No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
The effect of anthropogenic noise on foraging and vigilance in zoo-housed pied-tamarins
Abstract
The phenomenon of human-induced rapid environmental change (HIREC) is a great challenge in the modern world that presents a threat to all species. Research on the effect of anthropogenic noise on free-living wildlife is increasing but the effect of anthropogenic noise on the behaviour and welfare of captive wildlife has received limited attention, even though captive settings are full of human activity and a wide range of sounds. Moreover, studies in captivity tend to classify noise subjectively by volume according to human hearing, and as part of the overall ‘visitor effect’ rather than a stressor in its own right. Research on free-living wildlife suggests that anthropogenic noise can negatively impact foraging behaviour; similar impacts in captive species could have a detrimental effect on their health and welfare if animals cannot perform functional feeding behaviours and access adequate nutrition. In the current study, we designed a forage box experiment for captive pied tamarins, a Critically Endangered callitrichid primate species that is prone to poor physical health and breeding success in captivity. Ten pairs of tamarins housed at Jersey Zoo were provided with a forage box containing cryptic (hidden) prey items (waxworms). Using a within-subjects design, tamarins were provided access to the forage box in noise and non-noise conditions of anthropogenic noise (machinery used for gardening in the zoo). Both active (foraging with the hands) and observational (looking into the forage box) foraging were significantly less frequent in the presence of anthropogenic noise; however, there was no difference in the duration of these behaviours or in foraging success. Furthermore, the presence of anthropogenic noise did not significantly affect vigilance behaviour. We found no sex differences in the effect of noise, and our results suggest that the anthropogenic noise we tested was only a minimal distractor for tamarins. However, large individual differences in foraging suggest that other factors may have a larger impact on foraging than the anthropogenic noise used in this experiment. More research into how captive animals may respond to the presence of anthropogenic noise is needed.
... Events happen immediately and then normally estimated by the frequency, whereas states last for a sizable portion of time and are estimated by the duration of time spent on a given activity Altmann, 1974). We chose to document both estimates of behavior to fully grasp the impact of visitors (Steinbrecher et al., 2023). In the present study, we tested whether the number of visitors, visitor's presence duration, and climatic factors influence the behavior of these caged female pheasants. ...
... Consequently, during the course of our research, the data represent observations of five birds in total. From the continuous recordings, we extracted six behavior estimates: feeding events, feeding duration, hiding events, moving events, and moving duration with 35 h per day and a total of 525 h (Steinbrecher et al., 2023). Our cameras record videos that last for 1 min. ...
... We counted the events of each behavior per hour before statistical analyses. We also used the sum of the total time duration of each behavior per hour for analysis (Steinbrecher et al., 2023). Environmental variables including hourly temperature and relative humidity were collected from the weather station of the city. ...
Background
The interaction between visitors and captive birds is complex, with a potential impact on bird’s behavior and welfare. Understanding this interaction is essential for effective conservation and management.
Methods
We conducted a study at the University of Haripur’s pheasantry in Khyber Pakhtunkhwa, Pakistan to investigate the effects of visitor numbers, duration of visitor presence, and climatic factors on the behavior of female pheasants. We observed the state and events of feeding, hiding, and moving behaviors of 16 randomly selected individuals from five species.
Results
The mixed-effects modeling results show that visitors (VT), visitors’ presence duration (VPD), and temperature (TP), significantly influence feeding events ( p < 0.001), feeding duration ( p < 0.001), hiding events ( p < 0.001) and hiding duration of female pheasants ( p < 0.001). The moving events of pheasants were also significantly affected by both VT and VPD (VT: p = 0.002, VPD: p < 0.001). Moreover, under high visitor conditions, the impact of VPD on the behavior of female pheasants was more pronounced ( p < 0.001). Additionally, our result reveals that different species of pheasants exhibit varying sensitivities to human factors and climatic factors. For instance, the two species of female pheasants with the highest feeding and hiding events were the Green pheasant ( Phasianus versicolor ) and the Ring-necked pheasant ( Phasianus colchicus ). While hiding duration of female Green pheasants, female Golden pheasants ( Chrysolophus pictus ), and female Silver pheasants ( Lophura nycthemera ) was longer than those of others. The mean number of moving events was highest in females of Ring-necked, followed by Golden pheasants. The female Indian peafowl ( Pavo cristatus ) and female Silver pheasants were the birds with the longest moving duration.
Conclusion
Our findings highlight the necessity for customized management strategies, to lessen the effects of human disturbances in pheasantries. For a thorough understanding of these interactions, more studies involving larger sample sizes and a wider variety of species are advised.
... Increased environmental noise in zoos has been repeatedly shown to impact zoo animal behavior and welfare across many species. For example, as visitor noise levels increased, koalas increased vigilance behavior (Larsen et al., 2014), multiple bird species in a free flight aviary stayed further from the visitor pathway (Blanchett et al., 2020), and tamarins showed decreased foraging activity (Steinbrecher et al., 2023). These changes in behavior suggest that these animals find visitor noise levels to be aversive (Quadros et al., 2014). ...
Zoo visitors constitute a major part of a zoo animal’s environment and can have measurable impacts on their behavior and welfare, a phenomenon referred to as the visitor effect. The influence of visitors on animal welfare is generally categorized as positive, neutral, or negative, with most, but not all, studies reporting a negative or neutral relationship. However, most studies on visitor effects have been conducted with mammals, and therefore more research is needed to understand how zoo animals of other taxonomic groups, such as reptiles, are impacted by zoo visitors. At Lincoln Park Zoo (Chicago, IL, USA), a semi-aquatic turtle enclosure is located indoors next to a large children’s play structure. This indoor environment can become busy and loud during peak hours, which could impact the turtles’ welfare. To assess whether the turtles are collectively impacted by visitors, we recorded the turtles’ space use within their enclosure with changing visitor presence and visitor activity. We found no evidence that the turtles’ visibility or their propensity to seek coverage was affected by visitor presence or visitor activity. However, our data indicates that the turtles tended to be further from the visitor viewing glass as the number of people on the play structure increased and as visitor noise level increased. The other environmental variables measured -- crowd size in front of the turtle enclosure and tapping on the visitor viewing glass – did not significantly impact turtle space use.
... feeding and vigilance behavior (Steinbrecher et al. 2023), little is known about the impact of 153 noise on pied tamarin vocal behavior in the wild. 154 The current study aimed to evaluate whether pied tamarins alter their communication 155 behavior in response to urban noise. ...
... They are emitted during inter-and intragroup interactions, such as territorial defense, group movement, and cohesion (Sobroza et al., 2017. While noise levels in captivity are known to have a low impact on pied tamarins feeding and vigilance behavior (Steinbrecher et al., 2023), little is known about the impact of noise on pied tamarin vocal behavior in the wild. ...
Many animal species depend on sound to communicate with conspecifics. However, human‐generated (anthropogenic) noise may mask acoustic signals and so disrupt behavior. Animals may use various strategies to circumvent this, including shifts in the timing of vocal activity and changes to the acoustic parameters of their calls. We tested whether pied tamarins ( Saguinus bicolor ) adjust their vocal behavior in response to city noise. We predicted that both the probability of occurrence and the number of long calls would increase in response to anthropogenic noise and that pied tamarins would temporally shift their vocal activity to avoid noisier periods. At a finer scale, we anticipated that the temporal parameters of tamarin calls (e.g., call duration and syllable repetition rate) would increase with noise amplitude. We collected information on the acoustic environment and the emission of long calls in nine wild pied tamarin groups in Manaus, Brazil. We found that the probability of long‐call occurrence increased with higher levels of anthropogenic noise, though the number of long calls did not. The number of long calls was related to the time of day and the distance from home range borders—a proxy for the distance to neighboring groups. Neither long‐call occurrence nor call rate was related to noise levels at different times of day. We found that pied tamarins decreased their syllable repetition rate in response to anthropogenic noise. Long calls are important for group cohesion and intergroup communication. Thus, it is possible that the tamarins emit one long call with lower syllable repetition, which might facilitate signal reception. The occurrence and quantity of pied tamarin' long calls, as well as their acoustic proprieties, seem to be governed by anthropogenic noise, time of the day, and social mechanisms such as proximity to neighboring groups.
