Behavioural Plasticity Research Papers - Academia.edu (original) (raw)

2025, Functional Ecology

1. A major hypothesis of life-history theory is that conditions of early development affect future survival and reproductive success. Responses to detrimental environments during early ontogeny may involve trade-offs between current and future fitness. Yet, the functional mechanisms involved in such evolutionary trade-offs remain poorly documented. 2. The physiological and behavioural ontogeny of diving abilities was examined in subantarctic fur seal (Arctocephalus tropicalis Gray) pups to assess whether the repeated extreme fasts they naturally endure throughout the period of maternal dependence impacts on their development. 3. The ontogeny of pup body oxygen storage capacity was slow, in particular for the muscle compartment, which shows limited increase in myoglobin content (0AE23-0AE85 g 100 g wet muscle )1 ). As a consequence, by the time of weaning, mass-specific oxygen stores had only reached 76%, 24% and 61% of adult female capacity for blood, muscle and total, respectively. Concomitantly, in marked contrast to other pinniped infants, they spent decreasing amounts of time in water (16-7%) with age and exhibited very little diving experience and skills. 4. Overall, in addition to experiencing the longest fasting durations throughout the maternal dependence period, subantarctic fur seal pups demonstrate the lowest levels of mass-specific total oxygen stores and maximum dive duration of any otariid near the age of weaning reported to date. 5. Furthermore, dives that exceeded the calculated aerobic dive limit occurred with a very low frequency (0AE04%), suggesting that behavioural limitations linked to the necessity to conserve energy to survive repeated fasting, rather than restricted oxygen storage capacity, constrained pup diving behaviour. 6. Hence, these animals appear to trade-off the early development of both their physiological and behavioural diving abilities in favour of body fat accumulation to survive the prolonged fasts they must endure and, potentially, provide a nutritional buffer while they locate appropriate food patches after weaning. While promoting pre-weaning survival, this strategy renders pups more vulnerable to unpredictable changes in environmental conditions and food availability at the transition to independent foraging and, thus, could have negative impact on post-weaning survival.

2025, Animal Behaviour

I examined the potential genetic and environmental determinants of population differences in the foraging behaviour of the colonial spider Parawixia bistriata by using reciprocal transplant and prey manipulation experiments. The population differences noted from a previous study are primarily associated with the degree to which this spider captures prey as a group: P. bistriata show a higher frequency of group capture of prey in dry habitats with lower prey levels than in wet habitats where prey levels are higher. I recorded data on the tendency to capture and feed in groups and the number of individuals feeding on that prey. The transplant experiments revealed population differences in the tendency to capture prey as a group. Individuals from dry habitat showed a greater tendency to participate in group capture and feeding of prey in their native habitat than did individuals from wet habitat or than individuals that were transplanted to dry and wet habitats. In addition, the size of capture and feeding groups showed a significant habitat effect. Individuals from wet habitat did not differ in their tendency to attack prey when transplanted to dry habitat, suggesting that P. bistriata from wet habitat represents an ecotype that lacks behavioural plasticity. In contrast, individuals from dry habitat showed a plastic response. Potential causes of the behavioural plasticity shown by spiders from dry habitat are discussed. Group-foraging behaviour can have a significant effect on the fitness of these spiders, as suggested by their success under low prey conditions.

2025, Animal Behaviour

In fish, the presence of predator cues in the parental or juvenile environment engenders plasticity in the expression of fear-related behaviours. Whether these cues may engender developmental plasticity when they are present in the environment of embryos remains unexplored. Here, we tested in rainbow trout, Oncorhynchus mykiss: (1) whether exposure to alarm cues during embryonic stages engendered developmental plasticity; and (2) whether an abiotic stressor could also orient the behavioural development of fry. We divided fertilized eggs into three groups: a control nonstressed group (Control), a group of embryos exposed to a conspecific alarm pheromone (e.g. predator-related cue stressor, PS), and a group of embryos that were chronically air exposed for 1 min (e.g. abiotic stressor, AS). Stressors were applied once a day, 3 times per week from 19 days postfertilization (dpf) until 52 dpf. Between 57 and 143 dpf, and for each individual, we assessed the propensity to express fear responses in different contexts and learning performances. When exposed to a novel environment or a novel object, PS fish showed significantly less fear-related behaviour, less freezing and higher activity levels than Control fish. PS fish also showed slower acquisition of a learning task than controls. AS fish did not differ from controls in any test situation. Our results show that in ovo exposure to a natural but not an abiotic signal is a prominent inducer of rainbow trout behavioural plasticity across a number of contexts. Our study provides evidence that the expression of neophobia by fish fry may be modulated by the level of risk perceived by embryos in the environment.

