Urban-nesting mountain chickadees have a reduced response to a simulated predator

Anti-predator behaviour is common among birds, but little research exists on whether differences in the predator landscape between urban and rural habitats results in differential anti-predator behaviour. We compared nest-defence behaviour of mountain chickadees (Poecile gambeli) in urban and rural habitats in Kamloops, BC, Canada to a simulated predator model (snake) on top of nest boxes while incubating females were away from nests on foraging bouts. Upon their return, we recorded proximity to the predator model, latency to contact the nest box and enter the nest, and number of gargle and chick-a-dee calls as measures of anti-predator behaviour and compared multivariate “predator aversion scores” across birds occupying either rural or urban landscapes. Rural-nesting birds had more aversive reactions to the predator model than the urban-nesting birds, which may suggest differences in perceived threat of the model, in combination with increased boldness associated with urban-nesting birds.

Mussel memory: bivalves learn to fear parasites

Fear plays a crucial role in predator-prey interactions and can have cascading impacts on the structure of whole ecosystems. Comparable fear effects have recently been described for hosts and their parasites but our understanding of the underlying mechanisms remains limited by the lack of empirical examples. Here, we experimentally tested if bivalves Mytilus edulis can "learn to fear" the infective transmission stages (cercariae) of the trematode Himasthla elongata and if experienced mussels change their parasite-avoidance behaviour accordingly. Our results show that previous experience with parasites, but not infection per se, lead to a reduced filtration activity in mussels in the presence of cercariae compared to parasite-naive conspecifics. This reduction in filtration activity resulted in lower infection rates in mussels. Since parasite avoidance comes at the cost of lower feeding rates, mussels likely benefit from the ability to adjust their defence behaviour when infection risks are high. Overall, these dynamic learning processes of avoidance behaviour can be expected to play a significant role in regulating the bivalves' ecosystem engineering function in coastal habitats.

Experimental evidence that chronic outgroup conflict reduces reproductive success in a cooperatively breeding fish

Conflicts with conspecific outsiders are common in group-living species, from ants to primates, and are argued to be an important selective force in social evolution. However, whilst an extensive empirical literature exists on the behaviour exhibited during and immediately after interactions with rivals, only very few observational studies have considered the cumulative fitness consequences of outgroup conflict. Using a cooperatively breeding fish, the daffodil cichlid (Neolamprologus pulcher), we conducted the first experimental test of the effects of chronic outgroup conflict on reproductive investment and output. ‘Intruded’ groups received long-term simulated territorial intrusions by neighbours that generated consistent group-defence behaviour; matched ‘Control’ groups (each the same size and with the same neighbours as an Intruded group) received no intrusions in the same period. Intruded groups had longer inter-clutch intervals and produced eggs with less protein than Control groups. Despite this lower egg investment, Intruded groups provided more parental care, achieving similar hatching success to Control groups. Ultimately, however, Intruded groups had fewer and smaller surviving offspring than Control groups at 1-month post-hatching. We therefore provide experimental evidence that outgroup conflict can decrease fitness via cumulative effects on reproductive success, confirming the selective potential of this empirically neglected aspect of sociality.

Dynamics in brain activation and behaviour in acute and repeated social defensive motivated behaviour

In nature, confrontations between conspecifics are recurrent and related, in general, to the lack of resources such as food and territory. In this sense, adequate defence against a conspecific aggressor is essential for the individual’s survival and the group integrity. However, repeated social defeat is a significant stressor, promoting several behavioural changes, including on social defence per se. But what would be the neural basis of these behavioural changes? To explore some hypotheses about this, we investigated the effects of repeated social stress on neural circuits underlying the motivated behaviour social defence in male mice. The hypothalamus is an essential centre of these circuits. Different hypothalamic structures receive information about the conspecific from the medial amygdala and the bed nucleus of the terminal stria. Furthermore, the hypothalamus can receive environmental information via the septo-hippocampal-hypothalamic circuit. Both information is processed by the dorsal premammillary nucleus (PMD) and the ventrolateral portion of the ventromedial nucleus of the hypothalamus, which communicate with the periaqueductal grey, an important downstream site for behavioural emission. During our analysis, we observed that animals re-exposed three times to the aggressor spent more time in passive defence during their last exposure than in their first one. These animals also present a smaller mobilization of areas related to the processing of conspecific cues. In contrast, we did not observe changes in the PMD mobilization. Therefore, our data indicate that the balance between the activity of circuits related to conspecific processing and the PMD determines the pattern of social defence behaviour. Changes in this balance may be the basis of the adaptations in social defence after repeated social defeat.

