scholarly journals Group decisions and individual differences: route fidelity predicts flight leadership in homing pigeons ( Columba livia )

2010 ◽  
Vol 7 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Robin Freeman ◽  
Richard Mann ◽  
Tim Guilford ◽  
Dora Biro
Keyword(s):  
Individual Differences ◽  
Individual Variation ◽  
Columba Livia ◽  
Homing Pigeon ◽  
Scientific Interest ◽  
Homing Pigeons ◽  
Collective Decisions ◽  
The Subject ◽  
Leadership Decisions

How social-living animals make collective decisions is currently the subject of intense scientific interest, with increasing focus on the role of individual variation within the group. Previously, we demonstrated that during paired flight in homing pigeons, a fully transitive leadership hierarchy emerges as birds are forced to choose between their own and their partner's habitual routes. This stable hierarchy suggests a role for individual differences mediating leadership decisions within homing pigeon pairs. What these differences are, however, has remained elusive. Using novel quantitative techniques to analyse habitual route structure, we show here that leadership can be predicted from prior route-following fidelity. Birds that are more faithful to their own route when homing alone are more likely to emerge as leaders when homing socially. We discuss how this fidelity may relate to the leadership phenomenon, and propose that leadership may emerge from the interplay between individual route confidence and the dynamics of paired flight.

scholarly journals Lack of experience-based stratification in homing pigeon leadership hierarchies

2016 ◽  
Vol 3 (1) ◽  
pp. 150518 ◽  
Author(s):  
Isobel Watts ◽  
Benjamin Pettit ◽  
Máté Nagy ◽  
Theresa Burt de Perera ◽  
Dora Biro
Keyword(s):  
Prior Experience ◽  
Release Site ◽  
Homing Pigeon ◽  
Fundamental Question ◽  
Leadership Roles ◽  
Homing Pigeons ◽  
Adaptive Value ◽  
Collective Decisions ◽  
Group Members ◽  
The Individual

In societies that make collective decisions through leadership, a fundamental question concerns the individual attributes that allow certain group members to assume leadership roles over others. Homing pigeons form transitive leadership hierarchies during flock flights, where flock members are ranked according to the average time differences with which they lead or follow others' movement. Here, we test systematically whether leadership ranks in navigational hierarchies are correlated with prior experience of a homing task. We constructed experimental flocks of pigeons with mixed navigational experience: half of the birds within each flock had been familiarized with a specific release site through multiple previous releases, while the other half had never been released from the same site. We measured the birds' hierarchical leadership ranks, then switched the same birds' roles at a second site to test whether the relative hierarchical positions of the birds in the two subsets would reverse in response to the reversal in levels of experience. We found that while across all releases the top hierarchical positions were occupied by experienced birds significantly more often than by inexperienced ones, the remaining experienced birds were not consistently clustered in the top half—in other words, the network did not become stratified. We discuss our results in light of the adaptive value of structuring leadership hierarchies according to ‘merit’ (here, navigational experience).

Acquisition of a Same-Different Discrimination Task by Pigeons (Columba Livia)

2012 ◽  
Vol 110 (1) ◽  
pp. 251-262
Author(s):  
Hiromitsu Miyata ◽  
Kazuo Fujita
Keyword(s):  
Individual Variation ◽  
Discrimination Task ◽  
Columba Livia ◽  
The Other ◽  
Chance Level ◽  
Learning Criterion ◽  
Homing Pigeons ◽  
Considerable Individual Variation

Four homing pigeons were trained to discriminate two figures simultaneously presented on an LCD screen. The figure was either a rectangle (A) or a square (B), and four combinations of the two figures, AA, AB, BA, BB, appeared in a pseudo-randomized order. The pigeons' task was to peck one of these figures based upon whether the two figures were identical or not. One pigeon successfully learned this discrimination, with proportions of correct responses above 90% in two consecutive sessions. Of the other birds, two performed above chance level but had difficulty meeting a learning criterion of above 80% in two consecutive sessions. All birds achieved this criterion when the combinations of figures presented were reduced to two. Results suggested that learning the present same-different discrimination is within the capacity of pigeons to a certain extent, although there exists considerable individual variation in the pigeons' skills to acquire complex discrimination.

scholarly journals Whole genome resequencing data for rock pigeon (Columba livia)

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ali Esmailizadeh ◽  
Hamed Kharrati-Koopaee ◽  
Hojjat Assadoullahpour Nanaei
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Columba Livia ◽  
Homing Pigeon ◽  
Genetic Mechanism ◽  
Whole Genome ◽  
Genome Resequencing ◽  
Homing Pigeons ◽  
Rock Pigeon ◽  
Whole Genome Resequencing

Abstract Objective Navigation is the most important feature of homing pigeons, however no integrated response to genetic mechanism of navigation has been reported. The generated data herein represent whole-genome resequencing data for homing pigeon and three other breeds of rock pigeons. Selective sweep analysis between homing pigeon and other breeds of rock pigeon can provide new insight about identification of candidate genes and biological pathways for homing pigeon ability. Data description Whole-genomes sequence data related to 95 birds from four breeds of rock pigeons including, 29 feral pigeons, 24 Shiraz tumblers, 24 Persian high flyers and 18 homing pigeons were provided. More than 6.94 billion short reads with coverage (average ≈7.50 x) and 407.1 Gb data were produced. Whole genome sequencing was carried out on the Illumina Hiseq 2000 platform using a 350 bp library size and 150 bp paired-end read lengths. The whole genome sequencing data have been submitted at the NCBI SRA Database (PRJNA532675). The presented data set can provide useful genomic information to explain the genetic mechanism of navigation ability of homing pigeons and also testing other genetic hypothesis by genomic analysis.

