scholarly journals Competition and group size in Thomas's langurs ( Presbytis thomasi ): the folivore paradox revisited

2001 ◽  
Vol 49 (2-3) ◽  
pp. 100-110 ◽  
Author(s):  
R. Steenbeek ◽  
Carel P. van Schaik
Keyword(s):  
Group Size ◽  
Folivore Paradox ◽  
Presbytis Thomasi

scholarly journals Male monkeys remember which group members have given alarm calls

2005 ◽  
Vol 273 (1587) ◽  
pp. 735-740 ◽  
Author(s):  
Serge A Wich ◽  
Han de Vries
Keyword(s):  
Group Size ◽  
Alarm Call ◽  
Alarm Calls ◽  
Unanswered Question ◽  
Alarm Calling ◽  
Group Members ◽  
Presbytis Thomasi ◽  
Group Member

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.

An ecological basis for large group size in Colobus angolensis in the Nyungwe Forest, Rwanda

2001 ◽  
Vol 39 (1) ◽  
pp. 83-92 ◽  
Author(s):  
Cheryl Fimbel ◽  
Amy Vedder ◽  
Ellen Dierenfeld ◽  
Felix Mulindahabi
Keyword(s):  
Group Size ◽  
Large Group ◽  
Colobus Angolensis ◽  
Ecological Basis

Bystanders, Group Size and the Informal Regulation of Violence

2008 ◽  
Author(s):  
Mark Levine ◽  
Rachel Best ◽  
Paul Taylor
Keyword(s):  
Group Size ◽  
Informal Regulation

Conformity and group size.

1968 ◽  
Vol 8 (1, Pt.1) ◽  
pp. 79-82 ◽  
Author(s):  
Harold B. Gerard ◽  
Roland A. Wilhelmy ◽  
Edward S. Conolley
Keyword(s):  
Group Size

Effects of group-size-floor space allowance during the nursery phase of production on growth, physiology, and hematology in replacement gilts

2017 ◽  
Vol 95 (1) ◽  
pp. 201
Author(s):  
S. R. Callahan ◽  
A. J. Cross ◽  
A. E. DeDecker ◽  
M. D. Lindemann ◽  
M. J. Estienne
Keyword(s):  
Group Size ◽  
Growth Physiology ◽  
Floor Space

Subjective Fear Dilutes as Group Size Increases

2020 ◽  
Author(s):  
dean mobbs ◽  
Ellen Tedeschi ◽  
Anastasia Buyalskaya ◽  
Brian Silston
Keyword(s):  
Group Size ◽  
Real World ◽  
Survival Benefit ◽  
Group Living ◽  
External Factors ◽  
Threat Perception ◽  
Perception Of Threat ◽  
Threat Level ◽  
Internal States ◽  
Risk Dilution

According to Hamilton’s Selfish Herd Theory, a crucial survival benefit of group living is that it provides a ‘risk dilution’ function against predation. Despite a large literature on group living benefits in animals, few studies have been conducted on how group size alters subjective fear or threat perception in humans, and on what factors drive preferences for being in groups when facing threats. We conducted seven experiments (N=3,838) to test (A) if the presence of others decreases perception of threat under a variety of conditions. In studies 1 to 3, we experimentally manipulated group size in hypothetical and real-world situations, to show that fear responses decreased as group size increased. In studies 4 to 7 we again used a combination of hypothetical, virtual and real-world decisions to test (B) how internal states (e.g. anxiety) and external factors (e.g. threat level, availability of help) affected participants’ preference for groups. Participants consistently chose larger groups when threat and anxiety were high. Overall, our findings show that group size provides a salient signal of protection and safety.

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