2024, HAL (Le Centre pour la Communication Scientifique Directe)

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

2024, Ecology Letters

Theoretical work suggests that both negative frequency-dependent payoffs and state-dependent payoffs can lead to individual variation in behavioural plasticity. We investigated the roles of both frequency-and statedependence on the occurrence of individual variation in behavioural plasticity in a series of experiments where we manipulated perceived predation danger for red knots (Calidris canutus islandica). We found individual variation in plasticity in a trait with negative frequency-dependent payoffs (vigilance), but not in a trait with positive frequency-dependent payoffs (escape flights). Furthermore, there was no correlation between the average level of vigilance under low predation danger and the magnitude of response to increased predation danger, as would be expected under state-dependence. Thus, our results provide support for the hypothesis that negative-frequency dependence favours individual variation in plasticity. However, negative-frequency dependence alone cannot explain why plasticity would be consistent within individuals, and future studies should address the factors that might favour individual consistency.

2024, Diversity and Distributions

AimNo human activity has changed natural habitat availability and ecosystem functioning more than agriculture. As a consequence, species may be forced to use croplands as foraging habitat, resulting in potential conflicts with farmers. To assess the causes and consequences of wildlife–agriculture interactions, we investigated the underlying associations among species traits, climate and landscapes factors that determine parrot species to use croplands, and related them to their conservation status.LocationGlobal.MethodsWe used parrots as a model due to their global distribution, high behavioural plasticity, high proportion of species using croplands (43%) and threatened species (26%). Within the distribution range of the 398 extant parrot species, we calculated annual averages and seasonality of ecosystem productivity, climate conditions and land‐use patterns from satellite data. We then categorized species conservation status using information provided by IUCN.ResultsWe found that ...

2024, Oikos

Alternative reproductive tactics (ARTs) have improved our understanding of the evolution of adaptive variation; for instance, their study has led us to understand that the best phenotype (e.g. large and flashy) for a tactic that uses one mating behavior (e.g. court females) is often not the best phenotype (e.g. small and inconspicuous) for a tactic that uses a different mating behavior (e.g. chase and force‐copulate females). However, genetic correlations of shared traits across ARTs can constrain ARTs from reaching their optimal states, resulting in intralocus tactical conflict (IATC). While constraints on evolution in general have been well‐established and studied, there are some important implications of constraints due to intralocus tactical conflict on ARTs that have not been incorporated into the field of evolutionary ecology. Here we describe how an appreciation of IATC, including how to detect it and when to expect it, can change our perspectives in three areas: 1) adaptive ...

2024, Applied Animal Behaviour Science

Studies on diverse species indicate the existence of individual differences in stress coping strategies labelled as 'proactive' and 'reactive'. Identifying taxonomic distribution of such coping strategies is fundamental to evolutionary models and to management of captive animals. Capuchin monkeys (Sapajus spp) are neotropical primates noted for their cognitive skills and behavioural plasticity. The capuchin clade faces increasing threats from Human Induced Rapid Environment Change, and a growing number of animals are kept in rescue centers and zoos. Based on an ethogram with 28 behavioural categories, we employed Principal Component Analysis to explore differences in behaviour potentially indicative of stress (BPIS) in a sample of 123 captive brown capuchins. We identified five principal components summarising BPIS and labelled as: Restless, Self-narcotizing/fear, Self-protection, Stereotyped, and Help-seek. Multivariate GLM and regression analyses indicated no sex differences. It was not possible to map the five components onto the five personality dimensions recently described for capuchins. However, two of the patterns (Restless and Self-protection) parallel the two coping strategies described in several other species (Proactive and Reactive), and may reflect stress-reactivity that is conserved across species.

2024, Animal Behaviour

Behavioural lateralization, the asymmetric expression of cognitive functions, is reported to enhance key fitness-relevant traits such as group coordination, multitasking and predator escape. Therefore, studies reporting negative effects on lateralization in fish due to environmental stressors such as ocean acidification, hypoxia and pollutants are worrisome. However, such studies tend to use a detour test and focus on population level measures, without validating whether lateralization is consistent within individuals across time. We conducted a multispecies, international assessment of the repeatability (R) of lateralization in four previously studied fish species using a detour test (T-maze), a common method for testing lateralization. We also reanalysed a published data set on a fifth species using new statistical methods. We expected the three shoaling species to exhibit greater within-individual consistency in lateralization than their nonshoaling counterparts given previous reports of stronger lateralization in group-living fishes. Absolute and relative lateralization scores were highly nonrepeatable in all five species (0.01<R<0.08), irrespective of their shoaling status. We carefully reviewed 31 published studies in which the detour test was employed to examine lateralization in fish and identified statistical issues in all of them. We develop and propose new statistical analyses to test for population and individual level lateralization. The commonly used detour test does not appear to be appropriate for quantifying behavioural lateralization in fishes, calling into question functional inferences drawn by many published studies, including our own. Potential fitness benefits of lateralization and anthropogenic effects on lateralization as a proxy for adaptive brain functioning need to be assessed with alternative paradigms.