... Finally, whilst we find an effect of human presence on the soundscape, we did not investigate whether these differences impacted animals' biology. Changes in the sound environment may result in shifts in behaviour, such as altered activity budgets (e.g., Steinbrecher et al., 2023)) or enclosure usage (e.g. Wark et al., 2023), or physiological changes (e.g., Powell et al., 2006). ...
Natural environmental conditions are often overlooked in the welfare evaluation of captive animals despite their significant impact. However, numerous studies have shown how factors such as temperature and relative humidity influence the behaviour of wild avian species, leading to reduced foraging, locomotion and increased call rates. Additionally, anthropogenic factors, such as noise, have been shown to affect the behaviour of captive birds as well. All the birds were relocated from Jurong Bird Park, Singapore, to the newly established Bird Paradise, Singapore. The aim of this study was to observe the behavioural responses of five hornbill species: great hornbill (Buceros bicornis), rhinoceros hornbill (Buceros rhinoceros), wreathed hornbill (Rhyticeros undulatus), black-casqued hornbill (Ceratogymna atrata), and crowned horn-bill (Lophoceros alboterminatus) to noise, ambient temperature and relative humidity. The sound pressure levels (SPL), temperature, and relative humidity levels were measured, and the behaviour of nine individual hornbills was observed using an ethogram four times a day with 15-min sessions over one month. The results showed (1) the hornbills were significantly more active when noise increased and significantly less active when temperature increased; (2) there was a significant increase in resting in the hornbills as temperature rose and a significant decrease in resting when noise increased; (3) as humidity increased, the hornbills displayed significantly more self-maintenance behaviours. Noise was found to have a greater impact on active and resting behaviour than temperature. While anthropogenic influences do affect animal behaviour, natural environmental factors are often overlooked and should be incorporated into a comprehensive evaluation of animal welfare.
Sound is a complex feature of all environments, but captive animals' soundscapes (acoustic scenes) have been studied far less than those of wild animals. Furthermore, research across farms, laboratories, pet shelters, and zoos tends to focus on just one aspect of environmental sound measurement: its pressure level or intensity (in decibels). We review the state of the art of captive animal acoustic research and contrast this to the wild, highlighting new opportunities for the former to learn from the latter. We begin with a primer on sound, aimed at captive researchers and animal caregivers with an interest (rather than specific expertise) in acoustics. Then, we summarize animal acoustic research broadly split into measuring sound from animals, or their environment. We guide readers from soundwave to soundscape and through the burgeoning field of conservation technology, which offers new methods to capture multiple features of complex, gestalt soundscapes. Our review ends with suggestions for future research, and a practical guide to sound measurement in captive environments.
Studies of personality traits in common marmosets (Callithrix jacchus) indicate that there are five or six constructs—Sociability, Dominance, Neuroticism, Openness, and two related to Conscientiousness. The present study attempted to determine whether our earlier study of laboratory-housed individuals only yielded three—Dominance, Sociability, and Neuroticism—because of a low amount of between-subjects variance. To do so, we increased our sample size from 77 to 128. In addition, we ascertained the reliability and validity of ratings and whether polymorphisms related to the serotonin 1a receptor were associated with personality. We found Sociability, Dominance, and Negative Affect factors that resembled three domains found in previous studies, including ours. We also found an Openness and Impulsiveness factor, the latter of which bore some resemblance to Conscientiousness, and two higher-order factors, Pro-sociality and Boldness. In further analyses, we could not exclude the possibility that Pro-sociality and Boldness represented a higher-level of personality organization. Correlations between personality factors and well-being were consistent with the definitions of the factors. There were no significant associations between personality and genotype. These results suggest that common marmoset personality structure varies as a function of rearing or housing variables that have not yet been investigated systematically.
Background
Chronic recurrent diarrhoea and weight loss is a common problem in captive callitrichids. These symptoms are common clinical features of marmoset wasting syndrome (MWS), a chronic enteric inflammation of unknown aetiology associated with mortality in captive marmosets. The unknown aetiology of the condition presents problems for conservation projects where affected colonies present higher mortality and lower birth rates. Since a role for the microbiome has been established in chronic enteric inflammation of other species it is possible that the intestinal microbiome undergoes similar changes during MWS.
Results
The faecal microbiome of pied tamarins ( Saguinus bicolor ) at Jersey Zoo was determined using 16S rRNA gene amplicon sequencing to compare the composition of the faecal microbiome of tamarins affected by chronic recurrent diarrhoea and weight loss with unaffected individuals. Affected individuals had a higher relative abundance of amplicon sequence variants assigned to Lactobacillus and Helicobacter jaachi while unaffected individuals had a higher relative abundance of some Lachnospiraceae and Ruminococcaceae .
Conclusions
Although Helicobacter has been shown to reside in healthy wild and captive marmosets and tamarins and appears to form part of the normal microbiota, the results of this study raise the prospect that certain species of Helicobacter may be associated with chronic, recurrent diarrhoea in captive callitrichids. The presence of Lactobacillus may also play a role in the development of MWS. Since depletion of Lachnospiraceae and Ruminococcaceae have been linked to chronic gastrointestinal inflammation in humans, this feature of the microbiome of affected tamarins provides another avenue of further research in the pathogenesis of MWS.
A new framework for animal-behaviour research will help to avoid sampling bias — ten years on from the call to widen the pool of human participants in psychology studies beyond the WEIRD. A new framework for animal-behaviour research will help to avoid sampling bias — ten years on from the call to widen the pool of human participants in psychology studies beyond the WEIRD.
One way to address questions about the origins and adaptive significance of personality dimensions is by comparing the personality structures of closely related species that differ in their socioecological circumstances. For the present study, we compared the personalities of captive golden-handed tamarins (Saguinus midas; N = 28), cotton-top tamarins (Saguinus oedipus; N = 20), and common marmosets (Callithrix jacchus; N = 17). All 3 species are New World monkeys of the family Callitrichidae. They thus share reproductive and behavioral characteristics but differ some in terms of their diet, habitat, and social organization. We expected that personality structures of closely related tamarin species would overlap more, both in terms of number of dimensions and their content, than either would overlap with the personality structure of common marmosets. We assessed personality using behavioral observations and compared the personality structures by means of cross-species correlations and fuzzy set analyses. Principal component analyses identified components that we labeled Agreeableness, Assertiveness, and Extraversion in golden-handed tamarins and common marmosets and components labeled Confidence and Extraversion in cotton-top tamarins. The greater personality similarities of the two phylogenetically more distant species suggest that differences in social organization, and in both habitat diversity and complexity, contributed to the evolution of personality. However, we also found that behaviors clustered in similar ways in the two tamarin species, suggesting that phylogenetic relatedness and genus-specific socioecological characteristics, such as the degree of reproductive competition, shaped personality structure in this primate family. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
A “visitor effect” on zoo-housed species has been documented since the 1970s, with research focused on mammals (specifically primates). To broaden our understanding of the “visitor effect” in a non-mammal, we conducted a case study on a pair of hornbills, recording behavior and aviary use alongside of visitor and keeper presence. Temperature and humidity were significant predictors of visitor number, and temperature was a better predictor of hornbill exhibit use than visitor presence. Behavior was significantly affected by the presence of keepers and individual variation in behavior was noted too. Visitor number mediated any interest in a keeper by birds: high visitor number decreased a bird's interest in its keeper. Whilst only a case study on a pair of birds, our research shows that any “visitor effect” is heavily influenced by other environmental variables and that different categories of human (i.e., visitor, keeper) affect how zoo animals utilize their environment.
