scholarly journals Personal information about danger trumps social information from avian alarm calls

2019 ◽  
Vol 286 (1899) ◽  
pp. 20182945 ◽  
Author(s):  
Jessica R. McLachlan ◽  
Chaminda P. Ratnayake ◽  
Robert D. Magrath

Information about predators can mean the difference between life and death, but prey face the challenge of integrating personal information about predators with social information from the alarm calls of others. This challenge might even affect the structure of interspecific information networks: species vary in response to alarm calls, potentially because different foraging ecologies constrain the acquisition of personal information. However, the hypothesis that constrained personal information explains a greater response to alarm calls has not been experimentally tested. We used a within-species test to compare the antipredator responses of New Holland honeyeaters, Phylidonyris novaehollandiae , during contrasting foraging behaviour. Compared with perched birds, which hawk for insects and have a broad view, those foraging on flowers were slower to spot gliding model predators, showing that foraging behaviour can affect predator detection. Furthermore, nectar-foraging birds were more likely to flee to alarm call playbacks. Birds also assessed social information relevance: more distant calls, and those from another species, prompted fewer flights and slower reaction times. Overall, birds made flexible decisions about danger by integrating personal and social information, while weighing information relevance. These findings support the idea that a strategic balance of personal and social information could affect community function.

2012 ◽  
Vol 58 (5) ◽  
pp. 773-780 ◽  
Author(s):  
James F. Hare ◽  
Kurtis J. Warkentin

Abstract Alarm calls are emitted by Richardson’s ground squirrels Urocitellus richardsonii in response to avian and terrestrial predators. Conspecifics detecting these calls respond with increased vigilance, promoting predator detection and evasion, but in doing so, lose time from foraging. That loss can be minimized if alarm call recipients discriminate among signalers, and weight their response accordingly. For juvenile ground squirrels, we predicted that the trade-off between foraging and vigilance could be optimized via selective response to alarm calls emitted by their own dam, and/or neighboring colony members over calls broadcast by less familiar conspecifics. Alarm calls of adult female Richardson’s ground squirrels were elicited in the field using a predator model and recorded on digital audio tape. Free-living focal juveniles were subjected to playbacks of a call of their mother, and on a separate occasion a call from either another adult female from their own colony, or an adult female from another colony. Neither immediate postural responses and escape behavior, nor the duration of vigilance manifested by juveniles differed with exposure to alarm calls of the three adult female signaler types. Thus, juveniles did not respond preferentially to alarm calls emitted by their mothers or colony members, likely reflecting the high cost of ignoring alarm signals where receivers have had limited opportunity to establish past signaler reliability.


Behaviour ◽  
1987 ◽  
Vol 102 (1-2) ◽  
pp. 15-39 ◽  
Author(s):  
Peter Marler ◽  
Roberta Pickert ◽  
Marcel Gyger

AbstractVocal alarm signals of male domestic fowl given in the presence of predators and other ground and aerial objects were recorded and analyzed. Studies were conducted under semi-naturalistic conditions and a telemetric technique was used to facilitate high quality sound recording. Cockerels gave ground alarm calls specifically to objects moving on the substrate and aerial alarm calls to objects moving above in free space. Vocalizations were associated with both dangerous and harmless objects. We therefore investigated variation in sound structure of aerial alarm calls with reference to flying predators and non-predators. A multidimensional contingency table analysis revealed a significant tendency for qualitatively different aerial alarm calls to be associated with flying predators and non-predators. Differences in call structure were restricted to the two first units of the alarm call. We tested the hypotheses that variation in aerial alarm call structure might be affected by either the distance separating the bird from the object or the angular size of the object projected onto the retina of the cockerel. Statistical analysis showed that the angular size was a good predictor of variation of the second unit of alarm call. The distance it self was less predictive. The first unit of the alarm call was not affected by either the distance or the angular size of the object. We propose that this part of the call has a more general function of alerting the conspecific companions. We conclude that alarm vocalizations of male domestic fowl refer specifically to a certain type of stimulus object, either moving on the ground or flying. For alarm calls correlated with aerial stimuli the specific angular size of a stimulus object moving in the air is a good predictor of call structure. We suggest that this way of dealing with flying objects as stimuli for alarm calls is the result of a predator detection strategy in which the benefits of an expanded field of vision, an important adaptation for ground-dwelling birds, exceed the costs of alarming to harmless birds and other aerial objects.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7572 ◽  
Author(s):  
Annabel Silvestri ◽  
Kate Morgan ◽  
Amanda R. Ridley

