42 research outputs found
Contextual variation in the alarm-call responses of dwarf mongooses, <i>Helogale parvula</i>
No full textAlarm calling is a widespread anti-predator behaviour, but it is not always a reliable indication of real danger. Individuals must decide when to respond to alarm calls as a function of the relative costs and benefits, but experiments investigating contextual influences are rare. We use playback experiments in conjunction with supplementary feeding and the presentation of direct predator cues to examine variation in receiver responses to alarm calls in a habituated population of wild dwarf mongooses (Helogale parvula). First, we investigated whether individuals adjust their response to alarm calls depending on their own satiation level and spatial position of the caller. Individuals were more likely to respond to alarm calls when they had received supplementary food, and hence could prioritise minimisation of predation risk over starvation. There was also increased responsiveness to alarm calls given by individuals in elevated spatial positions compared to those on the ground; sentinels (raised guards) are more likely to detect potential predators than foragers, and alarm calls from elevated positions are thus likely to be perceived as more reliable. When individuals did respond, they were more likely to flee following an alarm call given from ground level; foragers are likely to detect predators in closer proximity than sentinels, requiring a more urgent escape response. Second, we examined how individuals combine social information provided by alarm calls with personal information relating to predator presence. Receiver responses to terrestrial and aerial alarm calls did not differ when they followed interaction with an olfactory predator cue compared to an olfactory control cue. Following interaction with a terrestrial predator cue, however, latency to non-vigilance was significantly longer after hearing an aerial alarm call than a terrestrial alarm call, potentially as a result of social information novelty. Our results provide experimental evidence that receivers respond flexibly to alarm calls depending on receiver, signaller and external factors
The modularity of a social group does not affect the transmission speed of a novel, socially learned behaviour, or the formation of local variants
No full textData set used within the Article "The modularity of a social group does not affect the transmission speed of a novel, socially learned behaviour, or the formation of local variants."
The structure of a group is critical in determining how a socially learnt behaviour will spread. Predictions from theoretical models indicate that specific parameters of social structure differentially influence social transmission. Modularity describes how the structure of a group or network is divided into distinct subgroups or clusters. Theoretical modelling indicates that the modularity of a network will predict the rate of behavioural spread within a group, with higher modularity slowing the rate of spread and facilitating the establishment of local behavioural variants which can prelude local cultures. Despite prolific modelling approaches, empirical tests via manipulations of group structure remain scarce.
We experimentally manipulated the modularity of populations of domestic fowl chicks, Gallus gallus domesticus, to affect the transmission of a novel foraging behaviour. We compared the spread of behaviour in populations with networks of high or low modularity against a control population where social transmission was prevented.
We found the foraging behaviour to spread socially between individuals when the social transmission was permitted; however, modularity did not increase the speed of behavioural spread nor lead to the initial establishments of shared behavioural variants. This result suggests that factors in the social transmission process additional to the network structure may influence behavioural spread.
This dataset includes:
The manipulated social networks of our 6 populations of domestic chicks (2 of high modularity, 2 of low modularity and 2 asocial control populations where social transmission was prevented).
The order in which chicks learnt the solving behaviour alongside information on individual level variables.
The solving techniques used by chicks in all their solves throughout the experiment.
The R code use to perform the analyses (Coxph analysis, OADA, testing for assortment)Funding provided by: ERCCrossref Funder Registry ID: http://dx.doi.org/NoneAward Number: 616474File
Title
Short Description
ManuscriptModularity.R
R code for all analysis
R code for all analysis conducted within the manuscript
cumulativeLearningPotential
NetworksChicksModularity
Combined.RData
Dynamic OADA networks
R data to load (containing the dynamic OADA networks used in the analysis)
ChicksModularity Number RB doors.txt
Data on chicks solving techniques
This data describes every individual's solving techniques performed across the experiment.