Increasing levels of road noise are creating new anthropogenic soundscapes that may affect wildlife globally. Bats, which form about a third of all mammal species, are sensitive bioindicators, and may be particularly vulnerable because of their dependency on echolocation. However, few studies have solely focused on this potential impact, with many suggesting its influence when examining roads as a whole but cannot differentiate its effects, and as such what can be done to mitigate it. Here we present the first controlled field experiment with free-living bats, using a Before-After-Control-Impact phantom road experimental design, to examine the impacts of traffic noise on their activity and feeding behaviour, separately. Disentangling the impacts of traffic noise from other co-varying exposures such as habitat quality; demonstrating a significant negative effect on bat activity for each of the five ecologically different species groups examined. Thus, suggesting that the results are general and wide spread. This negative effect was almost wholly found to be due to the sonic spectrum of traffic noise, which elicited aversive responses in all bat species tested. Whereas, responses to ultrasonic noise were restricted to a single species. Our findings demonstrate that traffic noise can affect bat activity at least 20m away from the noise source. In addition, our results highlight that traffic noise not only negatively influences the activity of Pipistrellus pipistrellus and Pipistrellus pygmaeus, but also affects their feeding behaviour. We demonstrates the type of impact traffic noise can have on bat assemblages, signifying that Ecological Impact Assessments are needed wherever there are significant increases in traffic flow, and not just when new roads are built. Further research is required to identify effective mitigation strategies, the full extent of road-effect zones, and to assess whether there is any habituation over time.
Anthropogenic noise is an emergent ecological pollutant in both terrestrial and aquatic habitats. Human population growth, urbanisation, resource extraction, transport and motorised recreation lead to elevated noise that affects animal behaviour and physiology, impacting individual fitness. Currently, we have a poor mechanistic understanding of the effects of anthropogenic noise, but a likely candidate is the neuroendocrine system that integrates information about environmental stressors to produce regulatory hormones; glucocorticoids (GCs) and androgens enable rapid individual phenotypic adjustments that can increase survival. Here, we carried out two field-based experiments to investigate the effects of short-term (30 min) and longer-term (48 h) motorboat-noise playback on the behaviour, GCs (cortisol) and androgens of site-attached free-living orange-fin anemonefish (Amphiprion chrysopterus). In the short-term, anemonefish exposed to motorboat-noise playback showed both behavioural and hormonal responses: hiding and aggression increased, and distance moved out of the anemone decreased in both sexes; there were no effects on cortisol levels, but male androgen levels (11-ketotestosterone and testosterone) increased. Some behaviours showed carry-over effects from motorboat noise after it had ceased, and there was no evidence for a short-term change in response to subsequent motorboat-noise playback. Similarly, there was no evidence that longer-term exposure led to changes in response: motorboat noise had an equivalent effect on anemonefish behaviour and hormones after 48 h as on first exposure. Longer-term noise exposure led to higher levels of cortisol in both sexes and higher testosterone levels in males, and stress-responses to an additional environmental challenge in both sexes were impaired. Circulating androgen levels correlated with aggression, while cortisol levels correlated with hiding, demonstrating in a wild population that androgen/glucocorticoid pathways are plausible proximate mechanisms driving behavioural responses to anthropogenic noise. Combining functional and mechanistic studies are crucial for a full understanding of this global pollutant.
Anthropogenic noise has become a major global pollutant and studies have shown that noise can affect animals. However, such single studies cannot provide holistic quantitative assessments on the potential effects of noise across species. Using a multi-level phylogenetically controlled meta-analysis, we provide the first holistic quantitative analysis on the effects of anthropogenic noise. We found that noise affects many species of amphibians, arthropods, birds, fish mammals, molluscs and reptilians. Interestingly, phylogeny contributes only little to the variation in response to noise. Thus, the effects of anthropogenic noise can be explained by the majority of species responding to noise rather than a few species being particularly sensitive to noise. Consequently, anthropogenic noise must be considered as a serious form of environmental change and pollution as it affects both aquatic and terrestrial species. Our analyses provide the quantitative evidence necessary for legislative bodies to regulate this environmental stressor more effectively.
Many animals respond well behaviorally to stimuli associated with human-induced rapid environmental change (HIREC), such as novel predators or food sources. Yet others make errors and succumb to evolutionary traps: approaching or even preferring low quality, dangerous or toxic options, avoiding beneficial stimuli, or wasting resources responding to stimuli with neutral payoffs. A common expectation is that learning should help animals adjust to HIREC; however, learning is not always expected or even favored in many scenarios that expose animals to ecological and evolutionary traps. We propose a conceptual framework that aims to explain variation in when learning can help animals avoid and escape traps caused by HIREC. We first clarify why learning to correct two main types of errors (avoiding beneficial options and approaching detrimental options) might be difficult (limited by constraints). We then identify and discuss several key behavioral mechanisms (adaptive sampling, generalization, habituation, reversal learning) that can be targeted to help animals learn to avoid traps. Finally, we discuss how individual differences in neophobia/neophilia and personality relate to learning in the context of HIREC traps, and offer some general guidance for disarming traps. Given how devastating traps can be for animal populations, any breakthrough in mitigating trap outcomes via learning could make the difference in developing effective solutions.
Anthropogenic noise is a recognized global pollutant, affecting a wide range of nonhuman animals. However, most research considers only whether noise pollution has an impact, ignoring that individuals within a species or population exhibit substantial variation in responses to stress. Here, we first outline how intrinsic characteristics (e.g., body size, condition, sex, and personality) and extrinsic factors (e.g., environmental context, repeated exposure, prior experience, and multiple stressors) can affect responses to environmental stressors. We then present the results of a systematic search of the anthropogenic-noise literature, identifying articles that investigated intraspecific variation in the responses of nonhuman animals to noise. This reveals that fewer than 10% of articles (51 of 589) examining impacts of noise test experimentally for intraspecific variation in responses; of those that do, more than 75% report significant effects. We assess these existing studies to determine the current scope of research and findings to-date, and to provide suggestions for good practice in the design, implementation, and reporting of robust experiments in this field. We close by explaining how understanding intraspecific variation in responses to anthropogenic noise is crucial for improving how we manage captive animals, monitor wild populations, model species responses, and mitigate effects of noise pollution on wildlife. Our aim is to stimulate greater knowledge and more effective management of the harmful consequences of this global pollutant.
Simple Summary
Research has shown that an animal’s welfare is highly dependent on how various individual animal factors (e.g., species traits, genetics, temperament and previous experience) interact with environmental features (e.g., social grouping, enclosure design and sensory environment). One prominent feature of a zoo’s environment is the presence of visitors. Decades of research on the visitor effect in zoos has demonstrated that visitors can have negative, neutral or positive impacts on zoo animal behaviour and welfare. This paper reviews the literature on the implications and potential opportunities of human–zoo animal interactions on animal behaviour and welfare, with the aim of stimulating interest, understanding and exploration of this important subject.
Abstract
Achieving and maintaining high standards of animal welfare is critical to the success of a modern zoo. Research has shown that an animal’s welfare is highly dependent on how various individual animal factors (e.g., species traits, genetics, temperament and previous experience) interact with environmental features (e.g., social grouping, enclosure design and sensory environment). One prominent feature of the zoo environment is the presence of visitors. Visitor contact can be unpredictable and intense, particularly in terms of auditory and visual interaction. Depending on an animal’s perception of this interaction, visitors can have either negative, neutral or positive impacts on zoo animal behaviour and welfare. This paper reviews the literature on the implications and potential opportunities of human-zoo animal interactions on animal behaviour and welfare, with the aim of stimulating interest, understanding and exploration of this important subject. The literature to date presents a mixed range of findings on the topic. It is possible this variation in the responses of zoo animals to visitors may be due to species-specific differences, the nature and intensity of the visitor interactions, enclosure design, and individual animal characteristics. Analysing these studies and better understanding animal preferences and motivations can provide insight into what animals find negatively and positively reinforcing in terms of visitor contact in a specific zoo setting. This understanding can then be applied to either safeguard welfare in cases where visitors can have a negative impact, or, conversely, it can be applied to highlight opportunities to encourage animal-visitor interaction in situations where animals experience positive emotions associated with visitor interaction.
Ambient noise can affect the availability of acoustic information to animals, altering both foraging and vigilance behaviour. Using captive zebra finches Taeniopygia guttata, we examined the effect of ambient broadband noise on foraging decisions. Birds were given a choice between foraging in a quiet area where conspecific calls could be heard or a noisy area where these calls would be masked. Birds foraging in noisy areas spent a significantly more time vigilant than those in quiet areas, resulting in less efficient foraging. Despite this there was no significant difference in the amount of time spent in the two noise regimes. However there did appear a preference for initially choosing quiet patches during individuals’ second trial. These results emphasise how masking noise can influence the foraging and anti-predation behaviour of animals, which is particularly relevant as anthropogenic noise becomes increasingly prevalent in the natural world.
