Chemoreception and the Assessment of Fighting Abilities in the Lizard Liolaemus monticola

When an individual faces the risk of a conflict, its ability to make ‘correct’ decisions is crucial to its fitness. Research on decision making has focused mainly on visual and acoustic signals, while chemical signals have received much less attention, despite their relevance for many species. Chemosignals can be detected in the absence of the signaller and, in the context of fighting risk, this property confers the advantage that the receiver can avoid agonistic interactions or, if they are unavoidable, that it can prepare itself for the conflict. I studied the behaviour of males of the lizard Liolaemus monticola in the laboratory when they were confronted with chemosignals of a potential opponent. During this ‘pre‐confrontation’ stage, I tested the following predictions: (1) lizards can derive precise information from chemosignals of conspecifics, and use this to respond with precision to the perceived risk and (2) the best predictor of the receiver behaviour, and therefore the best predictor of the risk involved in the fight, is the relative fighting ability of opponents. As a measure of fighting ability, I used body size. ‘Intruders’ were placed in the terrarium of unfamiliar ‘residents’ during the absence of the latter, and their behaviours were recorded. Simple regressions were performed between the different behavioural variables and with the body sizes of intruder and resident, and with the relative difference in body sizes of opponents. The latter was the best predictor of intruder behaviour: it was negatively correlated with behaviours associated with activity (i.e. motion time), chemoexploration (i.e. number of tongue flicks) and behaviours associated with social interactions (i.e. head bobs). These results suggest that males can process information from chemosignals and decisions made during the ‘pre‐confrontation’ stage are based on the assessment of the relative fighting abilities (i.e. relative body size) of opponents.     

The evolution of respect for property

Although possession is ‘nine‐tenths of the law’, respect for ownership is widespread in the animal kingdom even without third‐party enforcement. Thus, the first individuals to find objects are frequently left unchallenged by potential competitors and tend to win contests when disputes arise. Game theory has shown that respect for ownership (‘Bourgeois’ behaviour) can arise as an arbitrary convention to avoid costly disputes. However, the same theory predicts that a paradoxical respect for lack of ownership (‘anti‐Bourgeois’ behaviour) can evolve under the same conditions and in some cases is the only stable outcome. Despite these predictions, anti‐Bourgeois behaviour is rare in nature, whereas respect for ownership is frequently not absolute. Here, we review extensions of the classic models involving repeated interactions, confusion over roles, strategic coordination of behaviour (‘secret handshakes’), owner–intruder asymmetries and continuous control of fighting investment. Confusion over roles and owner–intruder asymmetries in fighting ability may explain why respect for ownership is often partial. Moreover, although most model extensions facilitate the evolution of Bourgeois‐like behaviour, secret handshakes and continuous control of fighting investment render the alternative anti‐Bourgeois convention unstable. We develop these insights to highlight several key areas for future investigation.     

The role of asymmetries in animal contests

This paper contains a game theoretical analysis of animal contest situations which are asymmetric in more than one aspect: two opponents may for example be imagined which differ in ‘ownership status’ as well as in ‘relative fighting ability’. The following question is analysed: which aspect may or must be used for conventional settlement in a population ‘playing’ an evolutionarily stable strategy (ESS)? The contestants are assumed to be fully informed about the asymmetric features. In particular, the assessment of relative fighting ability is supposed to be unambiguous and without cost. This assumption of perfect information allows for a decomposition of the ‘evolutionary game’ into sub-games. Therefore an easy procedure for calculating the ESS's can be presented, and simple models are analysed. It is concluded that payoff-irrelevant aspects may be used for conventional settlement of a conflict even if payoff-relevant asymmetric aspects also exist. One of the aspects may, however, be of such strong relevance that, no matter which ESS is played, animals must base their decisions on that ‘dominant’ aspect. It may also occur that two different asymmetric features are each of strong payoff relevance for either of the opponents, such that they have no escalation-suppressing effect. The particular scenario of a conflict between an ‘owner of a resource’ and an ‘intruder’ is used to derive the more general conclusions.     