Recognition of Familiar Visual Landmarks in Homing Pigeons

1993 ◽  
Vol 46 (3) ◽  
pp. 371-375 ◽  
Author(s):  
V. A. Braithwaite ◽  
T. C. Guilford
Keyword(s):  
Release Site ◽  
Columba Livia ◽  
Relative Importance ◽  
Visual Landmarks ◽  
Homing Pigeons ◽  
Homing Behaviour ◽  
Similar Improvement ◽  
Current Location

It is now well established that homing pigeons (Columba livia) use a variety of mechanisms and cues to help them find their way home. It is far more difficult to determine the relative importance attached to such mechanisms and cues by pigeons during homing. As a step towards this quantitative stage in our understanding of homing behaviour we consider if cues contribute significantly to homing speed. In particular we attempt to assess the role of visual landmarks. Using pigeons released from familiar release sites, we demonstrate that birds home faster if they can view their surroundings from inside a Perspex box for 5 minutes prior to being released, compared to birds denied this view. Pigeons released from unfamiliar sites, however, do not show a similar improvement. We suggest that seeing familiar visual landmarks before release allows pigeons to become more certain of their current location with respect to home. Simply viewing the release site is not sufficient to produce a faster homing speed; the pigeons must be able to recognize that the release site is familiar.

scholarly journals Misinformed leaders lose influence over pigeon flocks

2016 ◽  
Vol 12 (9) ◽  
pp. 20160544 ◽  
Author(s):  
Isobel Watts ◽  
Máté Nagy ◽  
Theresa Burt de Perera ◽  
Dora Biro
Keyword(s):  
Decision Making ◽  
Columba Livia ◽  
Collective Decision ◽  
Collective Decision Making ◽  
Homing Pigeons ◽  
Inaccurate Information ◽  
Collective Decisions ◽  
Adaptive Consequences ◽  
Informed Group ◽  
Influential Individuals

In animal groups where certain individuals have disproportionate influence over collective decisions, the whole group's performance may suffer if these individuals possess inaccurate information. Whether in such situations leaders can be replaced in their roles by better-informed group mates represents an important question in understanding the adaptive consequences of collective decision-making. Here, we use a clock-shifting procedure to predictably manipulate the directional error in navigational information possessed by established leaders within hierarchically structured flocks of homing pigeons ( Columba livia ). We demonstrate that in the majority of cases when leaders hold inaccurate information they lose their influence over the flock. In these cases, inaccurate information is filtered out through the rearrangement of hierarchical positions, preventing errors by former leaders from propagating down the hierarchy. Our study demonstrates that flexible decision-making structures can be valuable in situations where ‘bad’ information is introduced by otherwise influential individuals.

Phonology and grammatical morphology in specific language impairment: Accounting for individual variation in English and Italian

1996 ◽  
Vol 17 (1) ◽  
pp. 85-104 ◽  
Author(s):  
Umberta Bortolini ◽  
Laurence B. Leonard
Keyword(s):  
Individual Differences ◽  
Language Impairment ◽  
Individual Variation ◽  
Specific Language Impairment ◽  
Function Words ◽  
Specific Language ◽  
Grammatical Morphology ◽  
Italian Children ◽  
Mean Length Of Utterance

ABSTRACTChildren with specific language impairment (SLI) often show more limited use of grammatical morphology than younger, normally developing children matched according to mean length of utterance (MLU). However, within groups of children with SLI, individual differences are seen in grammatical morpheme use. In this study, we examined the role of weak syllable use in explaining some of these differences. Employing two different languages – English and Italian - children with SLI were placed into pairs. The children in each pair showed similar MLUs; however, one member of the pair showed a greater use of particular function words. In each of the pairs examined in both languages, the children with the greater use of function words also showed a greater use of weak syllables that did not immediately follow strong syllables. The weak syllable productions of children showing a more limited use of function words in each pair seemed to be dependent on a strong syllable-weak syllable production sequence. This sequence appeared to be operative across several prosodic levels, as defined within the framework of prosodic phonology. Because weak syllables that follow strong syllables usually have longer durations than those that precede strong syllables, the findings might have a perceptual basis. However, the results raise the possibility that limitations in prosody can restrict the degree of grammatical morpheme use by children with SLI.

scholarly journals Fine-scale changes in speed and altitude suggest protean movements in homing pigeon flights