Peri-urban expansion is an increasingly important source of tropical deforestation, and a bridge over the Rio Negro in Brazil’s state of Amazonas provides an unusual opportunity to quantify these impacts with clear “before” and “after” periods. Inaugurated in 2011, the bridge connects Manaus to forest areas on the right bank of the river, thus opening a new frontier for peri-urban expansion. We used the AGROECO model in the Dinamica-EGO software to simulate “Bridge” and “No-bridge” scenarios to evaluate the spatial dynamics of deforestation in the municipalities (counties) of Iranduba, Manacapuru and Novo Airão. Simulated deforestation between 2011 and 2030 for the study area as a whole was 106% higher with the bridge. The portion of the study area with expansion of roads had four times more deforestation in the Bridge scenario than in the No-bridge scenario. A change in the spatial distribution of the deforested area was detected, with an advance of deforestation in the municipality closest to the bridge. Deforestation also expanded in more distant regions. Peri-urbanization in the Bridge scenario demonstrates the possible increase in the spatial distribution of deforestation activity beyond the already-consolidated frontier, making the deforestation pattern more diffuse and leaving the remaining forest even more vulnerable. Impact of the bridge could further increase due to additional factors, such as the planned opening of a highway (BR-319) connecting Manaus to Brazil’s “arc of deforestation.”
In this study, we tested the hypothesis that individual differences in behavioural profiles correlate to differences in stress-related behaviours and hormonal levels in captive brown capuchin monkeys (Sapajus libidinosus). Based on a sample of 25 animals, 143 h of behavioural data collection and 518 faecal samples, principal component analyses indicated the existence of four components that characterize the individuals´ Genus Normative Behaviour (GNB) (KMO = 0.531, X² = 127.672, p < 0.001): ‘Feeding’ ‘Sociability’ ‘Exploration’ and ‘Activity’. Other four components are related to stress coping styles (based on Behaviour Potentially Indicative of Stress – BPIS) (KMO = 0.550, X² = 329.303, p < 0.001): ‘Self-directed’; ‘Restless’ ‘Ingestion/Self-Scratching’ and ‘Stereotyped’. More active individuals exhibit rapid stress-related behaviours (r = 0.443; p = 0.044) while less active individuals exhibit more stationary stress-related behaviours (r = -0.519; p = 0.013). Akaike information criteria indicated that the best linear regression model to predict the physiological profile (Faecal Glucocorticoid Metabolites - FGM) included three GNB and three BPIS components. ‘Sociability’ (p < 0.05), ‘Exploration’ (p < 0.05), and ‘Ingestion/Self-scratching’ (p < 0.05) predicted lower FGM levels. ‘Activity’ (p < 0.05), ‘Self-directed’ (p < 0.05), and ‘Stereotyped’ (p < 0.05) predicted higher FGM levels. ‘Feeding’ and ‘Restless’ factors were not included in the models. Our results support previous studies indicating that animals within the same population differ in the way they behave and react to stressful conditions, and these are correlated to different physiological profiles. Mapping inter-individual differences in stress coping strategies may help clarify the long-term reported incongruity between behavioural and physiological indicators of welfare in captive animals, supporting better management practices and assisting translational models of the development of psychopathologies.
We studied personality, subjective well-being, and hair cortisol level, in common marmosets Callithrix jacchus, a small, cooperatively breeding New World monkey, by examining their associations with one another and genotypes. Subjects were 68 males and 9 females that lived in the RIKEN Center for Life Science Technologies. Personality and subjective well-being were assessed by keeper ratings on two questionnaires, hair samples were obtained to assay cortisol level and buccal swabs were used to assess AVPR1a, OPRM1 and DAT genotypes. Three personality domains-Dominance, Sociability, and Neuroticism-were identified. Consistent with findings in other species, Sociability and Neuroticism were related to higher and lower subjective well-being, respectively. Sociability was also associated with higher hair cortisol levels. The personality domains and hair cortisol levels were heritable and associated with genotypes: the short form of AVPR1a was associated with lower Neuroticism and the AA genotype of the A111T SNP of OPRM1 was related to lower Dominance, lower Neuroticism, and higher hair cortisol level. Some genetic associations were not in directions that one would expect given findings in other species. These findings provide insights into the proximate and ultimate bases of personality in common marmosets, other primates and humans.
The use of linear mixed effects models (LMMs) is increasingly common in the analysis of biological data. Whilst LMMs offer a flexible approach to modelling a broad range of data types, ecological data are often complex and require complex model structures, and the fitting and interpretation of such models is not always straightforward. The ability to achieve robust biological inference requires that practitioners know how and when to apply these tools. Here, we provide a general overview of current methods for the application of LMMs to biological data, and highlight the typical pitfalls that can be encountered in the statistical modelling process. We tackle several issues regarding methods of model selection, with particular reference to the use of information theory and multi-model inference in ecology. We offer practical solutions and direct the reader to key references that provide further technical detail for those seeking a deeper understanding. This overview should serve as a widely accessible code of best practice for applying LMMs to complex biological problems and model structures, and in doing so improve the robustness of conclusions drawn from studies investigating ecological and evolutionary questions.
In the zoo environment, anthropogenic noise is common as sound levels fluctuate due to visitors, construction, habitat design, and special events. In this study, changes in the mood of three species of zoo-housed primates in response to a loud annual event were evaluated with the response-slowing paradigm. In this paradigm, animals experiencing anxiety slow responses on simple cognitive tasks when emotional content is displayed. Following a previously validated approach, we measured latencies to touch potentially threatening (conspecific faces with directed gaze) and non-threatening (conspecific faces with averted gaze) images overlaid on a grey square, relative to neutral control images (grey squares only) on a touchscreen. In Experiment 1, four Japanese macaques (Macaca fuscata) were tested in two conditions: during a baseline (non-stressful) period and opportunistically during three days during which loud jets frequently flew overhead. Results indicated a significant effect of condition, with an increase in latency to touch images of conspecific faces relative to control images during the days of the loud event. In Experiment 2, chimpanzees (Pan troglodytes, n = 4) and western lowland gorillas (Gorilla gorilla gorilla, n = 2) were tested during the same loud event following a similar methodology. The results revealed subtle changes across conditions; however, this was likely driven by the apes increasing their response speed to face stimuli relative to control stimuli over time (habituation). These findings suggest that the macaques, but not the apes, underwent detectable affective changes during the loud event. With additional development, this relatively simple paradigm may be an effective and feasible way to evaluate real-time changes in the mood of zoo-housed animals.
Noise pollution is a major problem in cities around the world. Noise is defined as unwanted sound. Environmental noise consists of all the unwanted sounds in our communities except that which originates in the workplace. Environmental noise pollution, a form of air pollution, is a threat to health and well-being. It is more severe and widespread than ever before, and it will continue to increase in magnitude and severity because of population growth, urbanization, and the associated growth in the use of increasingly powerful, varied, and highly mobile sources of noise. It will also continue to grow because of sustained growth in highway, rail, and air traffic, which remain major sources of environmental noise. In factory workplace workers are exposed to high noise due to machinery in routine. The potential health effects of noise pollution are numerous, pervasive, persistent, medically and socially significant. Noise produces direct and cumulative adverse effects that impair health and that degrade residential, social and working environment with corresponding real (economic) and intangible (well-being) losses. Noise represents an important public health problem that can lead to hearing loss, sleep disruption, cardiovascular disease, social handicaps, reduced productivity, negative social behaviour, annoyance reactions, absenteeism and accidents. It can impair the ability to enjoy one's property and leisure time and increases the frequency of antisocial behaviour. Noise adversely affects general health and well-being in the same way as does chronic stress. It adversely affects future generations by degrading residential, social, and learning environments with corresponding economic losses. The aim of enlightened governmental controls should be to protect citizens from the adverse effects of airborne pollution, including those produced by noise. People have the right to choose the nature of their acoustical environment; it should not be imposed by others.