Apomorphine induced biting and fighting behaviour in reserpinized rats and an approach to the mechanism of action

Various patterns of aggressive behaviour have been induced by drugs. In the present study, the biting and the fighting responses were induced in rats by apomorphine alone, and reserpine plus apomorphine combination respectively, and these could be blocked completely by a dopamine receptor blocking agent. Dopamine, norepinephrine and clonidine given intraperitoneally or intraventricularly failed to induce these responses. Chemical agents known to increase the concentration of dopamine in the brain, induced the biting, but not the fighting response, whereas these behavioural patterns were more intense due to apomorphine in the rats pretreated with reserpine and dopamine or α-methyltyrosine and reserpine combinations. In amphetamine pretreated rats, apomorphine induced intense biting after 10 min and a few bouts of fighting after 30 min. It is suggested that (i) the receptors on which apomorphine acts may be called ‘Apomorphine Receptor’ rather than ‘Dopamine Receptor’, (ii) dopamine incompletely activates these receptors which are sensitised in the absence of catecholamines and induce a higher degree of stereotyped behaviour i.e. fighting, due to apomorphine.     

Beyond the senses: perception,the environment,and vision impairment

The ‘sensory turn’ in anthropology has generated a significant literature on sensory perception and experience. Whilst much of this literature is critical of the compartmentalization of particular ‘senses’, there has been limited exploration of how anthropologists might examine sensory perception beyond ‘the senses’. Based on ethnographic fieldwork with people who have impaired vision walking the South Downs landscape in England, this article develops such an approach. It suggests that the experiences of seeing in blindness challenge the conceptualization of ‘vision’ (and ‘non-vision’). In place of ‘vision’ (as a sense), the article explores ‘activities of seeing’ – an approach that contextualizes the visual to examine the biographically constituted and idiosyncratic nature of perception within an environment. Through an ethnography of seeing with anatomical eyes and ‘seeing in the mind's eye’, it articulates an approach that avoids associating perception with anatomy, or compartmentalizing experience into ‘senses’.     

Dominance, Status Signals and Coloration in Male Mandrills (Mandrillus sphinx)

Where individuals contest access to a resource, escalated physical fighting presents a risk to all involved. The requirement for mechanisms of conflict management has led to the evolution of a variety of decision rules and signals that act to reduce the frequency of aggression during competitive encounters. We examined strategies of conflict management in male mandrills (Mandrillus sphinx) living in two semi‐free‐ranging groups in Gabon. Adult male mandrills are large (31 kg), with long canines, making the costs of conflict potentially very high. We found that males formed dominance hierarchies, but that male–male relationships were characterized by avoidance, appeasement and ignoring. Fights were rare, but could result in death. Examination of the relationship between dominance and signaling showed that males use facial and gestural signals to communicate dominance and subordinance, avoiding escalated conflict. Male mandrills also possess rank‐dependent red coloration on the face, rump and genitalia, and we examined the hypothesis that this coloration acts as a ‘badge of status’, communicating male fighting ability to other males. If this is the case, then similarity in color should lead to higher dyadic rates of aggression, while males that differ markedly should resolve encounters quickly, with the paler individual retreating. Indeed, appeasement (the ‘grin’ display), threats, fights and tense ‘stand‐off’ encounters were significantly more frequent between similarly colored males, while clear submission was more frequent where color differences were large. We conclude that male mandrills employ both formal behavioral indicators of dominance and of subordination, and may also use relative brightness of red coloration to facilitate the assessment of individual differences in fighting ability, thereby regulating the degree of costly, escalated conflict between well‐armed males.     

Templates and exclusions: victim centrism in Canada's Truth and Reconciliation Commission on Indian residential schools

In this article I use an ethnographic approach to consider the causes and consequences of a focus on ‘survivor’ experience in Canada's Truth and Reconciliation Commission (TRC) on Indian residential schools. In this Truth Commission, the interconnected concepts of ‘survivor’, ‘cultural genocide’, ‘trauma’, and ‘healing’ became reference points for much of the testimony that was presented and the ways the schools were represented. Canada's Truth Commission thus offers an example of the consequences of ‘victim centrism’, including the ways that ‘truth‐telling’ can be influenced by the affirmation of particular survivor experiences and the wider goal of reforming the dominant historical narrative of the state through public education. Canada's TRC was limited by its mandate to a particular kind of institution and scope of collective harm. It was at the same time active in its creation of narrative templates, which guided the expression of traumatic personal experience and affirmed the category of residential school ‘survivor’ as the focal point for understanding policy‐driven loss of language, tradition, and political integrity.     

