Context-dependent responses to light contribute to responses by Black-bellied Salamanders (Desmognathus quadramaculatus) to landscape disturbances

2016 ◽  
Vol 94 (1) ◽  
pp. 7-13 ◽  
Author(s):  
K.K. Cecala ◽  
J.C. Maerz
Keyword(s):  
Environmental Change ◽  
Canopy Cover ◽  
Population Connectivity ◽  
Behavioural Plasticity ◽  
Negative Phototaxis ◽  
Behavioural Responses ◽  
Population Responses ◽  
The Face ◽  
Context Dependent ◽  
Desmognathus Quadramaculatus

Behaviour often regulates population responses to environmental change, but linking behavioural responses to population patterns can be challenging because behavioural responses are often context-dependent, have an instinctive component, and yet may be modified by experience. Black-bellied Salamanders (Desmognathus quadramaculatus (Holbrook, 1840)) occupy forested streams where dense canopies create cool, dark environments. Because riparian deforestation negatively affects salamander-population connectivity yet some individuals choose to persist in these gaps, we sought to evaluate whether phototaxis could explain these patterns and whether phototactic behaviour would be influenced by experience (capture from forested or deforested areas) or context (refuge type and availability). Our results demonstrated that larval D. quadramaculatus exhibited negative phototaxis, but that larvae from forested streams exhibited stronger negative phototaxis than individuals from deforested streams. Larvae also selected habitat closer to light when refuge was available. Our results show that light alters habitat use by larval D. quadramaculatus, but the magnitude of that effect depends on refuge availability and experience with well-lit conditions associated with forest removal. As human activities reduce canopy cover and refuge availability, negative phototaxis may be one explanation for behavioural barriers to movement. Ultimately, the ability of salamanders to exhibit behavioural plasticity will determine their potential for local adaptation facilitating persistence in the face of environmental change.

scholarly journals How do developmental and parental exposures to predation affect personality and immediate behavioural plasticity in the snail Physa acuta ?

2020 ◽  
Vol 287 (1941) ◽  
pp. 20201761
Author(s):  
Juliette Tariel ◽  
Sandrine Plénet ◽  
Emilien Luquet
Keyword(s):  
Environmental Change ◽  
Predation Risk ◽  
Behavioural Plasticity ◽  
Escape Behaviour ◽  
Developmental Exposure ◽  
Predator Cues ◽  
Physa Acuta ◽  
Behavioural Responses ◽  
Two Generations ◽  
Group Diversity

Individuals differ in personality and immediate behavioural plasticity. While developmental environment may explain this group diversity, the effect of parental environment is still unexplored—a surprising observation since parental environment influences mean behaviour. We tested whether developmental and parental environments impacted personality and immediate plasticity. We raised two generations of Physa acuta snails in the laboratory with or without developmental exposure to predator cues. Escape behaviour was repeatedly assessed on adult snails with or without predator cues in the immediate environment. On average, snails were slower to escape if they or their parents had been exposed to predator cues during development. Snails were also less plastic in response to immediate predation risk on average if they or their parents had been exposed to predator cues. Group diversity in personality was greater in predator-exposed snails than unexposed snails, while parental environment did not influence it. Group diversity in immediate plasticity was not significant. Our results suggest that only developmental environment plays a key role in the emergence of group diversity in personality, but that parental environment influences mean behavioural responses to the environmental change. Consequently, although different, both developmental and parental cues may have evolutionary implications on behavioural responses.

scholarly journals Temperament, Plasticity, and Emotions in Defensive Behaviour of Paca (Mammalia, Hystricognatha)

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 293
Author(s):  
Selene S. C. Nogueira ◽  
Sérgio L. G. Nogueira-Filho ◽  
José M. B. Duarte ◽  
Michael Mendl
Keyword(s):  
Conservation Status ◽  
Behavioural Plasticity ◽  
Affective States ◽  
Defensive Behaviour ◽  
Rapid Adaptation ◽  
Behavioural Responses ◽  
Judgement Bias ◽  
Temperament Dimension ◽  
Ambiguous Cue

Within a species, some individuals are better able to cope with threatening environments than others. Paca (Cuniculus paca) appear resilient to over-hunting by humans, which may be related to the behavioural plasticity shown by this species. To investigate this, we submitted captive pacas to temperament tests designed to assess individual responses to short challenges and judgement bias tests (JBT) to evaluate individuals’ affective states. Results indicated across-time and context stability in closely correlated “agitated”, “fearful” and “tense” responses; this temperament dimension was labelled “restless”. Individual “restless” scores predicted responses to novelty, although not to simulated chasing and capture by humans in a separate modified defence test battery (MDTB). Restless animals were more likely to show a greater proportion of positive responses to an ambiguous cue during JBT after the MDTB. Plasticity in defensive behaviour was inferred from changes in behavioural responses and apparently rapid adaptation to challenge in the different phases of the MDTB. The results indicate that both temperament and behavioural plasticity may play a role in influencing paca responses to risky situations. Therefore, our study highlights the importance of understanding the role of individual temperament traits and behavioural plasticity in order to better interpret the animals’ conservation status and vulnerabilities.