The study of animal sound signals can be useful in assisting conservation strategies. Understanding the vocal repertoires of endangered species and the behavioral contexts in which they are given is relevant for monitoring protocols, such as those based on automated sound recordings. The pied tamarin (Saguinus bicolor) is at risk of extinction because of deforestation and urban growth in its restricted geographic range. Between 2012 and 2015 we studied the vocal repertoire of the species and the contexts in which different signals are emitted. We made focal recordings of eight free-living groups, two rescued individuals, and one temporarily captive group of pied tamarins in Manaus, central Brazilian Amazonia. From the 766 sounds analyzed we identified 12 distinct signals within the range of 2–11 kHz. Most signals were emitted during resting or locomotion. Less frequently emitted signals were associated with intergroup agonistic interactions, foraging, and infant-exclusive vocalizations. These results increased the known vocal repertoire of the pied tamarin providing more reliable baseline data for monitoring the species by means of automated or focal sound recordings.
Anthropogenic noise has been increasing globally. Laboratory experiments suggest that noise disrupts foraging behavior across a range of species, but to reveal the full impacts of noise, we must examine the impacts of noise on foraging behavior among species in the wild. Owls are widespread nocturnal top predators and use prey rustling sounds for localizing prey when hunting. We conducted field experiments to examine the effect of traffic noise on owls' ability to detect prey. Results suggest that foraging efficiency declines with increasing traffic noise levels due to acoustic masking and/or distraction and aversion to traffic noise. Moreover, we estimate that effects of traffic noise on owls' ability to detect prey reach >120 m from a road, which is larger than the distance estimated from captive studies with bats. Our study provides the first evidence that noise reduces foraging efficiency in wild animals, and highlights the possible pervasive impacts of noise.
ABSTRACT: Diverse biological consequences of noise exposure are documented by an extensive literature. Unfortunately, the aggregate value of this literature is compromised by inconsistencies in noise measurements and incomplete descriptions of metrics. These studies commonly report the noise level (in decibels, dB) at which a response was measured. There are many methods to characterize noise levels in dB, which can result in different values depending on the processing steps used. It is crucial that methods used for noise level measurement be reported in sufficient detail to permit replication and maximize interpretation of results, enable comparisons across studies, and provide rigorous foundations for noise management in environmental conservation. Understanding the differences in the acoustic measurements is vital when making decisions about acceptable levels or thresholds for conservation strategies, particularly for endangered species where mistakes can have irreversible consequences. Here we provide a discussion on how different acoustic metrics are derived and recommendations on how to report sound level measurements. Examples of additional measures of noise besides level (e.g. spectral composition, duration) are discussed in the context of providing further insight on the consequences of noise and will potentially help develop effective mitigation. It will never be possible to study all combinations of sources and species. Standardized methods of noise measurement and reporting are necessary to advance syntheses and general models that predict the ecological consequences of noise.
Quantitative aspects of the study of animal and human behaviour are increasingly relevant to test hypotheses and find empirical support for them. At the same time, photo and video cameras can store a large number of video recordings and are often used to monitor the subjects remotely. Researchers frequently face the need to code considerable quantities of video recordings with relatively flexible software, often constrained by species‐specific options or exact settings.
BORIS is a free, open‐source and multiplatform standalone program that allows a user‐specific coding environment to be set for a computer‐based review of previously recorded videos or live observations. Being open to user‐specific settings, the program allows a project‐based ethogram to be defined that can then be shared with collaborators, or can be imported or modified.
Projects created in BORIS can include a list of observations, and each observation may include one or two videos (e.g. simultaneous screening of visual stimuli and the subject being tested; recordings from different sides of an aquarium). Once the user has set an ethogram, including state or point events or both, coding can be performed using previously assigned keys on the computer keyboard. BORIS allows definition of an unlimited number of events (states/point events) and subjects.
Once the coding process is completed, the program can extract a time‐budget or single or grouped observations automatically and present an at‐a‐glance summary of the main behavioural features. The observation data and time‐budget analysis can be exported in many common formats ( TSV , CSV , ODF , XLS , SQL and JSON ). The observed events can be plotted and exported in various graphic formats ( SVG , PNG , JPG , TIFF , EPS and PDF ).
Metabolic bone disease (MBD) occasionally occurs in pied tamarins Saguinus bicolor at Jersey Zoo despite apparently appropriate dietary supplementation with vitamin D3. As an alternative approach to preventing MBD in this species, an ultraviolet B (UVB) lamp was fitted in the indoor enclosure of one family group. Blood levels of 25(OH)D3 and corneal and lens integrity were assessed in these tamarins, and in a control group supplemented with an extra 3,000 IU of vitamin D3/kg of food, to evaluate the efficacy of both treatments and the possible adverse effects of chronic exposure to artificial UVB radiation. No ocular damage was observed after 11 months, and the irradiated tamarins were able to produce significantly higher and more consistent levels of 25(OH)D3 than orally supplemented animals. These preliminary observations suggest that irradiation with artificial UVB light is likely to be safe for use in the health management of callitrichids and that, under the management conditions at Jersey Zoo, it may be a more reliable and efficient method of preventing MBD in pied tamarins than dietary supplementation.
An overview of the management, behaviour and reproduction of pied tamarins Saguinus bicolor bicolor at the Jersey Wildlife Preservation Trust from 1990-1996 is given. Breeding success has not been good; infant survival to one year is only 23.3%, and many infants have been killed by their parents. The successful hand-rearing and fostering of a rejected infant is described. Health has also been a problem, with three founding adults dying of various causes. Observations of seven male-female pairs showed that housing conditions influenced behaviour, and there were other indications that this species is more sensitive to environmental disturbance than other callitrichids. A further study suggested that pied tamarins respond adversely to the presence of zoo visitors. Changes to housing and management practices to reduce stress and improve nutrition are described, and further suggestions made to improve health and breeding success.
Anthropogenic noise is an emerging global pollutant. Road networks and energy extraction infrastructure are both spatially extensive and rapidly expanding sources of noise. We predict that predators reliant on acoustic cues for hunting are particularly sensitive to louder environments. Here we examined the foraging efficiency of pallid bats (Antrozous pallidus) when exposed to played-back traffic and gas compressor station noise in the laboratory. We show that both types of noise at each of five exposure levels (58–76 dBA, 10–640 m from source) and low-level amplifier noise (35 dBA) increase the time required for bats to locate prey-generated sounds by twofold to threefold. The mechanism underlying these findings is unclear and, given the potential landscape-level habitat degradation indicated by our data, we recommend continued research into the effects of noise exposure on acoustically specialized predators.
We analyzed DNA at 9 microsatellite loci from hair samples of 73 pied tamarins (Saguinus bicolor) located in 3 urban forest fragments and a biological reserve in the city of Manaus, Amazonas, Brazil. The forest fragments had become isolated from the continuous forest 6-15 years prior to the time of sampling. Tests for reduction in population size showed that all groups from the urban forest fragments had undergone genetic bottlenecks. Pied tamarins in this region historically formed one biological population, and the fragments were connected by high levels of gene flow. These results indicate the need to implement a conservation plan that allows for connectivity between the urban fragments, as well as protection from further constriction. Such connectivity could be achieved via the creation and protection of corridors. In addition to the current population trends explained by anthropogenic actions, the species also shows a trend of long-term demographic decline that has resulted in approximately an order of magnitude decrease and began 13 thousand years ago.
© The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
The study of personality in animals is a rapidly growing scientific field and numerous species have been reported to show consistent personality profiles. Much animal personality research has focused on nonhuman primates, with the main emphasis being placed on Old World primates, particularly rhesus macaques and chimpanzees. So far, little work has been done on cooperatively breeding nonhuman primates and New World species. Here, we study personality in the cooperatively breeding common marmosets (Callithrix jacchus) to broaden the taxonomic range of such research and to widen the perspective of comparative personality research. We use behavioral data collection and observer trait ratings to assess marmoset personality dimensions. The resulting behavioral and rating-derived personality dimensions, when viewed in tandem, resemble the human five-factor model and include extraversion, agreeableness, neuroticism, openness, and conscientiousness. Correlations between the behavioral data and the observer trait-rated personality components suggest that the personality construct of common marmosets exhibits both convergent and discriminant validity. The finding of a distinct Conscientiousness component in this species extends previous knowledge in comparative personality psychology and warrants reconsideration of proposed taxonomic trait distributions. (PsycINFO Database Record
(c) 2015 APA, all rights reserved).
