|   | 
Details
   web
Records
Author (up) Pettifor, R.A.
Title The effects of avian mobbing on a potential predator, the European kestrel, Falco tinnunculus Type Journal Article
Year 1990 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.
Volume 39 Issue 5 Pages 821-827
Keywords
Abstract European kestrels were observed being mobbed by other birds on 63 occasions. Eleven species were involved, and in two instances mobs were composed of more than one species. Both flight-hunting and perch-hunting kestrels flew significantly further between their foraging positions when they were mobbed than when they were not mobbed; on average, mobbing resulted in flight-hunting kestrels moving 6[middle dot]8 times, and perch-hunting kestrels 2[middle dot]7 times, the mean distances moved by non-mobbed birds. The mean strike distance of perch-hunting kestrels attempting to capture birds was significantly less than the distance between perches flown by perch-hunting kestrels when mobbed. These data provide quantitative support for the assumption that mobbing causes a predator to vacate its immediate foraging area. The activity of the kestrels also influenced the frequency that they were mobbed, with kestrels that were flight-hunting being mobbed more than expected compared with ones that were perch-hunting. Kestrels were observed being mobbed throughout the year, and there was no discernible difference in their response to mobbing between seasons. These results are discussed in relation to current ideas on the functions of avian mobbing.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 4091
Permanent link to this record
 

 
Author (up) Rands, S.A.; Cowlishaw, G.; Pettifor, R.A.; Rowcliffe, J.M.; Johnstone, R.A.
Title The emergence of leaders and followers in foraging pairs when the qualities of individuals differ Type Journal Article
Year 2008 Publication BMC Evolutionary Biology Abbreviated Journal BMC Evol Biol
Volume 8 Issue Pages 51
Keywords Animals; *Feeding Behavior; *Food Chain; *Models, Biological; *Social Dominance
Abstract BACKGROUND: Foraging in groups offers animals a number of advantages, such as increasing their likelihood of finding food or detecting and avoiding predators. In order for a group to remain together, there has to be some degree of coordination of behaviour and movement between its members (which may in some cases be initiated by a decision-making leader, and in other cases may emerge as an underlying property of the group). For example, behavioural synchronisation is a phenomenon where animals within a group initiate and then continue to conduct identical behaviours, and has been characterised for a wide range of species. We examine how a pair of animals should behave using a state-dependent approach, and ask what conditions are likely to lead to behavioural synchronisation occurring, and whether one of the individuals is more likely to act as a leader. RESULTS: The model we describe considers how the energetic gain, metabolic requirements and predation risks faced by the individuals affect measures of their energetic state and behaviour (such as the degree of behavioural synchronisation seen within the pair, and the value to an individual of knowing the energetic state of its colleague). We explore how predictable changes in these measures are in response to changes in physiological requirements and predation risk. We also consider how these measures should change when the members of the pair are not identical in their metabolic requirements or their susceptibility to predation. We find that many of the changes seen in these measures are complex, especially when asymmetries exist between the members of the pair. CONCLUSION: Analyses are presented that demonstrate that, although these general patterns are robust, care needs to be taken when considering the effects of individual differences, as the relationship between individual differences and the resulting qualitative changes in behaviour may be complex. We discuss how these results are related to experimental observations, and how the model and its predictions could be extended.
Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. sean.rands@bristol.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1471-2148 ISBN Medium
Area Expedition Conference
Notes PMID:18282297 Approved no
Call Number Equine Behaviour @ team @ Serial 5126
Permanent link to this record
 

 
Author (up) Rands, S.A.; Cowlishaw, G.; Pettifor, R.A.; Rowcliffe, J.M.; Johnstone, R.A.
Title Spontaneous emergence of leaders and followers in foraging pairs Type Journal Article
Year 2003 Publication Nature Abbreviated Journal Nature
Volume 423 Issue 6938 Pages 432-434
Keywords Animals; *Energy Metabolism; Food; *Food Chain; *Models, Biological; Motor Activity; *Social Behavior; Time Factors
Abstract Animals that forage socially often stand to gain from coordination of their behaviour. Yet it is not known how group members reach a consensus on the timing of foraging bouts. Here we demonstrate a simple process by which this may occur. We develop a state-dependent, dynamic game model of foraging by a pair of animals, in which each individual chooses between resting or foraging during a series of consecutive periods, so as to maximize its own individual chances of survival. We find that, if there is an advantage to foraging together, the equilibrium behaviour of both individuals becomes highly synchronized. As a result of this synchronization, differences in the energetic reserves of the two players spontaneously develop, leading them to adopt different behavioural roles. The individual with lower reserves emerges as the 'pace-maker' who determines when the pair should forage, providing a straightforward resolution to the problem of group coordination. Moreover, the strategy that gives rise to this behaviour can be implemented by a simple 'rule of thumb' that requires no detailed knowledge of the state of other individuals.
Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. s.rands@zoo.cam.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836 ISBN Medium
Area Expedition Conference
Notes PMID:12761547 Approved no
Call Number Equine Behaviour @ team @ Serial 5138
Permanent link to this record