2024, Movement Ecology

Background Habitat loss can force animals to relocate to new areas, where they would need to adjust to an unfamiliar resource landscape and find new breeding sites. Relocation may be costly and could compromise reproduction. Methods Here, we explored how the Lesser black-backed gull (Larus fuscus), a colonial breeding seabird species with a wide ecological niche, responds to the loss of its breeding habitat. We investigated how individuals adjusted their foraging behaviour after relocating to another colony due to breeding site destruction, and whether there were any reproductive consequences in the first years after relocation. To this end, we compared offspring growth between resident individuals and individuals that recently relocated to the same colony due to breeding habitat loss. Using GPS-tracking, we further investigated the foraging behaviour of resident individuals in both colonies, as well as that of relocated individuals, as enhanced foraging effort could represent a pot...

2024, Diversity and Distributions

2024, Proceedings of the Royal Society B: Biological Sciences

Chemical contaminants (e.g. metals, pesticides, pharmaceuticals) are changing ecosystems via effects on wildlife. Indeed, recent work explicitly performed under environmentally realistic conditions reveals that chemical contaminants can have both direct and indirect effects at multiple levels of organization by influencing animal behaviour. Altered behaviour reflects multiple physiological changes and links individual- to population-level processes, thereby representing a sensitive tool for holistically assessing impacts of environmentally relevant contaminant concentrations. Here, we show that even if direct effects of contaminants on behavioural responses are reasonably well documented, there are significant knowledge gaps in understanding both the plasticity (i.e. individual variation) and evolution of contaminant-induced behavioural changes. We explore implications of multi-level processes by developing a conceptual framework that integrates direct and indirect effects on behavi...

2024, Applied Animal Behaviour Science

2024, Proceedings of The Royal Society B: Biological Sciences

Biodiversity is threatened by the growth of urban areas. However, it is still poorly understood how animals can cope with and adapt to these rapid and dramatic transformations of natural environments. The COVID-19 pandemic provides us with a unique opportunity to unveil the mechanisms involved in this process. Lockdown measures imposed in most countries are causing an unprecedented reduction of human activities, giving us an experimental setting to assess the effects of our lifestyle on biodiversity. We studied the birds' response to the population lockdown by using more than 126 000 bird records collected by a citizen science project in northeastern Spain. We compared the occurrence and detectability of birds during the spring 2020 lockdown with baseline data from previous years in the same urban areas and dates. We found that birds did not increase their probability of occurrence in urban areas during the lockdown, refuting the hypothesis that nature has recovered its space in human-emptied urban areas. However, we found an increase in bird detectability, especially during early morning, suggesting a rapid change in the birds' daily routines in response to quieter and less crowded cities. Therefore, urban birds show high behavioural plasticity to rapidly adjust to novel environmental conditions, such as those imposed by the COVID-19.

2024, Proceedings of the Royal Society B: Biological Sciences

Little is known about the factors causing variation in behavioural plasticity and the interplay between personality and plasticity. Habituation to predators is a special case of behavioural plasticity. We investigated the direct and indirect effects of boldness, exploration and sociability traits on the habituation ability of Iberian wall lizards, considering exposure and sex effects. Individual boldness was consistent across several non-habituation contexts, but it did not significantly affect habituation. Exploration had a strong direct effect on habituation, with more exploratory individuals being able to habituate faster than less exploratory ones, probably because of their ability to assess risk better. Individual variation in habituation was also affected by sociability, but this was an indirect effect mediated by exposure to the predator. Less social individuals avoided refuges with conspecific cues, increasing exposure to the predator and eventually habituation. Finally, the...

2023, Oikos

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version... more

2023, Royal Society Open Science

Humpback whales (Megaptera novaeangliae) have exceptionally long pectorals (i.e. flippers) that aid in shallow water navigation, rapid acceleration and increased manoeuvrability. The use of pectorals to herd or manipulate prey has been hypothesized since the 1930s. We combined new technology and a unique viewing platform to document the additional use of pectorals to aggregate prey during foraging events. Here, we provide a description of 'pectoral herding' and explore the conditions that may promote this innovative foraging behaviour. Specifically, we analysed aerial videos and photographic sequences to assess the function of pectorals during feeding events near salmon hatchery release sites in Southeast Alaska (2016-2018). We observed the use of solo bubble-nets to initially corral prey, followed by calculated movements to establish a secondary boundary with the pectorals-further condensing prey and increasing foraging efficiency. We found three ways in which humpback whales use pectorals to herd prey: (i) create a physical barrier to prevent evasion, (ii) cause water motion to guide prey towards the mouth, and (iii) position the ventral side to reflect light and alter prey movement. Our findings suggest that behavioural plasticity may aid foraging in changing environments and shifts in prey availability. Further study would clarify if 'pectoral herding' is used as a principal foraging tool by the broader humpback whale population and the conditions that promote its use. 1. Background Large body sizes of baleen whales generate high metabolic demands that require the consumption of sizable, dense patches