MODULATION OF THE TURNOVER RATE OF ACETYLCHOLINE IN RAT BRAIN BY INTRAVENTRICULAR INJECTIONS OF THYROTROPIN-RELEASING HORMONE, SOMATOSTATIN, NEUROTENSIN AND ANGIOTENSIN II

The turnover rate of acetylcholine (TR_ACh) was measured in frontal and parietal cortex striatum, hippocampus, diencephalon and brain stem following the intraventricular injection of thyrotropin-releasing hormone (TRH), somatostatin, neurotensin and angiotensin II. These peptides selectively change the TR_ACh of various brain regions suggesting specific and independent actions. This specificity of action was also tested by injecting L-prolylglycine, poly-L-proline and poly-L-glutamate. None of these synthetic peptides affect the TR_ACh. TRH increases the TR_ACh in parietal but not in frontal cortex whereas somatostatin, neurotensin and angiotensin II failed to change the TR_ACh in these cortical areas. Somatostatin and neurotensin increase the TR_ACh in diencephalon, whereas TRH and angiotensin II do not. All four peptides decrease the acetylcholine (ACh) content of parietal cortex but not that of frontal cortex. Only somatostatin changes the TR_ACh in pons medulla. Larger doses of TRH, neurotensin and angiotensin II fail to elicit greater or more general changes in TR_ACh. In contrast, high doses of somatostatin increase the TR_ACh of hippocampus and induce‘barrel’rotation. Intraseptal injections of somatostatin induce a long lasting catalepsy but fail to change hippocampal TR_ACh or to elicit‘barrel’rotation     

Role assessment,reserve strategy,and acquisition of information in asymmetric animal conflicts

It was formerly argued that alternative evolutionarily stable strategies (ESSs) are possible for animal contests characterized by some asymmetry that can be perceived with perfect accuracy. Where roles A and B refer to the asymmetry between opponents, ESSs are: ‘fight when A, retreat when B’, and vice versa. Either can be an ESS, but only if the ‘reserve strategy’ (=what an animal does when it fights) is sufficiently damaging. We examine the ‘war of attrition’ (winner = opponent that persists longer). In a population at either ESS, reserve strategy is never normally shown; it is therefore subject to drift unless the selective action of rare individuals which break the convention is considered. These could arise either by mutation or by mistakes in role assessment. When mutations and mistakes simply specify that occasionally an animal fights when it ‘should’ retreat, selection adjusts reserve strategy to a level where only one ESS (the ‘commonsense’ ESS) is possible, if the asymmetry is relevant to payoff. Thus for asymmetries in fighting ability or resource value, the individual with the lower score will retreat. However, we are particularly concerned with cases where both payoff-relevant aspects (fighting ability and resource value) are asymmetric. If opponents sustain contest costs at rates K_A and K_B, and their resource values are V_A and V_B, an ‘optimal assessor’ strategy defined by the interaction between the two asymmetries, is a unique ESS. It obeys the rule ‘fight on estimating role A, where V_A/K_A>V_B/K_B; retreat in B’. If mistakes can occur in both roles, but are very rate, the ESS is not fundamentally altered though there will be infinitesimal tendencies for persisting in role B. Selection to improve assessment abilities intensifies as abilities improve, but is weak if roles A and B are rather similar. Over a range of similarity between roles, an ‘owner wins’ convention may be adopted if ownership correlates positively with role A and an individual cannot tell when it would otherwise pay him to break the convention. We also examine a contest in which information about roles can be acquired only during a contest itself, and at a cost. Much depends on the rate at which information is acquired relative to the rate at which costs are expended, and on whether contests normally escalate in intensity, remain at the same level, or de-escalate. Selection favours short contests when costs are high relative to resource value, where the outcome of a round contains much information about fighting ability, and where the actual disparity in fighting ability is large.     

Inhibition of affective aggression and dominance in rats after thyrotropin-releasing hormone (TRH) microinjection into the nucleus accumbens

The effect of 10 micrograms TRH injected bilaterally into the nucleus accumbens septi on two models of affective aggression and on dominance in a water-competition task was investigated in pairs of male Wistar rats. TRH significantly suppressed affective shock-induced and apomorphine-induced fighting. It also decreased dominance when administered to dominant rats while no effect was noted upon injection into subordinate animals. The peptide influenced neither water consumption in thirsty rats nor the pain threshold in a hot plate test.     