Alarm calls are a widespread form of antipredator defence and being alerted to the presence of predators by the alarm calls of conspecifics is considered one of the benefits of group living. However, while social information can allow an individual to gain additional information, it can also at times be inaccurate or irrelevant. Such variation in the accuracy of social information is predicted to select for receivers to discriminate between sources of social information. In this study, we used playback experiments to determine whether Western Australian magpies (Cracticus tibicen dorsalis) respond to the predator information associated with alarm calls. Magpies were exposed to the alarm calls of two group members that differed in the threat associated with the alarm call: one call was played in the presence of a predator model while the other was not—in order to establish differences in the predator information provided by each caller. We then played back the alarm calls of the same group members in the absence of the predator model to determine whether magpies responded differently to signallers in response to the previous association between the alarm call and a predator threat. We found that receivers showed significantly greater levels of responsiveness to signallers that previously gave alarm calls in the appropriate context. Thus, the accuracy of threat-based information influenced subsequent receiver response.


Author(s):  
Li Hsieh

Bilingual speakers rely on attentional and executive control to continuously inhibit or activate linguistic representations of competing languages, which leads to an increased efficiency known as “bilingual advantage”. Both monolingual and bilingual speakers were asked to perform multiple tasks of talking on a cell phone while simultaneously attending to simulated driving events. This study examined the effect of bilingualism on participants' performance during a dual-task experiment based on 20 monolingual and 13 bilingual healthy adults. The within-subject and between-subject comparisons were conducted on reaction times of a visual event detection task for (a) only driving and (b) driving while simultaneously engaged in a phone conversation. Results of this study showed that bilingual speakers performed significantly faster than monolingual speakers during the multitasking condition, but not during the driving only condition. Further, bilingual speakers consistently showed a bilingual advantage in reaction times during the multitasking condition, despite varying degrees on a bilingual dominance scale. Overall, experiences in more than one language yield bilingual advantage in better performance than monolingual speakers during a multitasking condition, but not during a single task condition. Regardless of the difference in bilingual proficiency level, such language experience reveals a positive impact on bilingual speakers for multitasking.


2018 ◽  
Vol 15 (148) ◽  
pp. 20180578 ◽  
Author(s):  
Hannah J. Williams ◽  
Andrew J. King ◽  
Olivier Duriez ◽  
Luca Börger ◽  
Emily L. C. Shepard

Vultures are thought to form networks in the sky, with individuals monitoring the movements of others to gain up-to-date information on resource availability. While it is recognized that social information facilitates the search for carrion, how this facilitates the search for updrafts, another critical resource, remains unknown. In theory, birds could use information on updraft availability to modulate their flight speed, increasing their airspeed when informed on updraft location. In addition, the stylized circling behaviour associated with thermal soaring is likely to provide social cues on updraft availability for any bird operating in the surrounding area. We equipped five Gyps vultures with GPS and airspeed loggers to quantify the movements of birds flying in the same airspace. Birds that were socially informed on updraft availability immediately adopted higher airspeeds on entering the inter-thermal glide; a strategy that would be risky if birds were relying on personal information alone. This was embedded within a broader pattern of a reduction in airspeed (approx. 3 m s −1 ) through the glide, likely reflecting the need for low speed to sense and turn into the next thermal. Overall, this demonstrates (i) the complexity of factors affecting speed selection over fine temporal scales and (ii) that Gyps vultures respond to social information on the occurrence of energy in the aerial environment, which may reduce uncertainty in their movement decisions.