2023, Oecologia

In the presence of a predator, foraging is a dangerous task. Social individuals can respond to risk by forming groups, benefiting from enhanced collective anti-predator behavior but suffering from increased conspicuousness to predators. Within groups, individuals exhibit variable foraging behavior. One important factor influencing risky foraging behaviour is current energetic state, and individuals must trade off food and safety by deciding when to leave a protected refuge in order to find food. We generated mixed groups of goldfish (Carassius auratus) containing equal numbers of underfed and well-fed individuals and examined individual refuge use and willingness to take risks venturing into risky foraging areas in the presence of an avian predator (little egret-Egretta garzetta). Underfed fish exhibited higher levels of risky behaviour by participating in more foraging outings and emerging from the refuge in frontal group positions, compared with well-fed individuals. As expected, underfed fish benefitted by consuming more food, but surprisingly did not experience higher rates of mortality. This may be due to the fact that the egret predator rarely captured the first fish to emerge from the refuge, preferentially attacked groups of three or more fish, and often captured fish in the chaotic period following a failed initial strike. We demonstrate how differences in energetic condition can influence risk-taking behaviours among social individuals that subsequently influence relative levels of foraging success and group fission-fusion dynamics. Moreover, our results illustrate the risk associated with foraging in larger groups.

2023, Proceedings of the Royal Society B: Biological Sciences

2023, Marine Ecology Progress Series

Climate models predict a multi-degree warming of the North Atlantic in the 21st century. A research priority is to understand the effect of such changes upon marine organisms. With 40 to 80 million individuals, planktivorous little auks Alle alle are an essential component of pelagic food webs in this region that is potentially highly susceptible to climatic effects. Using an integrative study of their behaviour, physiology and fitness at 3 study sites, we evaluated the effect of ocean warming on little auks across the Greenland Sea in 2005 to 2007. Contrary to our hypothesis, the birds responded to a wide range of sea surface temperatures via plasticity of their foraging behaviour, allowing them to maintain their fitness levels. Predicted effects of climate change are significantly attenuated by such plasticity, confounding attempts to forecast future effects of climate change using envelope models. KEY WORDS: Behavioural plasticity • Envelope models • Global warming • North Atlantic • Pelagic food web • Zooplankton Resale or republication not permitted without written consent of the publisher Contribution to the Theme Section 'Seabirds and climate change'

2023, Animal Behaviour

Boldness is a personality trait that defines how individuals respond to risky situations and has clear fitness consequences. Since the adaptive value of boldness is context dependent, the benefit of a distinct personality is less clear when the environment is unpredictable. An ability to modulate behaviour can be beneficial, although as behavioural plasticity itself may be costly this depends on the levels of environmental stability. Both boldness and its plasticity are linked with physiological stress coping mechanisms, whereby animals with reduced glucocorticoid responses to stress are bolder and less flexible in behaviour. We investigated the behavioural changes made by bold and shy rainbow trout, and the magnitude of those changes, in response to predation risk and exposure to two environmental challenges. Behavioural and physiological responses under biotic (either no, predictable or unpredictable predation risk) and abiotic (temperature increase or hypoxia) factors were measured. Boldness was determined using a standard novel object paradigm. In general, after exposure to the treatments, fish exhibited less extreme bold or shy behaviour; the greatest change was observed in fish exposed to hypoxia, or those exposed to high risk particularly in shy fish held at a lower temperature. Higher risk also resulted in increased stress, suggesting that extreme bold or shy behaviour might have been maladaptive under a potential predator threat. These results represent novel evidence that boldness is flexible depending upon particular environmental challenges, with important implications for populations facing environmental extremes caused by anthropogenic activity and climate change. Individuals exhibit consistent differences in response to an environmental challenge which are expressed across a range of contexts and situations. Such discrete sets of behaviour are termed behavioural syndromes or animal personalities (Dingemanse & Réale 2005), and each individual within a species can be described as having a particular behavioural type (Sih et al. 2004). One such personality is boldness, which defines an individual's response to novelty and its propensity for taking risks: bold animals are often (although not always; reviewed in Conrad et al. 2011) more aggressive, more active and more likely

2023, Movement Ecology

Background Consistent inter-individual differences in behavioural phenotypes may entail differences in energy efficiency and expenditure, with different fitness payoffs. In colonial-breeding species, inter-individual differences in foraging behaviour may evolve to reduce resource use overlap among conspecifics exploiting shared foraging areas. Furthermore, individual differences in foraging behaviour may covary with individual characteristics, such as sex or physiological conditions. Methods We investigated individual differences in foraging tactics of a colonial raptor, the lesser kestrel (Falco naumanni). We tracked foraging trips of breeding individuals using miniaturized biologgers. We classified behaviours from GPS data and identified tactics at the foraging trip level by cluster analysis. We then estimated energy expenditure associated to each tactic from tri-axial accelerometer data. Results We obtained 489 foraging trips by 36 individuals. Two clusters of trips were identifi...