The influence of human activity on the biosphere is increasing. While direct damage (e.g. habitat destruction) is relatively well understood, many activities affect wildlife in less apparent ways. Here we investigate how anthropogenic noise impairs foraging, which has direct consequences for animal survival and reproductive success. Noise can disturb foraging via several mechanisms that may operate simultaneously, and thus their effects could not be disentangled hitherto. We developed a diagnostic framework that can be applied to identify the potential mechanisms of disturbance in any species capable of detecting the noise. We tested this framework using Daubenton's bats, which find prey by echolocation. We found that traffic noise reduced foraging efficiency in most bats. Unexpectedly, this effect was present even if the playback noise did not overlap in frequency with the prey echoes. Neither overlapping nor non-overlapping noise influenced the search effort required for a successful prey capture. Hence, noise did not mask prey echoes or reduce the attention of bats. Instead, noise acted as an aversive stimulus that caused avoidance response, thereby reducing foraging efficiency. We conclude that conservation policies may seriously underestimate numbers of species affected and the multilevel effects on animal fitness, if the mechanisms of disturbance are not considered. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
The social environment influences animal personality on evolutionary and immediate time scales. However, studies of animal personality rarely assess the effects of the social environment, particularly in species that live in stable groups with individualized relationships. We assessed personality experimentally in 17 individuals of the common marmoset, living in four groups. We found their personality to be considerably modified by the social environment. Marmosets exhibited relatively high plasticity in their behaviour, and showed 'group-personality', i.e. group-level similarity in the personality traits. In exploratory behaviour this was maintained only in the social environment but not when individuals were tested alone, suggesting that exploration tendency is subjected to social facilitation. Boldness, in contrast, showed higher consistency across the social and solitary conditions, and the group-level similarity in trait scores was sustained also outside of the immediate social environment. The 'group-personality' was not due to genetic relatedness, supporting that it was produced by social effects. We hypothesize that 'group-personality' may be adaptive for highly cooperative animals through facilitating cooperation among individuals with similar behavioural tendency.
The influence of anthropogenic disturbance on the behavior of wild animals is increasingly-recognised for terrestrial systems. Data on free-ranging aquatic animals are comparatively scarce, and this represents a problem for estimating the consequences of human disturbance for organism fitness and therefore the functioning of aquatic systems. We used acoustic accelerometer and depth transmitters implanted in wild fish and archival stomach content data to test for relationships between the intensity of boating and the activity levels and foraging efficiency of an estuarine predatory fish, the mulloway Argyrosomus japonicus. Increasing boating activity (inferred from week-long trends in underwater noise and local maritime records) was associated with a reduction in activity levels and increased depth distributions of mulloway. Stomach content data from a nearby estuary revealed a far-lower feeding rate and altered diet composition on weekends (when boating activity is greatest) compared to weekdays for this species, and an inferred foraging success rate almost one-third that of weekdays. These data suggest the behavior and foraging intensity of mulloway is significantly influenced by anthropogenic disturbance. The overall fitness costs of the reduction in foraging success will depend on how readily mulloway can re-allocate foraging to less-disturbed conditions, and the extent of stress-related responses to disturbance in this species. This study supports earlier predictions that anthropogenic disturbances like noise could have significant impacts on the behavior and fitness of aquatic animals.
Nakagawa & Schielzeth extended the widely used goodness-of-fit statistic R2 to apply to generalized linear mixed models (GLMMs). However, their R2GLMM method is restricted to models with the simplest random effects structure, known as random intercepts models. It is not applicable to another common random effects structure, random slopes models.
I show that R2GLMM can be extended to random slopes models using a simple formula that is straightforward to implement in statistical software. This extension substantially widens the potential application of R2GLMM.
Maximum likelihood or restricted maximum likelihood (REML) estimates of the
parameters in linear mixed-effects models can be determined using the lmer
function in the lme4 package for R. As for most model-fitting functions in R,
the model is described in an lmer call by a formula, in this case including
both fixed- and random-effects terms. The formula and data together determine a
numerical representation of the model from which the profiled deviance or the
profiled REML criterion can be evaluated as a function of some of the model
parameters. The appropriate criterion is optimized, using one of the
constrained optimization functions in R, to provide the parameter estimates. We
describe the structure of the model, the steps in evaluating the profiled
deviance or REML criterion, and the structure of classes or types that
represents such a model. Sufficient detail is included to allow specialization
of these structures by users who wish to write functions to fit specialized
linear mixed models, such as models incorporating pedigrees or smoothing
splines, that are not easily expressible in the formula language used by lmer.
The behavior of wild, pelagic fish in response to sound playback was observed with a sonar/echo sounder. Schools of sprat Sprattus sprattus and mackerel Scomber scombrus were examined at a quiet coastal location. The fish were exposed to a short sequence of repeated impulsive sounds, simulating the strikes from a pile driver, at different sound pressure levels. The incidence of behavioral responses increased with increasing sound level. Sprat schools were more likely to disperse and mackerel schools more likely to change depth. The sound pressure levels to which the fish schools responded on 50% of presentations were 163.2 and 163.3 dB re 1 μPa peak-to-peak, and the single strike sound exposure levels were 135.0 and 142.0 dB re 1 μPa(2) s, for sprat and mackerel, respectively, estimated from dose response curves. For sounds leading to mackerel responses, particle velocity levels were also estimated. The method of observation by means of a sonar/echo sounder proved successful in examining the behavior of unrestrained fish exposed to different sound levels. The technique may allow further testing of the relationship between responsiveness, sound level, and sound characteristics for different types of man-made sound, for a variety of fish species under varied conditions.
Acoustic noise has the potential to cause stress, to distract and to mask important sounds, and thus to affect behaviour. Human activities have added considerable noise to both terrestrial and aquatic habitats, and there is growing evidence that anthropogenic noise affects communication and movement patterns in a variety of species. However, there has been relatively little work considering the effect on behaviours that are fundamental to survival, and thus have direct fitness consequences. We conducted a series of controlled tank-based experiments to consider how playback of ship noise, the most common source of underwater noise, affects foraging and antipredator behaviour in the shore crab, Carcinus maenas. Ship noise playback was more likely than ambient-noise playback to disrupt feeding, although crabs experiencing the two sound treatments did not differ in their likelihood of, or speed at, finding a food source in the first place. While crabs exposed to ship noise playback were just as likely as ambient-noise controls to detect and respond to a simulated predatory attack, they were slower to retreat to shelter. Ship noise playback also resulted in crabs that had been turned on their backs righting themselves faster than those experiencing ambient-noise playback; remaining immobile may reduce the likelihood of further predatory attention. Our findings therefore suggest that anthropogenic noise has the potential to increase the risks of starvation and predation, and showcases that the behaviour of invertebrates, and not just vertebrates, is susceptible to the impact of this pervasive global pollutant.
How do animals perceive the world, learn, remember, search for food or mates, communicate, and find their way around? Do any nonhuman animals count, imitate one another, use a language, or have a culture? What are the uses of cognition in nature and how might it have evolved? What is the current status of Darwin’s claim that other species share the same “mental powers” as humans, but to different degrees? In this completely revised second edition of Cognition, Evolution, and Behavior, Sara Shettleworth addresses these questions, among others, by integrating findings from psychology, behavioral ecology, and ethology in a unique and wide-ranging synthesis of theory and research on animal cognition, in the broadest sense--from species-specific adaptations of vision in fish and associative learning in rats to discussions of theory of mind in chimpanzees, dogs, and ravens. She reviews the latest research on topics such as episodic memory, metacognition, and cooperation and other-regarding behavior in animals, as well as recent theories about what makes human cognition unique. In every part of this new edition, Shettleworth incorporates findings and theoretical approaches that have emerged since the first edition was published in 1998. The chapters are now organized into three sections: Fundamental Mechanisms (perception, learning, categorization, memory), Physical Cognition (space, time, number, physical causation), and Social Cognition (social knowledge, social learning, communication). Shettleworth has also added new chapters on evolution and the brain and on numerical cognition, and a new chapter on physical causation that integrates theories of instrumental behavior with discussions of foraging, planning, and tool using.