2017 ◽  
Vol 284 (1861) ◽  
pp. 20171083 ◽  
Author(s):  
David J. White ◽  
Hayden B. Davies ◽  
Samuel Agyapong ◽  
Nora Seegmiller

Brood parasites face considerable cognitive challenges in locating and selecting host nests for their young. Here, we test whether female brown-headed cowbirds, Molothrus ater , could use information acquired from observing the nest prospecting patterns of conspecifics to influence their own patterns of nest selection. In laboratory-based experiments, we created a disparity in the amount of personal information females had about the quality of nests. Females with less personal information about the quality of two nests spent more time investigating the nest that more knowledgeable females investigated. Furthermore, there was a strong negative relationship between individual's ability to track nest quality using personal information and their tendency to copy others. These two contrasting strategies for selecting nests are equally effective, but lead to different patterns of parasitism.


2016 ◽  
Vol 81 (6) ◽  
pp. 697-705 ◽  
Author(s):  
Xuepeng Yang ◽  
Yan Ji ◽  
Fangfang Wang ◽  
Jia Xu ◽  
Xiangzhen Liu ◽  
...  

Vibrio fischeri bioluminescence inhibition has been widely used to test acute toxicities of metals and organics contaminants. However, the differences of metals and organics acute toxicities to V. fischeri have not been compared. Here, four heavy metals (Zn2+, Cu2+, Cd2+, Cr6+) and five organics (phenol, benzoic acid, p-hydroxy benzoic acid, nitro-benzene and benzene) acute toxicities to V. fischeri were investigated. Heavy metals toxicities to V. fischeri were increased along with the reaction time, while the organics toxicities kept the same level in different reaction times. In order to explain the difference, the relative cell death rate of V. fischeri was detected. In metals toxicities tests, the bioluminescence inhibition rate of V. fischeri was found to be significantly higher than the relative cell death rate (P<0.05), while for the organics toxicities tests, the cell death rate was similar to the bioluminescence inhibition rate. These results indicated that organics acute toxicities to V. fischeri could reflect the death of cell, but metals acute toxicities to V. fischeri may not lead to the death of cell, just represent the bioluminescence inhibition.


2019 ◽  
Vol 9 (7) ◽  
pp. 496-513 ◽  
Author(s):  
Fadime Çinar*, Turgay Sirin

Background: One of the indispensable aspects of the philosophy of holistic care,and negative situations such as life-threatening illness, spiritual well-being, which isdefined as the search for a relationship with a divine soul, is a requirement that mustbe met in order to maintain the existence of the individual. The patient's need forsocial and spiritual well-being increases even more in cases of long-term treatment,such as cancer, that reduce the quality of life. Determining and meeting the spiritualneeds of the individual in the difficult times of the crisis can be realized bydetermining the spiritual well-being levels of the individuals and by providing theindividual spiritual care. This study was conducted to determine the level of thespiritual well-being of palliative care patients diagnosed with cancer. Methods: Thisis a descriptive study. The population of the study consisted of 124 patientsdiagnosed with cancer who were hospitalized in the palliative unit between Januaryand August 2018 and were treated in two state hospitals operating on the Europeanside of Istanbul. The sample consisted of 111 people with voluntary participationand communication. Personal Information Form and Spiritual Well-being Scalewere used to collect data. Data were evaluated by one-way analysis of variance (one-way anova) and significance (t-test) of the difference between the two means.Results: The total score averages from the spiritual good scale of individualsparticipating in the Study were determined to be good with x = 4,15. In terms ofthe level of education of Scale scores, only "Anomi" is significantly differentiatedbetween groups of age, with a total score of the scale, In the sub-dimension oftranscendity and the subdimension of "Harmony with Nature" according to thevariable metastasis (p > 0.05). Conclusion: Spiritual Well-being has a positive effecton the healing process of individuals with impaired health. It helps individuals whohave a crisis in life threatening diseases such as Cancer to cope with this crisis and toprovide spiritual well-being in the sense of life. In This process, spiritual careinitiatives by healthcare professionals can be transformed into a part of the healingprocess and the spiritual goodness of the individual can be increased. Furtherresearch in This area is projected to contribute to the richening of the relevantliterature in Turkey.Key words: Spiritual, spiritual well-being, palliative care, palliative care unit