2023, Applied Animal Behaviour Science

Recent years have seen a growth of interest in the consistent differences in individual behaviour over time and contexts constituting so-called "individual coping styles". An understanding of this inter-individual variation is essential to improve our knowledge of the adaptive value of behaviour. Coping styles may have implications in diverse fields, so the development of appropriate screening methods for each species appears to be the most effective way to extend our knowledge and to incorporate behavioural responses into selection-based breeding programmes, to improve the domestication and welfare of farmed fish. We tested 30 juvenile seabass (Dicentrarchus labrax) at least twice in individual-based tests (feeding recovery in isolation, aggressiveness, exploration in a T-maze and net restraint) and group-based tests (risk-taking and hypoxia sorting), to assess coping style consistency in the short and long term and between tests. The results of individual-based tests were inconsistent over time and between tests in our setup: the time between repeat tests, learning and species-specific behavioural responses appeared to have a major impact. By contrast, the results of group-based tests, such as risk-taking and hypoxia sorting, appeared to be consistent (both in the short and long term). These tests therefore appeared to be the most relevant for the characterisation of coping style in European seabass. Furthermore, the results of these tests were also predictive of cortisol stress response. These tests are simple to perform and can be used to screen large numbers of fish, the first step in selection programmes including behavioural profiles Highlights ► We characterized coping styles in European seabass.► We showed evidence for behavioural consistency in group based tests.► Results may also be accounted for by species specificity in behavioural responses.

2023, Behavioral Ecology

Behavioral variation has been documented both between and within populations in a variety of traits. Many of these behavioral traits are phenotypically plastic and are conditional on the early environment an animal experiences, yet despite this the role of the environment in generating variation in boldness is not well understood. Here we investigate the importance of early and recent experience of temporal unpredictability in food supply on the behavior of a species of freshwater fish, the Trinidadian guppy Poecilia reticulata. We predict that individuals that experience temporally unpredictable food supplies will engage in more risky behavior than those experiencing a predictable food supply and find evidence to support this. Fish with early experience of unpredictable environments are generally bolder and more exploratory than fish reared in predictable environments, exploring a significantly greater proportion of a novel maze and spending less time in a refuge during the trial. Individuals with early experience of unpredictability also spent significantly less time associating with conspecifics in a shoaling tendency assay, again suggesting that they are bolder than guppies reared in predictable conditions. These findings suggest that early experience is important in shaping exploratory and shoaling behavior in this species and that unpredictability in early life can influence boldness in guppies.

2023, PLOS Computational Biology

Locusts are short horned grasshoppers that exhibit two behaviour types depending on their local population density. These are: solitarious, where they will actively avoid other locusts, and gregarious where they will seek them out. It is in this gregarious state that locusts can form massive and destructive flying swarms or plagues. However, these swarms are usually preceded by the aggregation of juvenile wingless locust nymphs. In this paper we attempt to understand how the distribution of food resources affect the group formation process. We do this by introducing a multi-population partial differential equation model that includes non-local locust interactions, local locust and food interactions, and gregarisation. Our results suggest that, food acts to increase the maximum density of locust groups, lowers the percentage of the population that needs to be gregarious for group formation, and decreases both the required density of locusts and time for group formation around an opti...

2023, Global change biology

Arctic climate change has profound impacts on the cryosphere, notably via shrinking sea-ice cover and retreating glaciers, and it is essential to evaluate and forecast the ecological consequences of such changes. We studied zooplankton-feeding little auks (Alle alle), a key sentinel species of the Arctic, at their northernmost breeding site in Franz-Josef Land (80°N), Russian Arctic. We tested the hypothesis that little auks still benefit from pristine arctic environmental conditions in this remote area. To this end, we analysed remote sensing data on sea-ice and coastal glacier dynamics collected in our study area across 1979-2013. Further, we recorded little auk foraging behaviour using miniature electronic tags attached to the birds in the summer of 2013, and compared it with similar data collected at three localities across the Atlantic Arctic. We also compared current and historical data on Franz-Josef Land little auk diet, morphometrics and chick growth curves. Our analyses re...

2022, Journal of Animal Ecology

1. Once established in new areas, introduced species may exhibit changes in their biology due to phenotypic plasticity, novel selection pressures and genetic drift. Moreover, the introduction process itself has been hypothesised to act as a selective filter for traits that promote invasiveness. 2. We tested the hypothesis that behaviours thought to promote invasiveness-such as increased foraging activity and aggression-are selected for during invasion by comparing traits among native and introduced populations of the widespread Argentine ant (Linepithema humile). 3. We studied Argentine ant populations in the native range in Argentina and in three invaded regions along an introduction pathway: California, Australia and New Zealand. In each region, we set up 32 experimental colonies to measure foraging activity and interspecific aggression in a subset of the study regions. These colonies were subject to experimental manipulation of carbohydrate availability and octopamine, a biogenic amine known to modulate behaviour in insects, to measure variation in behavioural plasticity. 4. We found variation in foraging activity among populations, but this variation was not consistent with selection on behaviour in relation to the invasion process. We found that colonies with limited access to carbohydrates exhibited unchanged exploratory behaviour, but higher exploitation activity and lower aggression. Colonies given octopamine consistently increased foraging behaviour (both exploration and exploitation), as well as aggression when also sugar-deprived. There was no difference in the degree of behavioural response to our experimental treatments along the introduction pathway. 5. We did not find support for selection of behavioural traits associated with invasiveness along the Argentine ant's introduction pathway or clear evidence for an association between the introduction process and variation in behavioural plasticity. These results indicate that mechanisms promote behavioural variation in a similar fashion both in native and introduced ranges. Our results challenge the