Noise can be a known stressor but our understanding of its effects on animals living in zoo environments remains limited. Although exposure to loud, chronic noise may be expected to negatively impact welfare, providing access to quiet areas to escape loud noise may buffer these negative effects. In this study, we explored the benefits of access to quiet, off‐exhibit areas for animals living in a chronically loud sound environment. Two pied tamarins (Saguinus bicolor) living near a large waterfall feature that emitted loud, chronic noise were experimentally exposed to varying sound levels during 2‐week treatment conditions. Baseline conditions (waterfall feature on and access to quiet, off‐exhibit areas), were followed by a Quiet sound condition (waterfall off), a Loud sound condition (waterfall on and a speaker in the off‐exhibit area playing volume‐matched white noise), and a final Baseline condition. During Baseline conditions, sound levels were greater than 10 dBA higher in the exhibit than in the off‐exhibit area (i.e., roughly twice as loud). The number of visitor groups present during behavior observations were consistent throughout the study. Both tamarins modified their space use during treatment conditions. Under Baseline conditions, both individuals showed frequent usage of quiet, off‐exhibit areas. During the Quiet and Loud conditions, where sound levels were generally consistent across spaces, both individuals used off‐exhibit areas less and their use of exhibit and off‐exhibit areas was not significantly different than would be expected by chance, given the size of the areas. Additional behavioral changes were minimal. No significant differences in fecal glucocorticoid metabolites were observed. Although the monkeys in this study appeared to avoid noise, the overall impact on welfare appeared to be minimal considering the limited behavioral and hormonal changes observed. This study highlights the potential benefits of off‐exhibit spaces as a quiet refuge from noise in the zoo environment. Space use changes in two pied tamarins exposed to varying sound environments. Pied tamarins were experimentally exposed to loud, chronic white noise to evaluate the impact of sounds from a nearby waterfall feature. When given the choice, the tamarins appeared to avoid noise, but additional behavioral and physiological indicators of welfare were unchanged. This study highlights the potential benefits of access to quiet off‐exhibit spaces for zoo animals and the importance of considering space use as an indicator of welfare. Pied tamarins were experimentally exposed to loud, chronic white noise to evaluate the impact of sounds from a nearby waterfall feature. When given the choice, the tamarins appeared to avoid noise, but additional behavioral and physiological indicators of welfare were unchanged. This study highlights the potential benefits of access to quiet off‐exhibit spaces for zoo animals and the importance of considering space use as an indicator of welfare.
Noise pollution has spread over the entire globe: from the initial rumble in the Stone age, the invention of gun powder, and a steady rise during the industrial revolution, to a global acceleration in the second half of the 20th century. Hans Slabbekoorn highlights what we know about the impact of this acoustic climate change, on humans and animals alike.
Many animals rely on the acoustic environment for functions spanning mate attraction, navigation and predator and prey detection. Growing evidence focused on human-altered acoustic environments suggests that anthropogenic noise can strongly interfere with the reception of biologically relevant sounds, causing a variety of behavioural changes in response to the evolutionarily novel acoustic conditions created by humans. However, little is known about how background natural sounds, such as river noise and biotic choruses, alter behaviour. Using field-placed playback of predominantly low-frequency whitewater river rapids, higher-frequency cicada choruses (∼7.0–15.0 kHz) or a silent control, we sought to determine whether background natural sounds influence vigilance and foraging behaviour in the California ground squirrel. We found that California ground squirrels exposed to low-frequency river sounds increased vigilance and decreased foraging and movement relative to ambient acoustic conditions during control trials and, to a lesser extent, acoustic conditions imposed by the cicada chorus playback. Additionally, vigilance increased with sound level regardless of whether the playback stimulus was the low-frequency river noise or the high-frequency cicada chorus. However, background sound level interacted with group size, such that increased sound levels were associated with a strong increase in vigilance in small groups but not in larger groups. To our knowledge these results are the first to demonstrate that the spectral content and amplitude of natural sounds can influence vigilance and movement behaviours. Yet our results match those from recent studies reporting increased vigilance in response to low-frequency anthropogenic noise, suggesting that many observed responses to anthropogenic sounds may be those that animals have used to cope with variable sound levels from natural sources throughout their evolutionary history. Determining how natural sounds influence other key behaviours is ripe for future studies and will likely prove useful for predicting behavioural adjustments in response to an increasingly noisy world.
Transportation noise affects urbanized, rural, and otherwise unaltered habitats. Given expanding transportation networks, alterations in the acoustic landscapes experienced by animals are likely to be pervasive and persistent (i.e. chronic). It is important to understand if chronic noise exposure alters behavior and physiology in free-living animals, as it may result in long-lasting impacts, such as reduced reproductive success. Here, we experimentally tested the effects of chronic traffic noise on baseline and stress-induced corticosterone (the primary avian glucocorticoid), parental feeding behavior, and fitness proxies in breeding tree swallows (Tachycineta bicolor). Our results show that chronic traffic noise is related to altered corticosterone in both adult female and nestling tree swallows, suggesting that noise may be a stressor in both groups. In adult females, our results suggest that traffic noise is related to a limited ability to respond to subsequent acute stressors (i.e. reduced stress-induced corticosterone levels after handling). Further, our results show no evidence of habituation to noise during the breeding season, as the negative relationship between traffic noise and adult female stress-induced corticosterone became stronger over time. In nestlings, we found a positive relationship between traffic noise exposure and baseline corticosterone. Finally, we found a negative relationship between traffic noise and nestling body condition, despite no detectable effects of noise on nestling provisioning (e.g. parental feeding rate, or insect bolus size/composition). These results highlight the potential long-term consequences of chronic noise exposure, as increased baseline corticosterone and reduced nestling body condition in noise-exposed areas may have negative, population-level consequences.
Previous research has repeatedly shown both personality and psychological stress to predict gastrointestinal disorders and chronic diarrhea in humans. The goal of the present research was to evaluate the role of personality, as well as psychological stressors (i.e., housing relocations and rearing environment), in predicting chronic diarrhea in captive Rhesus macaques, with particular attention to how personality regulated the impact of such stressors. Subjects were 1,930 R. macaques at the California National Primate Research Center reared in a variety of environments. All subjects took part in an extensive personality evaluation at approximately 90-120 days of age. Data were analyzed using generalized linear models to determine how personality, rearing condition, housing relocations, and personality by environment interactions, predicted both diarrhea risk (an animal's risk for having diarrhea at least once) and chronic diarrhea (how many repeated bouts of diarrhea an animal had after their initial bout). Much like the human literature, we found that certain personality types (i.e., nervous, gentle, vigilant, and not confident) were more likely to have chronic diarrhea, and that certain stressful environments (i.e., repeated housing relocations) increased diarrhea risk. We further found multiple interactions between personality and environment, supporting the "interactionist" perspective on personality and health. We conclude that while certain stressful environments increase risk for chronic diarrhea, the relative impact of these stressors is highly dependent on an animal's personality.
The continuing rise in underwater sound levels in the oceans leads to disturbance of marine life. It is thought that one of the main impacts of sound exposure is the alteration of foraging behaviour of marine species, for example by deterring animals from a prey location, or by distracting them while they are trying to catch prey. So far, only limited knowledge is available on both mechanisms in the same species. The harbour porpoise (Phocoena phocoena) is a relatively small marine mammal that could quickly suffer fitness consequences from a reduction of foraging success. To investigate effects of anthropogenic sound on their foraging efficiency, we tested whether experimentally elevated sound levels would deter two captive harbour porpoises from a noisy pool into a quiet pool (Experiment 1) and reduce their prey-search performance, measured as prey-search time in the noisy pool (Experiment 2). Furthermore, we tested the influence of the temporal structure and amplitude of the sound on the avoidance response of both animals. Both individuals avoided the pool with elevated sound levels, but they did not show a change in search time for prey when trying to find a fish hidden in one of three cages. The combination of temporal structure and SPL caused variable patterns. When the sound was intermittent, increased SPL caused increased avoidance times. When the sound was continuous, avoidance was equal for all SPLs above a threshold of 100 dB re 1 μPa. Hence, we found no evidence for an effect of sound exposure on search efficiency, but sounds of different temporal patterns did cause spatial avoidance with distinct dose-response patterns.
