scholarly journals Female putty-nosed monkeys ( Cercopithecus nictitans ) vocally recruit males for predator defence

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Frederic Gnepa Mehon ◽  
Claudia Stephan

Alarm calls can trigger very different behavioural changes in receivers and signallers might apply different alarm call strategies based on their individual cost-benefit ratio. These cost-benefit ratios can also vary as a function of sex. For instance, male but not female forest guenons possess loud alarms that serve warning and predator deterrence functions, but also intergroup spacing and male–male competition. In some forest guenons, the context specificity and alarm call repertoire size additionally differs between females and males but it remains unclear if this corresponds to similar sexual dimorphisms in alarm calling strategies. We here experimentally investigated whether general female and more context-specific male alarm calls in putty-nosed monkeys ( Cercopithecus nictitans ) had different effects on the opposite sex's behaviour and whether they might serve different female and male alarm calling strategies. We presented a leopard model separately to the females or to the male of several groups while ensuring that the opposite sex only heard alarm calls of target individuals. While female alarms led to the recruitment of males in the majority of cases, male alarms did not have a similar effect on female behaviour. Males further seem to vocally advertise their engagement in group defence with more unspecific alarms while approaching their group. Males switched alarm call types once they spotted the leopard model and started mobbing behaviour. Females only ceased to alarm call when males produced calls typically associated with anti-predator defence, but not when males produced unspecific alarm calls. Our results suggest that sexual dimorphisms in the context specificity of alarms most likely correspond to different alarm calling strategies in female and male putty-nosed monkeys.

2008 ◽  
Vol 4 (6) ◽  
pp. 641-644 ◽  
Author(s):  
Claudia Stephan ◽  
Klaus Zuberbühler

According to most accounts, alarm calling in non-human primates is a biologically hardwired behaviour with signallers having little control over the acoustic structure of their calls. In this study, we compared the alarm calling behaviour of two adjacent populations of Diana monkeys at Taï forest (Ivory Coast) and Tiwai Island (Sierra Leone), which differ significantly in predation pressure. At Taï, monkeys regularly interact with two major predators, crowned eagles and leopards, while at Tiwai, monkeys are only hunted by crowned eagles. We monitored the alarm call responses of adult male Diana monkeys to acoustic predator models. We found no site-specific differences in the types of calls given to eagles, leopards and general disturbances, but there were consistent differences in how callers assembled calls into sequences. At Tiwai, males responded to leopards and general disturbances in the same way, while at Taï, males discriminated by giving call sequences that differed in the number of component calls. Responses to eagles were identical at both sites. We concluded that Diana monkeys are predisposed to use their repertoire in context-specific ways, but that ontogenetic experience determines how individual calls are assembled into meaningful sequences.


Behaviour ◽  
2021 ◽  
pp. 1-20
Author(s):  
Estelle Meaux ◽  
Chao He ◽  
Luying Qin ◽  
Eben Goodale

Abstract Vocalizations that signal predation risk such as alarm calls provide crucial information for the survival of group-living individuals. However, alarm calling may attract the predator’s attention and, to avoid this cost, animals can opt for alternative strategies to indicate danger, such as ‘adaptive silence’, which is the cessation of vocalizations. We investigate here whether abrupt contact call cessation would provoke alarm responses, or would reinforce the signal given by an alarm call. In an aviary setting, we conducted playback experiments with a group-living passerine, the Swinhoe’s white-eye, Zosterops simplex. We found that birds did not respond to a sudden call cessation, nor did they have a stronger response to alarm calls followed by silence than to alarm calls followed by contact calls. Confirming previous work investigating contact call rate, it appears that in this species contact calls encode information about social factors but not environmental conditions.


Behaviour ◽  
1999 ◽  
Vol 136 (6) ◽  
pp. 731-757 ◽  
Author(s):  
Daniel Blumstein

AbstractMany species produce alarm calls that vary according to situation. Theoretically, alarm call structure could covary with predator type and could communicate potentially ''referential information, or calls could covary with the degree of risk a caller experienced when it emitted a call. Using similar methods, I studied the ways in which Olympic (Marmota olympus), hoary (M. caligata), and Vancouver Island marmots (M. vancouverensis) communicated situational variation. I observed both natural alarm calling, and I artificially elicited alarm calls with simulated terrestrial and aerial predators. I used playback experiments to study marmots' responses to different alarm call variants. All three species produced four roughly similar but distinctive loud alarm vocalizations that could be categorized by their relative shape, duration, and whether calls were quickly repeated to create multi-note vocalizations. In addition, the Vancouver Island marmot produced a fifth loud alarm call-the kee-aw. Call micro-structure varied as a function of the distance the caller was from an alarming stimulus and the type of alarming stimulus. Two lines of evidence suggest that all three species had alarm calls associated with the caller's risk (i.e. they were not referential). First, marmots often changed call types within a calling bout: there were no unique stimulus-class specific vocalizations. Second, marmot responses to alarm calls were graded: marmots did not have unique responses to different call types. These three close taxonomic relatives with superficially similar calls, communicated risk differently.