2022, Functional Ecology

1. A major hypothesis of life-history theory is that conditions of early development affect future survival and reproductive success. Responses to detrimental environments during early ontogeny may involve trade-offs between current and future fitness. Yet, the functional mechanisms involved in such evolutionary trade-offs remain poorly documented. 2. The physiological and behavioural ontogeny of diving abilities was examined in subantarctic fur seal (Arctocephalus tropicalis Gray) pups to assess whether the repeated extreme fasts they naturally endure throughout the period of maternal dependence impacts on their development. 3. The ontogeny of pup body oxygen storage capacity was slow, in particular for the muscle compartment, which shows limited increase in myoglobin content (0AE23-0AE85 g 100 g wet muscle)1). As a consequence, by the time of weaning, mass-specific oxygen stores had only reached 76%, 24% and 61% of adult female capacity for blood, muscle and total, respectively. Concomitantly, in marked contrast to other pinniped infants, they spent decreasing amounts of time in water (16-7%) with age and exhibited very little diving experience and skills. 4. Overall, in addition to experiencing the longest fasting durations throughout the maternal dependence period, subantarctic fur seal pups demonstrate the lowest levels of mass-specific total oxygen stores and maximum dive duration of any otariid near the age of weaning reported to date. 5. Furthermore, dives that exceeded the calculated aerobic dive limit occurred with a very low frequency (0AE04%), suggesting that behavioural limitations linked to the necessity to conserve energy to survive repeated fasting, rather than restricted oxygen storage capacity, constrained pup diving behaviour. 6. Hence, these animals appear to trade-off the early development of both their physiological and behavioural diving abilities in favour of body fat accumulation to survive the prolonged fasts they must endure and, potentially, provide a nutritional buffer while they locate appropriate food patches after weaning. While promoting pre-weaning survival, this strategy renders pups more vulnerable to unpredictable changes in environmental conditions and food availability at the transition to independent foraging and, thus, could have negative impact on post-weaning survival.

2022, Animal Behaviour

Social insect colonies are self-organized systems that respond to changes in environmental conditions by altering the relative proportions of certain castes or individuals engaged in specific tasks. While termites are known to regulate the ratio of morphologically specialized soldiers in response to the proportion of nestmate castes, soldier-differentiation process requires a relatively long time to be accomplished. Consequently, other plastic and flexible mechanisms are considered to be employed as one of the various defensive strategies in termites. In this study, the defensive behaviours of soldiers, pseudergates (workers) and reproductives of the damp-wood termite Hodotermopsis sjostedti were quantified. When individuals of the caste were exposed to an intruder, soldiers exhibited the most vigorous defensive behaviour, followed by pseudergates and then reproductives. While the aggression levels of soldiers and reproductives were independent of the accompanying castes, pseudergate aggression was more plastic and depended on the other castes present. When paired with reproductives, pseudergates exhibited high levels of aggression toward enemies. However, pseudergate aggression levels remained low when they were paired with soldiers, suggesting that pseudergates moderated their defensive behaviour depending on social context. Plasticity with respect to social behaviours may facilitate rapid and 3 flexible responses required for colony defence.

2022, Marine Ecology Progress Series

2022, Behavioural Brain Research

h i g h l i g h t s • Zebrafish were exposed to different fighting experiences: winning, losing and mirror-fighting. • Winners show higher serotonergic and dopaminergic activity in the telencephalon. • Losers show higher serotonergic in the optic tectum. • No significant changes in monoamine activity were observed in mirror fighters. • Monoamines are differentially regulated by social interactions in different brain regions.

2022, Ecology Letters

2022, Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques

The phenomenon of the sputtering of solids under bombardment with molecular ions is considered within the framework of synergetics. The complete sputtering process is divided into three stages with the help of the concept of three successive regimes: the implementation of a dynamic system, the appearance of a statistical system, and the achievement of a completely statistical system. The manifestation of the basic mechanisms is revealed: elastic cascades and mass transfer under the action of shock waves.

2022, BMC evolutionary biology

Black sparrowhawks (Accipiter melanoleucus) recently colonised the Cape Peninsula, South Africa, where the species faces competition for their nest sites from Egyptian geese (Alopochen aegyptiaca) which frequently usurp black sparrowhawk nests. In this paper, we test the hypothesis that multiple nest building by black sparrowhawks is a strategy to cope with this competitor, based on a 14-year long term data set. Two main results support the hypothesis: first, the numbers of intact nests per breeding season in black sparrowhawk territories increased as levels of geese interactions increased, specifically when usurpation occurred. Usurpation occurred significantly more often at nests later in the season, and may provide a further explanation for the advancement of the black sparrowhawk breeding season towards earlier breeding attempts which results in an overall extension of the breeding period (over 9 months) that has been found in our study population. Second, nest usurpation had a ...

