From Compromise to Leadership in Pigeon Homing

Abstract

A central problem faced by animals traveling in groups is how navigational decisions by group members are integrated, especially when members cannot assess which individuals are best informed or have conflicting information or interests . Pigeons are now known to recapitulate faithfully their individually distinct habitual routes home , and this provides a novel paradigm for investigating collective decisions during flight under varying levels of interindividual conflict. Using high-precision GPS tracking of pairs of pigeons, we found that if conflict between two birds' directional preferences was small, individuals averaged their routes, whereas if conflict rose over a critical threshold, either the pair split or one of the birds became the leader. Modeling such paired decision-making showed that both outcomes-compromise and leadership-could emerge from the same set of simple behavioral rules. Pairs also navigated more efficiently than did the individuals of which they were composed, even though leadership was not necessarily assumed by the more efficient bird. In the context of mass migration of birds and other animals, our results imply that simple self-organizing rules can produce behaviors that improve accuracy in decision-making and thus benefit individuals traveling in groups .

Leadership, consensus decision making and collective behaviour in humans

“…They also found that the temporary splitting of groups could allow individuals to avoid following majority decisions that did not favour them. Biro et al (2006) provided further support for Couzin et al (2005); finding that when differences between the directional preferences of two homing pigeons were small, they would average over these preferences, but when differences were large, one of the birds would become leader. Here, we look more specifically at the role of uninformed individuals and demonstrate that both the presence of uninformed individuals and group size can affect the speed with which a group decides between two opposing directional preferences and the likelihood of group fission.…”

“…However, when individual differences are large (more than 1208) then the group decides in favour of one set of informed individuals. This prediction has received empirical support from work on pairs of homing pigeons, C. l. domestica (Biro et al 2006). tested some of the predictions of the Couzin et al (2005) model using small human groups.…”

“…Evidence of leadership behaviour has been found in a number of vertebrate species across a range of taxa, including ungulates (Leicester sheep, Ovis aries; Squires & Daws 1975; sable antelope, Hippotragus niger: Stine et al 1982; Charolais heifers, Bos taurus; Dumont et al 2005; zebras, Equus burchellii: Fischhoff et al 2007), primates (gorillas, Gorilla gorilla beringei : Fossey 1972; chimpanzees Pan troglodytes : Wilson 1980), canids (bush dogs Speothos venaticus : Macdonald 1996; wolves Canis lupus: Peterson et al 2002), birds (bar headed geese Anser indicus: Lamprecht 1992; zebra finches Taeniopygia guttata: Beauchamp 2000; homing pigeons Columba livia domestica: Biro et al 2006) and fishes (roach Rutilus rutilus: Bumann et al 1997; golden shiners Notemigonus crysoleucas : Reebs 2000: Reebs , 2001. In some species, it has been shown that groups tend to be led by dominant individuals (gorillas G. g. beringei : Fossey 1972;Leicester sheep, Squires & Daws 1975; chimpanzees P. troglodytes : Wilson 1980; sable antelope H. niger: Stine et al 1982;bush dogs S. venaticus: Macdonald 1996; wolves C. lupus: Peterson et al 2002).…”

Group decisions in humans and animals: a survey

“…For example, in the European Council of Ministers, larger countries have greater voting weight than smaller countries. In animal groups, hungrier group members can gain more influence on group movement directions than well-fed members (Krause et al 1992; (King et al 2008) travelling start in dolphins (Lusseau & Conradt in press) at least partially shared cohesive group movements in small groups of birds (Black 1988;Biro et al 2006), carnivores (Gompper 1996), ungulates (Conradt & Roper 2003) and primates (Stewart & Harcourt 1994;Boinski & Campbell 1995;Byrne 2000;Milton 2000) cohesive group movements in large swarms of insects (Buhl et al 2006), shoals of fishes ( Ward et al 2008), flocks of birds ( Wallraff 1978;Simons 2004) or herds of ungulates (Prins 1996) group activity synchronization (Conradt 1998;Ruckstuhl 1998Ruckstuhl , 1999 nest-site choice in eusocial insects (Seeley & Buhrman 1999;Franks et al 2009) and bats (Kerth et al 2006) coordination of cooperative hunts (Courchamp et al 2002) What matters in this game is that they both choose the same strategy (a biological example would be reproductive synchronization). If they fail to coordinate, they both receive nothing.…”

Group performance is maximized by hierarchical competence distribution

“…G roup life involves a continuous series of collective decision-making events related to a large selection of tasks [1][2][3] , such as searching for food 4 , navigating towards a distant target [5][6][7][8] or deciding when and where to go 7,9 . The members of a group typically contribute to finding the best solution with varying degrees of input, because of the engineered or naturally occurring differences in their capabilities of possessing information 1,[10][11][12][13][14][15][16] .…”