The Auk ◽  
2005 ◽  
Vol 122 (1) ◽  
pp. 108-120 ◽  
Author(s):  
Eben Goodale ◽  
Sarath W. Kotagama

Abstract Vocal alarm calls are important to the vigilance and likely the organization of mixed-species flocks, but community-wide studies of alarm calling in flocks are lacking. We investigated which species alarm-call, and the characteristics of their calls, in a large flock system of a Sri Lankan rainforest. We recorded naturally elicited alarm calls during several attacks by Accipiter hawks and while following flocks for 10 h. We then artificially elicited alarms by throwing a stick to the side of the flock, in a total of 70 trials at 30 flock sites. The Orange-billed Babbler (Turdoides rufescens) was the most frequent caller to both the artificial and natural stimuli, followed by the Greater Racket-tailed Drongo (Dicrurus paradiseus). Several other species also called, and multiple species often called to the same stimulus (in 23 trials, and in all of the hawk attacks). The species differed in their rapidity of response and in their sensitivity to different natural stimuli. Calls of the gregarious babbler usually provided a first, unreliable warning of an incoming threat, whereas later calls of other species emphasized the seriousness of the threat. We suggest that birds in mixed-species flocks may be particularly aware of aerial predators for two reasons: (1) a “numbers effect,” whereby nongregarious species are more aware of predators when surrounded by large numbers of other species; and (2) an “information effect,” whereby species differ in the information available in their alarm calls, leading to an accumulation of information in a mixed-species flock. Llamadas de Alarma en Bandadas Mixtas de Aves en Sri Lanka


2013 ◽  
Vol 9 (6) ◽  
pp. 20130745 ◽  
Author(s):  
Tonya M. Haff ◽  
Robert D. Magrath

Communication about predators can reveal the effects of both conspecific and heterospecific audiences on signalling strategy, providing insight into signal function and animal cognition. In species that alarm call to their young, parents face a fundamental dilemma: calling can silence noisy offspring and so make them less likely to be overheard, but can also alert predators that young are nearby. Parents could resolve this dilemma by being sensitive to the current vulnerability of offspring, and calling only when young are most at risk. Testing whether offspring vulnerability affects parental strategy has proved difficult, however, because more vulnerable broods are often also more valuable. We tested experimentally whether parent white-browed scrubwren, Sericornis frontalis , assessed brood noisiness when alarm calling near nests . When a model predator was nearby, parents gave more alarm calls when playbacks simulated noisy broods, yet brood noisiness did not affect adult calling when only a control model was present. Parents were therefore sensitive to the tradeoff between silencing young and alerting predators to the presence of nests. Our study demonstrates that receiver vulnerability can affect signalling decisions in species other than primates.


1994 ◽  
Vol 72 (6) ◽  
pp. 1087-1092 ◽  
Author(s):  
Karen Burke da Silva ◽  
Donald L. Kramer ◽  
Daniel M. Weary

The structure and context of alarm calls produced by chipmunks (Tamias striatus) at a field site in southern Quebec were recorded during opportunistic field observations and experimentally simulated hawk attacks. Chipmunks produced three call types in the presence of predators. Chipping consisted of a series of high frequency notes with a rapid downward frequency slope (9.6 to 2.8 kHz) and was given in the presence of mammalian predators by chipmunks perched on a raised vantage point. Chucking consisted of a series of lower frequency notes also sloping downwards (2.5 to 0.4 kHz), given in the presence of avian predators by perched animals. The trill was a lower amplitude, multi-note call usually given only once by animals before reaching a refuge while fleeing from either type of predator. The average trill contained 6–11 downward sloping notes (7.3 to 0.8 kHz). The alarm call types of eastern chipmunks appear to be similar to those reported for western chipmunks. However, they differ in the clear separation of the calls for aerial and terrestrial predators. Chipmunks differ from most other terrestrial sciurids in giving repeated calls for aerial as well as terrestrial predators and in using a call just before reaching a secure refuge.