Role of corticosterone in the control of post-shock fighting behaviour in male laboratory mice

Two experiments were conducted to examine the role of corticosterone in controlling fighting subsequent to electric foot-shock in male mice. It was found that (1) treatment with corticosterone restores post-shock fighting in adrenalectomized males but not in castrated-adrenalectomized males; (2) raising cortieosterone levels induces post-shock fighting in castrated-adrenalectomized males treated with testosterone but not in castrated-adrenalectomized controls treated with a placebo; and (3) preventing corticosterone responses to shock occludes the increasing in fighting which normally follow shock in intact males. These findings suggest that (1) corticosterone plays an important role in the control of post-shock fighting in mice; (2) this importance of corticosterone is dependent on the presence of circulating testosterone, or other androgens; and (3) corticosterone responses to the experience of shock may be involved in the mediation of the facilitatory effects of this experience on subsequent fighting behaviour.     

Examination of prior contest experience and the retention of winner and loser effects

In many animal taxa, prior contest experience affects future performance such that winning increases the chances of winning in the future (winner effect) and losing increases the chances of losing in the future (loser effect). It is, however, not clear whether this pattern typically arises from experience effects on actual or perceived fighting ability (or both). In this study, we looked at winner and loser effects in the jumping spider Phidippus clarus. We assigned winning or losing experience to spiders and tested them against opponents of similar fighting ability in subsequent contests at 1-, 2-, 5-, and 24-h intervals. We examined the strength of winner and loser effects, how long effects persist, as well as how experience affected perceived and actual fighting ability. Our results demonstrate that winner and loser effects are of approximately the same magnitude, although loser effects last longer than winner effects. Our results also demonstrate that previous experience alters actual fighting ability because both the assessment and escalation periods were affected by experience. We suggest that the retention time of experience effects depends on expected encounter rates as well as other behavioral and ecological factors. In systems with short breeding seasons and/or rapidly fluctuating populations, context-dependent retention of experience effects may allow males to track their status relative to the fluctuating fighting ability of local competitors without paying the costs necessary to recall or assess individual competitors.     

The limitations of ‘inter-racial contact’: stories from young South Africa

This paper argues that, while the demise of apartheid has led to many situations in which South Africans now come into closer contact with one another, this increased ‘contact’ does not amount to greater racial integration. Contact occurs within a context of unequal power relations in which ‘whiteness’ continues to be privileged over ‘blackness’. The result is that white people tend to benefit more from contact with the racial ‘other’ than black people, who often experience this contact as reinforcing their expectations of continued white dominance and privilege. While contact may undermine blatantly racist practices and overt racial conflict, racialized patterns of reasoning continue to exist, often unnoticed and unchallenged. These include the assumption that race is an incontrovertible fact of experience, the privileging of whiteness, the assumption that there exist different (biological) races which evince different forms of social behaviour and that these are essential properties of people rather than being historically or socially contingent.     

On the function of the ‘eye-spots’ in agonistic behaviour in the fire-mouth cichlid (Cichlasoma Meeki)

During frontal threatening, individuals of the fire-mouth cichlid (Cichlasoma meeki) dilate their opercula, thereby demonstrating two conspicous ‘eye-spots’. In a hostile situation, a fish confronted with an opponent whose eye-spots have been experimentally removed is more likely to react with overt aggression towards the other. Fights also follow a more violent course than does a ‘normal’ fight between two intact males. A tentative explanation to these results is advanced which supposes that the eye-spots may exert an ‘intimidating’ effect upon the opponent during threat and fighting. This hypothesis is also supported by an experiment where males were confronted with a mirror. In this situation the distance between the mirror and the fish during frontal threat was significantly shorter in fishes lacking eye-spots, indicating that the intimidating effect emerging from the mirror image was diminished. In a third set of experiments when two males (one intact and one without eye-spots) competed for the only suitable territory site in an aquarium, the intact male eventually dominated the other in five of six aquariums.     

Out-of-school experience categories influencing interest in biology of secondary school students by gender: exploration on an Abu Dhabi sample

