Song Sharing in a Group-Living Songbird, the Australian Magpie. Part Ii. Vocal Sharing Between Territorial Neighbors, Within and Between Geographic Regions, and Between Sexes

Behaviour ◽  
1988 ◽  
Vol 104 (1-2) ◽  
pp. 105-125 ◽  
Author(s):  
Eleanor D. Brown ◽  
Susan M. Farabaugh ◽  
Clare J. Veltman
Keyword(s):  
Group Living ◽  
Song Sharing ◽  
Geographic Regions ◽  
Australian Magpie

scholarly journals Deceptive vocal duets and multimodal display in a songbird

2017 ◽  
Vol 284 (1864) ◽  
pp. 20171774 ◽  
Author(s):  
Paweł Ręk ◽  
Robert D. Magrath
Keyword(s):  
Group Living ◽  
Visual Display ◽  
Reliable Information ◽  
Song Type ◽  
Visual Displays ◽  
Visual Component ◽  
Song Types ◽  
Multimodal Signalling ◽  
Australian Magpie ◽  
Vocal Duets

Many group-living animals cooperatively signal to defend resources, but what stops deceptive signalling to competitors about coalition strength? Cooperative-signalling species include mated pairs of birds that sing duets to defend their territory. Individuals of these species sometimes sing ‘pseudo-duets’ by mimicking their partner's contribution, but it is unknown if these songs are deceptive, or why duets are normally reliable. We studied pseudo-duets in Australian magpie-larks, Grallina cyanoleuca , and tested whether multimodal signalling constrains deception. Magpie-larks give antiphonal duets coordinated with a visual display, with each sex typically choosing a different song type within the duet. Individuals produced pseudo-duets almost exclusively during nesting when partners were apart, but the two song types were used in sequence rather than antiphonally. Strikingly, birds hid and gave no visual displays, implying deceptive suppression of information. Acoustic playbacks showed that pseudo-duets provoked the same response from residents as true duets, regardless of whether they were sequential or antiphonal, and stronger response than that to true duets consisting of a single song type. By contrast, experiments with robot models showed that songs accompanied by movements of two birds prompted stronger responses than songs accompanied by movements of one bird, irrespective of the number of song types or singers. We conclude that magpie-larks used deceptive pseudo-duets when partners were apart, and suppressed the visual display to maintain the subterfuge. We suggest that the visual component of many species' duets provides the most reliable information about the number of signallers and may have evolved to maintain honesty in duet communication.

Language and Literacy Predictors of Dialect Density Among School-Age African American Children From Two Geographic Regions

2020 ◽  
Vol 51 (3) ◽  
pp. 807-820
Author(s):  
Lena G. Caesar ◽  
Marie Kerins
Keyword(s):  
African American ◽  
Multiple Regression ◽  
Oral Language ◽  
East Coast ◽  
Geographic Region ◽  
Literacy Skills ◽  
School Age ◽  
Regression Analyses ◽  
Geographic Regions ◽  
American Children

Purpose The purpose of this study was to investigate the relationship between oral language, literacy skills, age, and dialect density (DD) of African American children residing in two different geographical regions of the United States (East Coast and Midwest). Method Data were obtained from 64 African American school-age children between the ages of 7 and 12 years from two geographic regions. Children were assessed using a combination of standardized tests and narrative samples elicited from wordless picture books. Bivariate correlation and multiple regression analyses were used to determine relationships to and relative contributions of oral language, literacy, age, and geographic region to DD. Results Results of correlation analyses demonstrated a negative relationship between DD measures and children's literacy skills. Age-related findings between geographic regions indicated that the younger sample from the Midwest outscored the East Coast sample in reading comprehension and sentence complexity. Multiple regression analyses identified five variables (i.e., geographic region, age, mean length of utterance in morphemes, reading fluency, and phonological awareness) that accounted for 31% of the variance of children's DD—with geographic region emerging as the strongest predictor. Conclusions As in previous studies, the current study found an inverse relationship between DD and several literacy measures. Importantly, geographic region emerged as a strong predictor of DD. This finding highlights the need for a further study that goes beyond the mere description of relationships to comparing geographic regions and specifically focusing on racial composition, poverty, and school success measures through direct data collection.

The incumbent, challenger, and population during revolution and civil war

2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Kjell Hausken ◽  
Mthuli Ncube
Keyword(s):  
Civil War ◽  
Public Goods ◽  
Arab Spring ◽  
The Other ◽  
Time Period ◽  
Geographic Regions

We consider revolutions and civil war involving an incumbent, a challenger, and the population. Revolutions are classified into eight outcomes. In four outcomes incumbent repression occurs (viewed as providing sub-threshold benefits such as public goods to the population). Accommodation occurs in the other four outcomes (benefits provision above a threshold). The incumbent and challenger fight each other. The incumbent may win and retain power or else lose, thereby causing standoff or coalition. In a standoff, which is costly, no one backs down and uncertainty exists about who is in power. In a coalition, which is less costly, the incumbent and challenger cooperate, compromise, and negotiate their differences. If the population successfully revolts against the incumbent, the challenger replaces the incumbent. Eighty-seven revolutions during 1961–2011, including the recent Arab spring revolutions, are classified into the eight outcomes. When repressive, the incumbent loses 46 revolutions, remains in power through 21 revolutions, and builds a coalition after 12 revolutions. When accommodative, the incumbent loses seven revolutions and builds a coalition after one revolution. The 87 revolutions are classified across geographic regions and by time-period.

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.

Characterization of Growth Period Structure and Identification of E Genes of MGⅢ Soybean Varieties from Different Geographic Regions

2018 ◽  
Vol 44 (10) ◽  
pp. 1448
Author(s):  
Hong JIANG ◽  
Shi SUN ◽  
Wen-Wen SONG ◽  
Cun-Xiang WU ◽  
Ting-Ting WU ◽  
...  
Keyword(s):  
Growth Period ◽  
Geographic Regions
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