Behavioural responses of Australian freshwater crayfish (Cherax cainii and Cherax albidus) to exotic fish odour

2006 ◽  
Vol 54 (6) ◽  
pp. 399 ◽  
Author(s):  
S. G. Height ◽  
G. J. Whisson
Keyword(s):  
Western Australia ◽  
Predatory Fish ◽  
Behavioural Plasticity ◽  
Current Debate ◽  
Freshwater Crayfish ◽  
Indigenous Species ◽  
Exotic Fish ◽  
Behavioural Responses ◽  
Invasive Crayfish ◽  
Australian Freshwater

Exotic finfish and crayfish have been translocated into Western Australia for more than 100 years. Deliberate stocking and subsequent escape from man-made impoundments have resulted in widespread distribution of non-native yabbies (Cherax albidus) and the exotic redfin perch (Perca fluviatilis) in the State’s south-west. Both species are considered invasive and are known to compete with indigenous species for resources. The nature and degree of impact on native marron (Cherax cainii) is unclear and the subject of current debate. Other researchers have hypothesised that invasive species modify their behaviour in the presence of predators in a more rapid and advantageous manner than native species. This greater behavioural plasticity can result in displacement of indigenous species and successful colonisation of invaders. The aim of this study was to investigate behavioural responses of an indigenous crayfish (C. cainii) and an invasive crayfish (C. albidus) to odours from a native predator (Tandanus bostocki) and an exotic predatory fish (P. fluviatilis) present in Western Australia. Crayfish behaviour was observed in individual glass tanks following the addition of odours from native (T. bostocki) or exotic (P. fluviatilis) finfish predators. Marron exhibited minor behavioural modifications when presented with odours from native or exotic finfish. In contrast, the invasive yabby showed greater detection of odours, displaying significant changes in behaviour (P < 0.05). Yabbies also appeared to distinguish between food odour (commercial crayfish feed) and predator odour; however, neither marron nor yabbies displayed behaviour indicating that they could distinguish between a native or exotic fish predator. Results support the hypothesis that invasive crayfish species have a greater capacity for behavioural plasticity than non-invasive crayfish.

Flying in the face of environmental change

2001 ◽  
Vol 17 (11) ◽  
pp. 553-554 ◽  
Author(s):  
A.M Jordan
Keyword(s):  
Environmental Change ◽  
The Face

scholarly journals Context-dependent expression of the foraging gene in field colonies of ants: the interacting roles of age, environment and task

2016 ◽  
Vol 283 (1837) ◽  
pp. 20160841 ◽  
Author(s):  
Krista K. Ingram ◽  
Deborah M. Gordon ◽  
Daniel A. Friedman ◽  
Michael Greene ◽  
John Kahler ◽  
...  
Keyword(s):  
Gene Expression ◽  
Task Allocation ◽  
Molecular Mechanisms ◽  
Light Exposure ◽  
Genetic Regulation ◽  
Behavioural Plasticity ◽  
Harvester Ants ◽  
Ontogenetic Changes ◽  
Context Dependent ◽  
And Task

Task allocation among social insect workers is an ideal framework for studying the molecular mechanisms underlying behavioural plasticity because workers of similar genotype adopt different behavioural phenotypes. Elegant laboratory studies have pioneered this effort, but field studies involving the genetic regulation of task allocation are rare. Here, we investigate the expression of the foraging gene in harvester ant workers from five age- and task-related groups in a natural population, and we experimentally test how exposure to light affects foraging expression in brood workers and foragers. Results from our field study show that the regulation of the foraging gene in harvester ants occurs at two time scales: levels of foraging mRNA are associated with ontogenetic changes over weeks in worker age, location and task, and there are significant daily oscillations in foraging expression in foragers. The temporal dissection of foraging expression reveals that gene expression changes in foragers occur across a scale of hours and the level of expression is predicted by activity rhythms: foragers have high levels of foraging mRNA during daylight hours when they are most active outside the nests. In the experimental study, we find complex interactions in foraging expression between task behaviour and light exposure. Oscillations occur in foragers following experimental exposure to 13 L : 11 D (LD) conditions, but not in brood workers under similar conditions. No significant differences were seen in foraging expression over time in either task in 24 h dark (DD) conditions. Interestingly, the expression of foraging in both undisturbed field and experimentally treated foragers is also significantly correlated with the expression of the circadian clock gene, cycle . Our results provide evidence that the regulation of this gene is context-dependent and associated with both ontogenetic and daily behavioural plasticity in field colonies of harvester ants. Our results underscore the importance of assaying temporal patterns in behavioural gene expression and suggest that gene regulation is an integral mechanism associated with behavioural plasticity in harvester ants.

scholarly journals Predicting behavioural responses to novel organisms: state-dependent detection theory

