we investigated the interplay between breeding phenology, meteorological conditions and carer number on the individual rates and group-level of coordination of nestling care in the cooperatively breeding chestnut-crowned babbler (Pomatostomus ruficeps) in outback south-eastern Australia. From three months since the last meaningful rain event, dominant male breeders and – to a lesser extent – related helpers showed reductions in their provisioning rates and increases in their day-to-day variation. On days with high mean wind speed, dominant males contributed less and helpers were less likely to visit the nest on such days, and also showed reduced visitation rates on days with high mean temperature. Provisioning rates were independent of the number of carers, and increasing numbers of carers failed to mitigate the detrimental effects of challenging environment on patterns of provisioning. Those helpers that were unrelated to broods often failed to help on a given day and tended to help at a low rate when they did contribute, with socio-environmental predictors having limited explanatory power. Given the marked variation in individual contributions to offspring care and the variable explanatory power of the socio-environmental predictors tested, babblers unsurprisingly had low levels of nest-visitation synchrony. Large groups visited the nest more asynchronously on days of high mean temperature, suggesting that meteorological impacts on individual provisioning have consequences for group-level coordination. Our study has implications for the consequences of climate change on patterns of provisioning, the minimal role of group size in buffering against these challenges and the stabilisation of cooperative care.
In bi-parental care systems each parent shares benefits with its unrelated partner from the common investment in offspring, but pays an individual cost of providing that care, leading to sexual conflict. However, several recent empirical studies have shown that coordinating behaviours like synchronisation (e.g., arriving at similar times) and alternation (taking turns in providing care) at the nest lead to increased investment overall, presumably to reduce conflict through policing or synergistic benefits. Ecological conditions should impact the costs and benefits of bi-parental care, yet there exists a gap in research on the relationship between ecological conditions and patterns of parental care behaviour beyond visitation rate. Here we provide an examination of how bi-parental provisioning behaviours, i.e., pair feeding rate and feeding consistency, and the degree to which parents synchronise or take turns, differ under contrasting ecological conditions in populations of blue tits (Cyanistes caeruleus) spanning a 1,000 m altitudinal gradient. We found that blue tit pairs synchronised and alternated more than expected by chance, and that care patterns were modified by ecology. Pairs synchronised more in woodland-pasture edges than in woodland interiors, and alternated more and fed more frequently at lower altitude compared to higher altitude nests. Variation in bi-parental coordination behaviours did not have a significant impact on fledging success but more synchronous nests had heavier chicks in woodland habitats. Taken as a whole, our results show that patterns of care are influenced by ecological conditions and that their interplay may change the outcome of sexual conflict.