2022, Oecologia

2022, Frontiers in zoology

The expression of animal personality is indicated by patterns of consistency in individual behaviour. Often, the differences exhibited between individuals are consistent across situations. However, between some situations, this can be biased by variable levels of individual plasticity. The interaction between individual plasticity and animal personality can be illustrated by examining situation-sensitive personality traits such as boldness (i.e. risk-taking and exploration tendency). For the weakly electric fish Gnathonemus petersii, light condition is a major factor influencing behaviour. Adapted to navigate in low-light conditions, this species chooses to be more active in dark environments where risk from visual predators is lower. However, G. petersii also exhibit individual differences in their degree of behavioural change from light to dark. The present study, therefore, aims to examine if an increase of motivation to explore in the safety of the dark, not only affects mean le...

2022, Behavioral Ecology and Sociobiology

Consistent differences in human behaviour are often explained with reference to personality traits. Recent evidence suggests that similar traits are widespread across the entire animal kingdom and that they may have substantial fitness consequences. One of the major components of personality is the shyness-boldness continuum. Little is known about the relative contributions of genes and the environment in the development of boldness in wild animal populations. Here, we bred wild-caught fish (Brachyraphis episcopi) collected from regions of highand low-predation pressure, reared their offspring in the laboratory under varying conditions and tested boldness utilising an open-field paradigm. First-generation laboratory-reared fish showed similar behaviour to their wild parents suggesting that boldness has a heritable component. In addition, repeated chasing with a net increased boldness in both high-and low-predation offspring, showing that boldness is also heavily influenced by life experiences. Differences between males and females were also sustained in the laboratory-reared generation indicating that sex differences in boldness are also heritable. We discuss these results with reference to the potential underlying genetic and hormonal mechanisms as well as the environmental influences that may be responsible for expression of boldness in wild animals.

2022

Consistent individual differences in boldness have been identified in many species and can have important effects on fitness. In most animals, juveniles face different costs and benefits of risk-taking behavior than do adults. Furthermore, profound changes in hormones, mor-phology and environment often occur when juveniles become adults. Therefore, the boldness of individuals might change with ontogeny. In field crickets, adult males call to attract sexually receptive females, and male calling increases predation risk. We measured the repeatability of boldness (latency to emerge from a safe refuge) in both male and female crickets. Each cricket was tested once as a small nymph and once as an adult. We found that boldness was repeatable across metamorphosis in females, but not in males. Males became less bold with maturation, a result that we predicted because of the risk associated with calling for mates. We also found that in general, nymphs were bolder than adults and that individ...

2022, Behavioral Ecology and Sociobiology

Boldness, the tendency to be explorative, risk prone and proactive, often varies consistently between individuals. An individual's position on the boldness-shyness continuum has many implications. Bold individuals may outperform shyer conspecifics during foraging as they cover more ground, accumulate information more rapidly and make more frequent food discoveries. Individual variation in boldness may also affect behavioural plasticity across environmental contexts, as the time to process new information, the ability to locate and memorise resources and the time and ability to apply prior information in a novel context all differ between individuals. The primary aim of the current study was to examine plasticity in, and covariation between, boldness, foraging speed and foraging accuracy across social foraging contexts. We showed that the stickleback that were shyest when foraging alone became relatively boldest when foraging in a social context and also delayed their entry to a known food patch the most in the presence of conspecifics. These results support the assertion that shyer foragers are more reactive to social cues and add to current knowledge of how an individual's position on the boldness-shyness continuum may correlate to foraging task performance and behavioural plasticity. We conclude that the correlation between boldness and behavioural plasticity may have broad relevance as the ability to adjust or retain behaviours in changing social environments could often have consequences for fitness. Significance statement Animal personality may affect how much individuals change their behaviour to suit different environments. We studied the link between threespine stickleback personality (boldness or shyness), foraging performance and change in foraging performance when either alone or in the presence of other stickleback. We found that shyer threespine stickleback were more reactive to the presence of other fish when foraging. When observed or joined by other fish, shy stickleback started exploring earlier, but entered a known food patch later, than when alone. Bolder stickleback changed their foraging behaviour much less in the presence of other fish. Our results suggest that how bold or shy individuals are may have important consequences on how well they adjust their foraging behaviour to environmental change.

2022, Behavioral Ecology

Variable levels of predation pressure are known to have significant impacts on the evolutionary ecology of different populations and can affect life-history traits, behavior, and morphology. To date, no studies have directly investigated the impact of predation pressure on cognitive ability. Here we use a system of replicate rivers, each with sites of high-and low-predation pressure, to investigate how this ecological variable affects learning ability in a tropical poeciliid, Brachyraphis episcopi. We used a spatial task to assess the cognitive ...