2021 ◽  
Vol 8 (5) ◽  
pp. 210130
Author(s):  
Baptiste Garde ◽  
Rory P. Wilson ◽  
Emmanouil Lempidakis ◽  
Luca Börger ◽  
Steven J. Portugal ◽  
...  
Keyword(s):  
Land Cover ◽  
Predation Risk ◽  
High Frequency ◽  
Columba Livia ◽  
Homing Pigeon ◽  
Rate Of Change ◽  
Flight Speed ◽  
Power Curve ◽  
Homing Pigeons ◽  
Perceived Predation Risk

The power curve provides a basis for predicting adjustments that animals make in flight speed, for example in relation to wind, distance, habitat foraging quality and objective. However, relatively few studies have examined how animals respond to the landscape below them, which could affect speed and power allocation through modifications in climb rate and perceived predation risk. We equipped homing pigeons ( Columba livia ) with high-frequency loggers to examine how flight speed, and hence effort, varies in relation to topography and land cover. Pigeons showed mixed evidence for an energy-saving strategy, as they minimized climb rates by starting their ascent ahead of hills, but selected rapid speeds in their ascents. Birds did not modify their speed substantially in relation to land cover, but used higher speeds during descending flight, highlighting the importance of considering the rate of change in altitude before estimating power use from speed. Finally, we document an unexpected variability in speed and altitude over fine scales; a source of substantial energetic inefficiency. We suggest this may be a form of protean behaviour adopted to reduce predation risk when flocking is not an option, and that such a strategy could be widespread.

scholarly journals Zh.T. Toshchenko. Precariat: from protoclass to new class.

2019 ◽  
Vol 89 (11) ◽  
pp. 1176-1179
Author(s):  
Ivan I. Osinsky
Keyword(s):  
Social Class ◽  
Significant Influence ◽  
Social Processes ◽  
Scientific Understanding ◽  
Scientific Concepts ◽  
Scientific Interest ◽  
New Class ◽  
The Subject ◽  
Near Future

Monograph of RAS Corresponding Member Zh.T. Toshchenko is distinguished by the well-known features of the author's research style: a thorough analysis of modern social processes, the identification of new qualities, phenomena, trends and their deep scientific understanding in them. In this case, those phenomena that already have or will begin to exert a significant influence on the essence and appearance of society in the near future fall into focus. The subject of scientific interest Zh.T. Toshchenko had previously faced the problems of a paradoxical person, centaurism, phantoms, ethnocracy, theocracy, the fate of the intelligentsia, etc. An analysis of these topics led the scientist to create original, well-constructed scientific concepts, including the integral concept of the sociology of life [1], which has received scientific recognition community. The new book is dedicated to the precariate - an emerging social class, the place and role of which in the life of modern societies is becoming more tangible.

scholarly journals Fine-scale changes in speed and altitude suggest protean movements in homing pigeon flights

2021 ◽  
Author(s):  
Baptiste Garde ◽  
Rory P. Wilson ◽  
Emmanouil Lempidakis ◽  
Luca Börger ◽  
Steven J. Portugal ◽  
...  
Keyword(s):  
Land Cover ◽  
Predation Risk ◽  
High Frequency ◽  
Columba Livia ◽  
Homing Pigeon ◽  
Rate Of Change ◽  
Flight Speed ◽  
Homing Pigeons ◽  
Substantial Impact ◽  
Perceived Predation Risk

AbstractThe flight speeds that animals should adopt to minimise energy expenditure in different scenarios can be predicted by the curve of power against speed. However, relatively few studies have examined how animals respond to the landscape below them, which could affect speed through modifications in climb rate and perceived predation risk. We equipped homing pigeons (Columba livia) with high frequency loggers to examine how flight speed varies in relation to topography and land cover, predicting that these parameters may have a substantial impact on flight speed and hence cost. Pigeons showed mixed evidence for an energy saving strategy, as they minimised climb rates by starting their ascent ahead of hills, but selected rapid speeds in their ascents. Birds did not modify their speed substantially in relation to land cover, but higher speeds were observed during descending flight, highlighting the importance to consider the rate of change in altitude before estimating power use from speed. Finally, we document an unexpected variability in speed and altitude over fine scales; a source of substantial inefficiency. We suggest this may a form of protean behaviour adopted to reduce predation risk when flocking is not an option, and that such a strategy could be widespread.

Alternation in Government in the Industrialized Countries

1982 ◽  
Vol 17 (1) ◽  
pp. 3-21 ◽  
Author(s):  
Raymond Aron
Keyword(s):  
Industrialized Countries ◽  
Scientific Interest ◽  
The Subject

I MUST CONFESS THAT I DID NOT CHOOSE THE SUBJECT OF this article out of theoretical or scientific interest. My dreams have not been peopled by the merits of replacing one team by another in government. It was FranGois Mitterrand's election to the Presidency of the French Republic to which I reacted in a way that I shall not conceal from you: alternation in government is not in itself a blessing. Let us admit that it is desirable in general and in the abstract that, where a country is divided between two blocs, each of them should some day come to power, one of them should not be condemned to the ungrateful role of a perpetual opposition. But having said that, we should not change government unless the new oneholds out more hope than the old.

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