Glucocorticoids are hormones that mediate the energetic demands that accompany environmental challenges. It is therefore not surprising that these metabolic hormones have come to dominate endocrine research on the health and fitness of wild populations. Yet, several problems have been identified in the vertebrate research that also apply to the non-human primate research. First, glucocorticoids should not be used as a proxy for fitness (unless a link has previously been established between glucocorticoids and fitness for a particular population). Second, stress research in behavioral ecology has been overly focused on "chronic stress" despite little evidence that chronic stress hampers fitness in wild animals. Third, research effort has been disproportionately focused on the causes of glucocorticoid variation rather than the fitness consequences. With these problems in mind, we have three objectives for this review. We describe the conceptual framework behind the "stress concept", emphasizing that high glucocorticoids do not necessarily indicate a stress response, and that a stress response does not necessarily indicate an animal is in poor health. Then, we conduct a comprehensive review of all studies on "stress" in wild primates, including any study that examined environmental factors, the stress response, and/or fitness (or proxies for fitness). Remarkably, not a single primate study establishes a connection between all three. Finally, we provide several recommendations for future research in the field of primate behavioral endocrinology, primarily the need to move beyond identifying the factors that cause glucocorticoid secretion to additionally focus on the relationship between glucocorticoids and fitness. We believe that this is an important next step for research on stress physiology in primates.
Although animals vary substantially in their behavioral responses to human-induced rapid environmental change (HIREC), we are only beginning to develop theory to explain this variation. Signal detection theory predicts variation in responses to novel dangerous organisms (exotic predators or toxic prey) or exotic organisms that are safe but might appear dangerous (e.g. ecotourists). Models of dispersal and habitat use explain variation in ability to cope with habitat change (loss, fragmentation). Many models assume that organisms use one main cue axis to evaluate options. New models are needed to account for the use of multiple cues. A general framework that treats genes as cues that set a ‘prior’ that can be updated by experiences predicts genetic versus plastic responses to HIREC.
Anthropogenic (man-made) noise is rapidly becoming an universal environmental feature. While the impacts of such additional noise on avian sexual signals are well documented, our understanding of its effect in other terrestrial taxa, on other vocalisations, and on receivers is more limited. Little is known, for example, about the influence of anthropogenic noise on responses to vocalisations relating to predation risk, despite the potential fitness consequences. We use playback experiments to investigate the impact of traffic noise on the responses of foraging dwarf mongooses (Helogale parvula) to surveillance calls produced by sentinels, individuals scanning for danger from a raised position whose presence usually results in reduced vigilance by foragers. Foragers exposed to surveillance calls in traffic-noise compared to ambient-noise playback exhibited a lessened response (increased personal vigilance). A second playback experiment, using noise playbacks without surveillance calls, suggests that the increased vigilance could arise in part from the direct influence of additional noise (the ‘increased threat hypothesis’) as there was an increase in response to traffic-noise playback alone. Acoustic masking could also play a role. Foragers maintained the ability to distinguish between sentinels of different dominant class, increasing personal vigilance when presented with subordinate surveillance calls compared to calls of a dominant groupmate in both noise treatments, suggesting complete masking was not occurring. However, a signal transmission experiment showed that surveillance calls were likely inaudible during periods of peak traffic, but audible during approaching traffic noise, thus reducing perceived call rate; in dwarf mongooses, lower surveillance-call rates are associated with higher risk situations, necessitating greater vigilance. While recent work has demonstrated detrimental effects of anthropogenic noise on defensive responses to actual predatory attacks, which are relatively rare, our results provide evidence of a potentially more widespread influence since animals should constantly assess background risk to optimise the foraging–vigilance trade-off.
Tools for performing model selection and model averaging. Automated model selection through subsetting the maximum model, with optional constraints for model inclusion. Model parameter and prediction averaging based on model weights derived from information criteria (AICc and alike) or custom model weighting schemes.
[Please do not request the full text - it is an R package. The up-to-date manual is available from CRAN].
The ongoing growth of the Brazilian city of Manaus-the largest urban center in the central Amazon basin-has led to extremes of habitat fragmentation and the local extinction of many animal and plant species. One species in particu- lar-the pied tamarin (Saguinus bicolor) is threatened by this process more than most, considering that its 7,500 km² geographic range coincides with the Manaus City region. This situation has led to the classification of the species in the endangered IUCN category, although it has previously been considered critically endangered. Dozens of small fragments of forest can still be found within the urban area of Manaus, and tamarins survive at many of these sites. In most cases, the urban matrix-with busy roads, power lines, and domestic animals-is virtually impenetrable, while the rural area to the east of the city is becoming increasingly fragmented. The reduced size and poor quality of most forest fragments and the eventual need for the dispersal of surplus individuals has highly deleterious implications for the survival of most populations. The ongoing deforestation of fragments for the establishment of residential areas has led to the death of many individuals and the reduction of remaining populations. In some cases, fragments are occupied by no more than one or two individuals although larger fragments, such as that of the UFAM campus, which covers 700 ha may contain dozens or even hundreds of S. bicolor. Dispersing animals risk dying in traffic, attacks from domestic animals, electric shocks from power lines, and capture as pets by local residents. For example, the access road to the UFAM campus that passes through the forest is responsible for the death of approximately 5 % of the local population per year. The generalized disrespect for environmental legislation and the lack of effort on the © Springer Science+Business Media New York 2013. All rights are reserved.
Prey species have to balance their foraging and vigilance behaviour in order to maximize nutritional and energetic intake while avoiding predation. Anthropogenic noise, a ubiquitous form of human disturbance, has the potential to influence antipredator behaviour through its effects on predator detection and perceived risk. Noise might increase perceived risk as predicted by the risk disturbance hypothesis, reduce risk by providing protection from disturbance-sensitive predators, or have no effect on antipredator behaviour if animals are tolerant of nonlethal forms of human disturbance. Road traffic is a pervasive source of anthropogenic noise, but few studies have experimentally isolated the effects of road noise on behaviour. Using systematic playback experiments, we investigated the influence of traffic noise on foraging and vigilance in a keystone species in North American prairie systems, the prairie dog, Cynomys ludovicianus. Exposure to road traffic noise significantly lowered aboveground activity, reduced foraging and increased vigilance, as predicted by the risk disturbance hypothesis. These effects were prevalent irrespective of temperature, a strong influence on such behaviours, and they were consistent across the 3-month study period, providing no evidence of habituation. Our results provide the first experimental investigation of the potential costs of this ubiquitous disturbance in a free-ranging mammal, demonstrating that road noise can alter key survival behaviours of this ecologically pivotal species. These findings highlight that the presence of animals in a location is no guarantee of population and ecological integrity, while also underlining the potential synergistic impacts of noise on a species that has already experienced severe declines across its historic range due to human disturbance. Globally, roadways have profound impacts on biodiversity, and quantifying the behavioural and fitness costs associated with different forms of disturbance such as noise is crucial for mitigation.
Several studies have demonstrated that auditory enrichment can reduce stereotypic behaviors in captive animals. The purpose of this study was to determine the relative effectiveness of three different types of auditory enrichment—naturalistic sounds, classical music, and rock music—in reducing stereotypic behavior displayed by Western lowland gorillas (Gorilla gorilla gorilla). Three gorillas (one adult male, two adult females) were observed at the Buffalo Zoo for a total of 24 hr per music trial. A control observation period, during which no sounds were presented, was also included. Each music trial consisted of a total of three weeks with a 1-week control period in between each music type. The results reveal a decrease in stereotypic behaviors from the control period to naturalistic sounds. The naturalistic sounds also affected patterns of several other behaviors including locomotion. In contrast, stereotypy increased in the presence of classical and rock music. These results suggest that auditory enrichment, which is not commonly used in zoos in a systematic way, can be easily utilized by keepers to help decrease stereotypic behavior, but the nature of the stimulus, as well as the differential responses of individual animals, need to be considered. Zoo Biol. XX:XX–XX, 2014. © 2014 Wiley Periodicals, Inc.