2005 ◽  
Vol 273 (1587) ◽  
pp. 735-740 ◽  
Author(s):  
Serge A Wich ◽  
Han de Vries

Primates give alarm calls in response to the presence of predators. In some species, such as the Thomas langur ( Presbytis thomasi ), males only emit alarm calls if there is an audience. An unanswered question is whether the audience's behaviour influences how long the male will continue his alarm calling. We tested three hypotheses that might explain the alarm calling duration of male Thomas langurs: the fatigue , group size and group member behaviour hypotheses. Fatigue and group size did not influence male alarm calling duration. We found that males only ceased calling shortly after all individuals in his group had given at least one alarm call. This shows that males keep track of and thus remember which group members have called.


2021 ◽  
Vol 75 (8) ◽  
Author(s):  
Auriane Le Floch ◽  
Alice Bouchard ◽  
Quentin Gallot ◽  
Klaus Zuberbühler

Abstract Forest monkeys often form semi-permanent mixed-species associations to increase group-size related anti-predator benefits without corresponding increases in resource competition. In this study, we analysed the alarm call system of lesser spot-nosed monkeys, a primate that spends most of its time in mixed-species groups while occupying the lowest and presumably most dangerous part of the forest canopy. In contrast to other primate species, we found no evidence for predator-specific alarm calls. Instead, males gave one general alarm call type (‘kroo’) to three main dangers (i.e., crowned eagles, leopards and falling trees) and a second call type (‘tcha-kow’) as a coordinated response to calls produced in non-predatory contexts (‘boom’) by associated male Campbell’s monkeys. Production of ‘kroo’ calls was also strongly affected by the alarm calling behaviour of male Campbell’s monkeys, suggesting that male lesser spot-nosed monkeys adjust their alarm call production to another species’ vocal behaviour. We discuss different hypotheses for this unusual phenomenon and propose that high predation pressure can lead to reliance on other species vocal behaviour to minimise predation. Significance statement Predation can lead to the evolution of acoustically distinct, predator-specific alarm calls. However, there are occasional reports of species lacking such abilities, despite diverse predation pressure, suggesting that evolutionary mechanisms are more complex. We conducted field experiments to systematically describe the alarm calling behaviour of lesser spot-nosed monkeys, an arboreal primate living in the lower forest strata where pressure from different predators is high. We found evidence for two acoustically distinct calls but, contrary to other primates in the same habitat, no evidence for predator-specific alarms. Instead, callers produced one alarm call type (‘kroo’) to all predator classes and another call type (‘tcha-kow’) to non-predatory dangers, but only as a response to a specific vocalisation of Campbell’s monkeys (‘boom’). The production of both calls was affected by the calling behaviour of Campbell’s monkeys, suggesting that lesser spot-nosed monkey vocal behaviour is dependent on the antipredator behaviour of other species. Our study advances the theory of interspecies interactions and evolution of alarm calls.


2002 ◽  
Vol 41 (01) ◽  
pp. 3-13 ◽  
Author(s):  
M. Schäfers

SummaryNuclear cardiological procedures have paved the way for non-invasive diagnostics of various partial functions of the heart. Many of these functions cannot be visualised for diagnosis by any other method (e. g. innervation). These techniques supplement morphological diagnosis with regard to treatment planning and monitoring. Furthermore, they possess considerable prognostic relevance, an increasingly important issue in clinical medicine today, not least in view of the cost-benefit ratio.Our current understanding shows that effective, targeted nuclear cardiology diagnosis – in particular for high-risk patients – can contribute toward cost savings while improving the quality of diagnostic and therapeutic measures.In the future, nuclear cardiology will have to withstand mounting competition from other imaging techniques (magnetic resonance imaging, electron beam tomography, multislice computed tomography). The continuing development of these methods increasingly enables measurement of functional aspects of the heart. Nuclear radiology methods will probably develop in the direction of molecular imaging.


2020 ◽  
Vol 19 (1) ◽  
pp. 13
Author(s):  
Leury Max Da Silva Chaves ◽  
Gabriel Vinicius Santos ◽  
Cauê La Scala Teixeira ◽  
Marzo Edir Da Silva-Grigoletto

 Bodyweight exercises (also popularly known as calisthenics) is a classic training method and its practice has been widespread since the 19th century, but little evidenced in the scientific literature over the years. This type of training aims to promote multi-system adaptations using body weight as an overload with no or few implements [1–3]. This characteristic makes exercise with body weight easy to apply, in addition to having an excellent cost-benefit ratio when compared to other training possibilities that require machines or materials [4,5].


Sign in / Sign up

Export Citation Format

Share Document