2021, Ecology and Evolution

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

2021, Behavioral Ecology

There have been many investigations into consistent, individual differences in behavior (animal personalities), but rather less attention has been given to the possibility that individuals might differ consistently in their "cognitive style," which refers to the way information is acquired, processed, stored, or acted on. Both personality and cognition have important fitness consequences, and it has been proposed that variation in cognition could be functionally related to variation in personality. Here, we test this hypothesis using three-spined sticklebacks (Gasterosteus aculeatus) as a model and adopt a classic T-maze with food reward experimental paradigm. We first confirmed that fish choose the correct arm of the maze significantly more than would be expected by chance and that this improves with trial number. We then explored predictors of individual differences in the speed (time to making a decision) and accuracy (whether the first decision is correct) in decision making. We find bolder behavioral types (who tend to be male) arrive at the correct decision sooner than their shyer conspecifics. However, boldness was not related to decision accuracy. Moreover, we did not find any significant difference in fish's improvement in decision accuracy over successive trials according to boldness or sex. This suggests that although bolder fish may acquire information more quickly because they make decisions faster, they do not differ from shyer conspecifics in their decisionmaking accuracy. The absence of such a trade-off might offer a functional explanation for why, in stickleback fish and many other species, bolder individuals tend to initiate movement and shyer individuals to follow-bold leaders may result in faster group decisions without compromising accuracy.

2021, Frontiers in zoology

2021, Behavioral Ecology and Sociobiology

Consistent individual differences in boldness have been identified in many species and can have important effects on fitness. In most animals, juveniles face different costs and benefits of risk-taking behavior than do adults. Furthermore, profound changes in hormones, morphology and environment often occur when juveniles become adults. Therefore, the boldness of individuals might change with ontogeny. In field crickets, adult males call to attract sexually receptive females, and male calling increases predation risk. We measured the repeatability of boldness (latency to emerge from a safe refuge) in both male and female crickets. Each cricket was tested once as a small nymph and once as an adult. We found that boldness was repeatable across metamorphosis in females, but not in males. Males became less bold with maturation, a result that we predicted because of the risk associated with calling for mates. We also found that in general, nymphs were bolder than adults and that individuals spent more time immobile in response to a predator cue when they were nymphs, versus when they were adults.

2021, Applied Animal Behaviour Science

Biological variability is no longer considered as statistical noise, but rather as an adaptive benefit. This variability comes from consistent differences in behavioral and physiological responses among individuals to a changing/challenging environment, named "coping style", "temperament" or "personality". Many studies have described how to characterize personality traits and how to assess their consistency over time and between different contexts; however, little is known about the environmental factors shaping personality development. Because contrasting personalities are maintained with evolution, this lead to the widespread assumption that genes play a predominant role in personality. In many cases, personality traits are however also likely to be determined by individual experience, which is probably at least as important as genetics in shaping personality. The aim of this study was to assess how environmental variability (herein food predictability) impacts behavioral responses, particularly the shyness-boldness axis, one of the most widely shared animal personality trait. Here, we reared juvenile seabass (95 days old) from two divergent strains selected for feed deprivation tolerance under standard conditions for 40 days. Thereafter, we submitted them to two feeding treatments (Predictable vs Unpredictable) starting at 135 dph and lasting 60 days. Seabass reared under a predictable food supply (PFS) grew faster and were shyer than fish reared under an unpredictable food supply (UFS) (i.e. they took more time to exit the refuge zone of a Z-maze; UFS: 132.47 ± 34.63 s; PFS: 336.79 ± 56.97 s) but their exploration tendency was similar. We also examined the behavioral responses of these fish facing a hypoxic challenge. Hypoxia tolerance results were consistent before and after the two feeding treatments. Our findings show the importance of early environmental experience as a driving force shaping boldness. In addition, we provide further evidence that predictable feeding time should be respected in studies assessing essential functions such as growth and behavior. Although personality traits are partially heritable, this study demonstrates the important influence of environmental conditions and life history on behavior Highlights ► Early and recent experience is an important driving force shaping boldness in European seabass. ► Experiencing a predictable food supply induced faster growth and fish became shyer than fish reared under an unpredictable food supply. ► Predictable feeding time should be respected when assessing essential physiological functions such as growth and behavior.

2021, Behavioral Ecology

2021, Biological Journal of the Linnean Society

In this study we investigated the environmental regulation of daily reproductive activity of guppies (Poecilia reticulata). We observed male guppy reproductive behaviour for 17 days over three time periods (dawn, noon, and dusk) while recording natural variation in water temperature and light level. Water temperatures recorded during the experiments were highly variable (up to 7°C per day), and there was a recurring pattern in daily variation for both light and temperature. Levels of activity were highest at dawn and similarly low during noon and dusk, but reproductive behaviour was recorded throughout the day. Mixed-effects models indicate that light and temperature affect reproductive behaviour differently at different times of the day, and can also have opposing effects. We suggest that the environmental heterogeneity of streams in Trinidad has led to a broad thermal tolerance, and has contributed to the high level of phenotypic plasticity in the guppy and its success as an invasive species. Furthermore, our results show that daily variation in temperature and its interaction with light should be considered in future studies of guppy reproductive behaviour.