LowCombinedNetsNAs.txt
Social networks of Low modularity
Social networks for populations of the low modularity condition
HighCombinedNetsNAs.txt
Social networks of High modularity
Social networks for populations of the high modularity condition
Chicks 4&5&7 survival D rem.txt
Data for Survival (coxph) analysis
This data describes at which point each individual first acquired the novel solving behaviour, used for the coxph model. (Initial demonstrators removed
'How warped the mirrors': postmodernism and historiography
No full textPostmodernism, though it may be described in many ways, may be thought essentially to be captured by Lyotard's phrase, 'incredulity towards metanarratives'. The first chapter of my thesis attempts to define both 'postmodernism' and 'historiography', and then surveys historiographical discourse today. Because it is often ancient history that most frequently may be open to radically differing interpretations, I take in chapter two a 'generative' example, namely the speech compositions of Thucydides. This example I consider as 'generative' in the sense that it opens up questions, not only about the History of Thucydides itself and about how Thucydides is conceived in the ancient historiographical tradition, but also about what it means for an historian to disclose the 'truth' of an historical situation. My third chapter takes up the suggestion by Keith Jenkins that postmodern philosophy, particularly the conception of 'truth' and 'knowledge' proffered by Rorty, is a good way for history to acclimatise itself in the postmodern era. I survey Jenkins' proposals, and then discuss a work Jenkins largely ignores, i.e. Rorty's Philosophy and the Mirror of Nature. I demonstrate not just the familiar point that Rorty attempts to overturn 'foundationalist epistemology', and proposes 'new vocabularies' that involve 'hermeneutics' which set up I discourse as 'conversation'. This overturning involves for Rorty an assertion of 'unarbitrability', i.e. that it is impossible to argue that one view is better or more true than another. Thus Jenkins wishes to enter a world of a plurality of interpretations. In chapter four, however, I draw upon the work of Charles Taylor who argues for the necessity of 'arbitrage' in human discourse, whilst still wishing to overturn epistemological foundationalism. I therefore wish to advocate in my fifth chapter a 'third way', drawing on Taylor's theory of interpretation that requires neither a correspondence theory of truth, nor unarbitrability. Throughout the chapter I demonstrate how my conclusions regarding Thucydidean speeches and my discussion of postmodern philosophy may serve as a way of thinking about the task of historians, and hot just ancient historians. I conclude with some theological reflections on the arguments offered
Dynamic eye colour as an honest signal of aggression
No full textThis is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordAnimal eyes are some of the most widely recognisable structures in nature. Due to their salience
to predators and prey, most research has focussed on how animals hide or camouflage their
eyes [1]. However, across all vertebrate Classes many species actually express brightly
coloured or conspicuous eyes, suggesting they may have also evolved a signalling function. Nevertheless, perhaps due to the difficulty with experimentally manipulating eye appearance, very few species beyond humans [2] have been experimentally shown to use eyes as signals [3]. Using staged behavioural trials we show that Trinidadian guppies (Poecilia reticulata), which can rapidly change their iris colour, predominantly express conspicuous eye colouration when performing aggressive behaviours towards smaller conspecifics. We then show, using a
novel visually-realistic robotic system to create a mismatch between signal and relative competitive ability, that eye colour is used to honestly signal aggressive motivation. Specifically, robotic ‘cheats’, i.e. smaller and thus less-competitive robotic fish that displayed aggressive eye colouration when defending a food patch, attracted greater food competition from larger real fish. Our study suggests that eye colour may be an under-appreciated aspect of signalling in animals, shows the utility of our new biomimetic robotic system for investigations in animal behaviour, and provides rare experimental evidence that socially-mediated costs towards low-quality individuals may maintain the honesty of dynamic colour signals.This work was supported by a research grant from the Leverhulme Trust (RPG-2015-047)
awarded to D.P.C. and S.K.D. D.P.C. and S.K.D. also acknowledge funding from the Danish
Council for Independent Research (DFF – 1323-00105). We are very grateful to Rajendra
Mahabir for assistance in the field, to Fiona Moultrie, Joah Madden, Sam Ellis, Ashley Ward,
and John Endler for valuable discussion, and to Tom Houslay for advice on the R code to
generate the plots
Data from: Heritability and correlations among learning and inhibitory control traits