2017 ◽  
Vol 284 (1847) ◽  
pp. 20162108 ◽  
Author(s):  
Pete C. Trimmer ◽  
Sean M. Ehlman ◽  
Andrew Sih
Keyword(s):  
Environmental Change ◽  
Signal Detection Theory ◽  
Novel Species ◽  
Detection Theory ◽  
The Novel ◽  
Natural Habitats ◽  
Behavioural Responses ◽  
State Dependent ◽  
Optimal Thresholds ◽  
Adaptive Thresholds

Human activity alters natural habitats for many species. Understanding variation in animals' behavioural responses to these changing environments is critical. We show how signal detection theory can be used within a wider framework of state-dependent modelling to predict behavioural responses to a major environmental change: novel, exotic species. We allow thresholds for action to be a function of reserves, and demonstrate how optimal thresholds can be calculated. We term this framework ‘state-dependent detection theory’ (SDDT). We focus on behavioural and fitness outcomes when animals continue to use formerly adaptive thresholds following environmental change. In a simple example, we show that exposure to novel animals which appear dangerous—but are actually safe—(e.g. ecotourists) can have catastrophic consequences for ‘prey’ (organisms that respond as if the new organisms are predators), significantly increasing mortality even when the novel species is not predatory. SDDT also reveals that the effect on reproduction can be greater than the effect on lifespan. We investigate factors that influence the effect of novel organisms, and address the potential for behavioural adjustments (via evolution or learning) to recover otherwise reduced fitness. Although effects of environmental change are often difficult to predict, we suggest that SDDT provides a useful route ahead.

The endocrine response to stress

2011 ◽  
pp. 287-294
Author(s):  
David E. Henley ◽  
Joey M. Kaye ◽  
Stafford L. Lightman
Keyword(s):  
Stress Response ◽  
Initial Exposure ◽  
Behavioural Responses ◽  
Physiological Processes ◽  
Psychological Stressors ◽  
Endocrine Stress Response ◽  
The Face ◽  
Response To Stress ◽  
Trauma Injury ◽  
As Stress

In the face of any threat or challenge, either real or perceived, an organism must mount a series of coordinated and specific hormonal, autonomic, immune, and behavioural responses that allow it to either escape or adapt (1–3). To be successful, the characteristics and intensity of the response must match that posed by the threat itself and should last no longer than is necessary. A response that is either inadequate or excessive in terms of its specificity, intensity or duration may result in one or more of a multitude of psychological or physical pathologies (2–5). This concept of threat and the organism’s response to it is frequently recognized and understood as ‘stress’ but is so diverse that it lacks a universally accepted definition (2) and thus is difficult to investigate or study (6). In the early 1900s, Walter Cannon introduced the concept of homoeostasis (4)—an ideal steady state for all physiological processes. Stress has been defined as the state where this ideal is threatened. More easily appreciated, however, are those factors, both intrinsic and extrinsic, which represent a challenge to homoeostasis (termed stressors) and the complex physiological, hormonal, and behavioural responses that occur to restore the balance, the stress response (1). The importance of endocrine systems in this stress response was emphasized by Hans Selye (7), who described the need for multiple, integrated systems to respond in a coordinated fashion following exposure to a particular stressor. Nonspecific activation of the hypothalamic–pituitary–adrenal (HPA) and sympatho-adrenomedullary (SAM) axes occurred following initial exposure to a noxious stimulus. Continued exposure to the same agent has been shown to have lasting and damaging effects on various endocrine, immune, and other systems, although recovery from this state was possible provided the stress was terminated (7). In addition to various noxious agents, numerous potential stressors exist including exertion, physical extremes, trauma, injury, and psychological stress. Indeed, psychological stressors are some of the most potent stimuli of the endocrine stress response particularly when they involve elements of novelty, uncertainty, and unpredictability. This has been highlighted by the observation that anticipating an event can be as potent an activator of the stress response as the event itself (7).

scholarly journals The role of carbon dioxide in nematode behaviour and physiology

Parasitology ◽  
2019 ◽  
Vol 147 (8) ◽  
pp. 841-854 ◽  
Author(s):  
Navonil Banerjee ◽  
Elissa A. Hallem
Keyword(s):  
Carbon Dioxide ◽  
Neural Circuit ◽  
Physiological Responses ◽  
Life Stage ◽  
Free Living ◽  
Behavioural Responses ◽  
Wide Range ◽  
Sensory Cue ◽  
Context Dependent

AbstractCarbon dioxide (CO2) is an important sensory cue for many animals, including both parasitic and free-living nematodes. Many nematodes show context-dependent, experience-dependent and/or life-stage-dependent behavioural responses to CO2, suggesting that CO2 plays crucial roles throughout the nematode life cycle in multiple ethological contexts. Nematodes also show a wide range of physiological responses to CO2. Here, we review the diverse responses of parasitic and free-living nematodes to CO2. We also discuss the molecular, cellular and neural circuit mechanisms that mediate CO2 detection in nematodes, and that drive context-dependent and experience-dependent responses of nematodes to CO2.

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