2021 ◽  
Vol 12 ◽  
Author(s):  
James M. Bjork ◽  
Lori Keyser-Marcus ◽  
Jasmin Vassileva ◽  
Tatiana Ramey ◽  
David C. Houghton ◽  
...  

Positive social connections are crucial for recovery from Substance Use Disorder (SUD). Of interest is understanding potential social information processing (SIP) mediators of this effect. To explore whether persons with different SUD show idiosyncratic biases toward social signals, we administered an emotional go-nogo task (EGNG) to 31 individuals with Cocaine Use Disorder (CoUD), 31 with Cannabis Use Disorder (CaUD), 79 with Opioid Use Disorder (OUD), and 58 controls. Participants were instructed to respond to emotional faces (Fear/Happy) but withhold responses to expressionless faces in two task blocks, with the reverse instruction in the other two blocks. Emotional faces as non-targets elicited more “false alarm” (FA) commission errors as a main effect. Groups did not differ in overall rates of hits (correct responses to target faces), but participants with CaUD and CoUD showed reduced rates of hits (relative to controls) when expressionless faces were targets. OUD participants had worse hit rates [and slower reaction times (RT)] when fearful faces (but not happy faces) were targets. CaUD participants were most affected by instruction effects (respond/“go” vs withhold response/“no-go” to emotional face) on discriminability statistic A. Participants were faster to respond to happy face targets than to expressionless faces. However, this pattern was reversed in fearful face blocks in OUD and CoUD participants. This experiment replicated previous findings of the greater salience of expressive face images, and extends this finding to SUD, where persons with CaUD may show even greater bias toward emotional faces. Conversely, OUD participants showed idiosyncratic behavior in response to fearful faces suggestive of increased attentional disruption by fear. These data suggest a mechanism by which positive social signals may contribute to recovery.


2021 ◽  
Vol 11 ◽  
Author(s):  
Wang Xiang

To investigate whether implicit detection occurs uniformly during change blindness with single or combination feature stimuli, and whether implicit detection is affected by exposure duration and delay, two one-shot change detection experiments are designed. The implicit detection effect is measured by comparing the reaction times (RTs) of baseline trials, in which stimulus exhibits no change and participants report “same,” and change blindness trials, in which the stimulus exhibits a change but participants report “same.” If the RTs of blindness trials are longer than those of baseline trials, implicit detection has occurred. The strength of the implicit detection effect was measured by the difference in RTs between the baseline and change blindness trials, where the larger the difference, the stronger the implicit detection effect. In both Experiments 1 and 2, the results showed that the RTs of change blindness trials were significantly longer than those of baseline trials. Whether under set size 4, 6, or 8, the RTs of the change blindness trials were significantly longer than those in the baseline trials. In Experiment 1, the difference between the baseline trials’ RTs and change blindness trials’ RTs of the single features was significantly larger than that of the combination features. However, in Experiment 2, the difference between the baseline trials’ RTs and the change blindness trials’ RTs of single features was significantly smaller than that of the combination features. In Experiment 1a, when the exposure duration was shorter, the difference between the baseline and change blindness trials’ RTs was smaller. In Experiment 2, when the delay was longer, the difference between the two trials’ RTs was larger. These results suggest that regardless of whether the change occurs in a single or a combination of features and whether there is a long exposure duration or delay, implicit detection occurs uniformly during the change blindness period. Moreover, longer exposure durations and delays strengthen the implicit detection effect. Set sizes had no significant impact on implicit detection.


Sign in / Sign up

Export Citation Format

Share Document