No full textTo understand the evolution of cognitive abilities, we need to understand both how selection acts upon them and their genetic (co)variance structure. Recent work suggests that there are fitness consequences for free-living individuals with particular cognitive abilities. However, our current understanding of the heritability of these abilities is restricted to domesticated species subjected to artificial selection. We investigated genetic variance for, and genetic correlations among four cognitive abilities: inhibitory control, visual and spatial discrimination, and spatial ability, measured on >450 pheasants, Phasianus colchicus, over 4 generations. Pheasants were reared in captivity but bred from adults that lived in the wild and hence, were subject to selection on survival. Pheasant chicks are precocial and were reared without parents, enabling us to standardise environmental and parental care effects. We constructed a pedigree based on 15 microsatellite loci and implemented animal models to estimate heritability. We found moderate heritabilities for discrimination learning and inhibitory control (h2=0.17-0.23) but heritability for spatial ability was low (h2=0.09). Genetic correlations among-traits were largely positive but characterised by high uncertainty and were not statistically significant. Principle component analysis of the genetic correlation matrix estimate revealed a leading component that explained 69% of the variation, broadly in line with expectations under a general intelligence model of cognition. However, this pattern was not apparent in the phenotypic correlation structure which was more consistent with a modular view of animal cognition. Our findings highlight that the expression of cognitive traits is influenced by environmental factors which masks the underlying genetic structure.Pheasant cognition and pedigree data
Pheasant cognitive performances.csv
Pheasant pedigree.csv
R code for Animal models
R code for analysis in MS
Funding provided by: H2020 European Research CouncilCrossref Funder Registry ID: http://dx.doi.org/10.13039/100010663Award Number: Funding provided by: Natural Environment Research CouncilCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000270Award Number
Author Correction: Transcriptomic and epigenetic responses to short-term nutrient-exercise stress in humans
No full textA correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.</jats:p
Do detour tasks provide accurate assays of inhibitory control?
No full textThis is the author accepted manuscript. The final version is available from Royal Society via the DOI in this record.Transparent Cylinder and Barrier tasks are used to purportedly assess inhibitory control in a variety of animals. However, we suspect that performances on these detour tasks are influenced by non-cognitive traits, which may result in inaccurate assays of inhibitory control. We therefore reared pheasants under standardized conditions and presented each bird with two sets of similar tasks commonly used to measure inhibitory control. We recorded the number of times subjects incorrectly attempted to access a reward through transparent barriers, and their latencies to solve each task. Such measures are commonly used to infer the differential expression of inhibitory control. We found little evidence that their performances were consistent across the two different Putative Inhibitory Control Tasks (PICTs). Improvements in performance across trials showed that pheasants learned the affordances of each specific task. Critically, prior experience of transparent tasks, either Barrier or Cylinder, also improved subsequent inhibitory control performance on a novel task, suggesting that they also learned the general properties of transparent obstacles. Individual measures of persistence, assayed in a third task, were positively related to their frequency of incorrect attempts to solve the transparent inhibitory control tasks. Neophobia, Sex and Body Condition had no influence on individual performance. Contrary to previous studies of primates, pheasants with poor performance on PICTs had a wider dietary breadth assayed using a free-choice task. Our results demonstrate that in systems or taxa where prior experience and differences in development cannot be accounted for, individual differences in performance on commonly used detour-dependent PICTS may reveal more about an individual's prior experience of transparent objects, or their motivation to acquire food, than providing a reliable measure of their inhibitory control.J.R.M., M.A.W. and J.O.v.H. were funded by an ERC consolidator grant (616474)
Source code and data for: Spatial cognitive ability is associated with speed of movement in the early exploration of an environment
No full textFor any questions about the code please contact Christine at [email protected]
To use any data contained in this repository contact Joah at [email protected] for permission.
Code:
The data for the following /code sections are found in /data, apart from the full filtered movement dataset (used in `1_cleaning and run HMM.R`) as it is too large to be included here. Figures created using this code are stored in /figs
1_cleaning and run HMM.R: Some extra cleaning of pheasant movement data and subsetting so that only birds that have 7 days of data (of at least 6 hours) are present in the dataset. The beginning section R code is an example only as the data is not available on this repository. The data can be retrieved from Christine or Joah. However, the code shows how the subsequent files that are included here are created and how we ran Hidden Markov models.
2_Choose HMM and describe states and HRs.R: This code shows how we chose the best HMM to describe state transitions. We also use the same dataset to create HRs that are shown in Fig 2 of the manuscript.
3_Statistics.R: This code performs the statistics used in the manuscript as well as some figures.
4_ESM.R: This code produces the figures found in the supplementary material
Erratum to: Differences in social preference between the sexes during ontogeny drive segregation in a precocial species
No full text