Endocrine regulation of egg rejection in an avian brood parasite host

Parasite–host coevolution can lead to novel behavioural adaptations in hosts to resist parasitism. In avian obligate brood parasite and host systems, many host species have evolved diverse cognitive and behavioural traits to recognize and reject parasitic eggs. Our understanding of the evolution and ecology of these defences hinges on identifying the mechanisms that regulate them. We hypothesized that corticosterone, a hormone linked to stress response, vigilance and the suppression of parental behaviour, stimulates the rejection of foreign eggs by brood parasite hosts. We experimentally reduced circulating glucocorticoid levels with mitotane injections in American robins Turdus migratorius and found that the mitotane-treated birds rejected foreign eggs at a lower frequency compared to the sham-treated subjects. This is the first study to causally identify a potential mechanism of a widespread defence behaviour, and it is consistent with egg rejection being mediated by stress physiology.

Structure–behaviour correlations between two genetically closely related snail species

Species, through their structure and composition, have evolved to respond to environmental constraints. Predator–prey interactions are among environmental pressures that can lead to speciation, but it remains unclear how this pressure can be related to the material structure and performance. Recently, two land snails, Karaftohelix editha and Karaftohelix gainesi , were found to exhibit divergent phenotypes and responses to predation despite sharing the same habitat and most of their genome. Indeed, under attack from a beetle, K. editha snails retract into their shell whereas K. gainesi snails swing their shell. In this paper, we looked at the microstructure, composition, morphology and mechanics of the shells of those two species and discuss potential relationships between material structure and the snail defence behaviour. The results of this study provide additional arguments for the role of predator–prey interactions on speciation, as well as an unusual approach for the design of biomimetic structures adapted to a particular function.

Threat and Anxiety in the Climate Debate:An Agent-Based Model to investigate Climate Scepticism and Pro-Environmental Behaviour

How people react to threatening information such as climate change is a complicated matter. While people with a high environmental self-identity tend to react approach-motivated by engaging in pro-environmental behaviour, people of low environmental self-identity may exhibit proximal defence behaviour, by avoiding and distracting themselves from potentially threatening stimuli caused by identified anxious thoughts and circumstances. This psychological theory has recently been tested in experimental studies in which the results suggest that the promotion of climate change information can also backfire. Based on these findings, we propose an agent-based model to address influences on anxiety and correlated pro-environmental actions in relation to societal attitudes of climate change scepticism and environmental self-identity.

Threat and Anxiety in the Climate Debate:An Agent-Based Model to investigate Climate Scepticism and Pro-Environmental Behaviour

How people react to threatening information such as climate change is a complicated matter. While people with a high environmental self-identity tend to react approach-motivated by engaging in pro-environmental behaviour, people of low environmental self-identity may exhibit proximal defence behaviour, by avoiding and distracting themselves from potentially threatening stimuli caused by identified anxious thoughts and circumstances. This psychological theory has recently been tested in experimental studies in which the results suggest that the promotion of climate change information can also backfire. Based on these findings, we propose an agent-based model to address influences on anxiety and correlated pro-environmental actions in relation to societal attitudes of climate change scepticism and environmental self-identity.

IMPLEMENTASI PROSES PEMBELAJARAN PENDIDIKAN KEWARGANEGARAAN BAGI PENGEMBANGAN SEMANGAT BELA NEGARA MAHASISWA

This study is back grounded by author’s anxiety toward the fading of state defence spirit of citizen included college students. This study use qualitative approach with descriptive method. Data of study is obtained by interview, observation, and documentation study. Result of study reveal that: 1) Lecturer team of Civic Education, MKDU Department develop Syllabus by concerning student’s cognitive, affective and psychomotor domain, then this Syllabus is used to become reference to develop Lecturing Program Unit by civic education lecturers; 2) Syllabus and Lecturing Program Unit that have been designed in implementation in class undergo much adjustments; 3) The development of student’s state defence spirit is done in learning process by discussing more deeply Indonesia geo politic and geo strategy topics because state defence topic is integrated in those two subject matter. Whereas strategy that is implemented by lecturer is by giving example of state defence behaviour and through the story of nation struggle history that contain nationalism and patriotism value; 4) State defence spirit is done by college student by learning persistently to actualize knowledge potency, active in university student affair organization, have achievement, fortify him/herself from negative foreign culture, and apply Indonesian-ness values in attitude and behaved. Thus, college student’s predicate as agent of change, social control, and iron stock can be actualized, because self devote according to his/her profession and predicate as a college students for the sake of nation and state interest included in state defence.