This study employed the international Relevance of Science Education questionnaire to survey the interest in biology and the out-of-school experiences of Abu Dhabi secondary school students (median age 17, mean age 17.53 and mode age of 16) in the third semester of 2014. It included 3100 participants. An exploratory factor analysis was used to categorise the items for both interest in biology and out-of-school experience. Ten interest in biology and 12 out-of-school experience factors were extracted. The summated means for each factor indicated that ‘health and fitness’ and ‘disease control’ enjoyed highest interests among students. For out-of-school experiences, the two factors of ‘digital applications’ and ‘medical treatment’ received the highest scores. Multivariate analysis of variance revealed that all factors for both interest in biology and out-of-school experience exhibited significant differences between boys and girls. More girls than boys were interested in disease control, reproduction (human biology), alternative science, health and fitness, zoology, and applied cosmetic biology. No significant differences were observed for the remaining five other categories. Furthermore, analysis of variance revealed significant differences between boys and girls with regard to individual items comprising each of the factors. The highest correlations were between the two factors of out-of-school experiences of ‘the natural world’ and ‘learning through observation’ and the interest in biology factor related to ‘plant and animal farming and agriculture’. Results suggested that more emphasis must be placed on students’ out-of-school experience and their engagement in informal learning in contextual outdoor environments to enhance their interest in learning more about biology and the living environment in general.     

Telling the forest from the trees: Local images of national change in a Danish town

How can ethnographers see the ‘big picture’, while they are busy with everyday minutiae? Awareness of the local impacts of history and globalisation has revived debates about the pragmatics of fieldwork. Arguing that most fieldwork remains, for most practitioners, ‘local’, this paper explores how it is possible to apprehend change ethnographically. Something of how local people understand and experience change, as it happens to them and around them and as they contribute to it, can be grasped in ‘significant local imagery’, in this case, ‘significant people’, ‘significant things’, and ‘significant events’. These images are recognised in local discourse as indicative or ‘telling’ of change, and can be used to summarise analytically, and shed light on, wider vistas of change. This paper presents three local images deriving from fieldwork in a small town in mid-Jutland and uses them to tell a bigger story, a narrative about the modernisation of Danish society.     

Seabird Group,Interim Report 1968–69

The Pinkfoot no longer subsists on a ‘natural’ food resource when in winter quarters, and few Greylags do, especially in Britain. Both take mainly grasses and cereal harvest-waste, but differences in size of bill and gizzard, and in roosting and fighting behaviour, tend to reduce interspecific competition.     

Gould and the fairies

This paper examines Stephen Jay Gould’s concept of science and religion as ‘nonoverlapping magisteria’ with reference to Spiritualism, specifically the case of the Cottingley fairies. It argues that this is a case in which the magisteria are neither separate nor overlapping but instead exist in a far more complex relationship. Through an exploration of this complexity, this paper offers discussion of the relationship between religion and science. In doing so, it problematises the common use of the terms ‘faith’ and ‘belief’ to characterise the experience of religious conviction.     

Entropy and the conceit of biodiversity management

Many conservation biologists and ecologists consider invasive species to be one of the greatest threats to biodiversity because their spread across biogeographical boundaries may endanger unique and localized expressions of biodiversity (whether species or communities). Consequently, they imagine a future, the ‘Homogocene’, in which a small set of species dominates ecosystems around the world, and they promote policies and practices to lessen the spread of these species. Here, we consider some thermodynamic dimensions of the efforts to maintain current biogeographical boundaries. We wish to explore an important conceptual analogy between thermodynamically‐closed systems and isolated biogeographical regions in ecology. The conceptual tools developed in the context of thermodynamic systems can be shown to have relevance in a wide variety of systems contexts. The ‘Maxwell's demon’ thought experiment suggests that entropy is best thought of as information‐relative rather than a ‘law of nature’. Adopting this Maxwellian thermodynamic approach to managing complexity can shed new light on the challenges of biodiversity management. To prevent the dispersion of invasive species, people must invest energy on a scale to counteract global trade and concomitant dispersal of species. We show that removing barriers to species interaction through globalization is akin to allowing a previously isolated thermal system to interact with its environment; in both cases, the system will tend towards mixing or ‘equilibrium’, and fighting this tendency is costly. Unless social and economic integration declines, the energetic input required to lessen the spread of invasive species will continue to grow.     

‘Community’ and the Re‐Making of 1970s Belfast

This article explores the fraught, shifting terrain of'community’ as lived out in 1970s Belfast. Applying Raymond Williams’ concept of ‘structures of feeling,’ it explores ‘community’ consciousness that is rooted in affection, sensation, and knowledge. It then considers campaigns against redevelopment in west Belfast at this time, and the ways they were inspired and limited by the contemporary experience of ‘community.’ Based on fieldwork, oral histories, and archival resources, the discussion proposes that political action in divided societies is not reducible to sectarian geography. Rather, it advocates analysing the historically specific contours ofnuanced emotional allegiances and spatial associations that motivate and limit political action, and attention to how social content and place figure in conceptions of collectivity.