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Author Rands, S.A.; Cowlishaw, G.; Pettifor, R.A.; Rowcliffe, J.M.; Johnstone, R.A. url  doi
openurl 
  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  
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  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 (down) Equine Behaviour @ team @ Serial 5126  
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Author De Stoppelaire, G.H.; Gillespie, T.W.; Brock, J.C.; Tobin, G.A. doi  openurl
  Title Use of remote sensing techniques to determine the effects of grazing on vegetation cover and dune elevation at Assateague Island National Seashore: impact of horses Type Journal Article
  Year 2004 Publication Environmental Management Abbreviated Journal Environ Manage  
  Volume 34 Issue 5 Pages 642-649  
  Keywords Animals; Animals, Wild; Conservation of Natural Resources; Ecosystem; Environmental Monitoring; *Feeding Behavior; *Horses; Maryland; Plants/*growth & development; Population Dynamics; Silicon Dioxide; *Soil  
  Abstract The effects of grazing by feral horses on vegetation and dune topography at Assateague Island National Seashore were investigated using color-infrared imagery, lidar surveys, and field measurements. Five pairs of fenced and unfenced plots (300 m2) established in 1993 on sand flats and small dunes with similar elevation, topography, and vegetation cover were used for this study. Color-infrared imagery from 1998 and field measurements from 2001 indicated that there was a significant difference in vegetation cover between the fenced and unfenced plot-pairs over the study period. Fenced plots contained a higher percentage of vegetation cover that was dominated by American beachgrass (Ammophila breviligulata). Lidar surveys from 1997, 1999, and 2000 showed that there were significant differences in elevation and topography between fenced and unfenced plot-pairs. Fenced plots were, on average, 0.63 m higher than unfenced plots, whereas unfenced plots had generally decreased in elevation after establishment in 1993. Results demonstrate that feral horse grazing has had a significant impact on dune formation and has contributed to the erosion of dunes at Assateague Island. The findings suggest that unless the size of the feral horse population is reduced, grazing will continue to foster unnaturally high rates of dune erosion into the future. In order to maintain the natural processes that historically occurred on barrier islands, much larger fenced exclosures would be required to prevent horse grazing.  
  Address US Geological Survey, Center for Coastal and Watershed Studies, St. Petersburg, Florida 33701, USA. georgia.destoppelaire@my.FWC.com  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0364-152X ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15633024 Approved no  
  Call Number (down) Serial 1896  
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Author Cambefort, J.P. openurl 
  Title A comparative study of culturally transmitted patterns of feeding habits in the chacma baboon Papio ursinus and the vervet monkey Cercopithecus aethiops Type Journal Article
  Year 1981 Publication Folia Primatologica; International Journal of Primatology Abbreviated Journal Folia Primatol (Basel)  
  Volume 36 Issue 3-4 Pages 243-263  
  Keywords Age Factors; Animals; *Cercopithecus; *Cercopithecus aethiops; Culture; *Feeding Behavior; Female; Group Structure; Learning; Male; *Papio; Social Class; Teaching  
  Abstract Japanese workers have studied social acquisition patterns of new feeding habits in Macaca fuscata which they have termed precultural. The present study investigates the same phenomenon in the chacma baboon and the vervet monkey in their natural habitat. The questions addressed are: (1) How a new feeding habit enters a troop and by which age and sex category, also how it is propagated? (2) When individuals are permitted with a choice between palatable and unpalatable food, can they learn by demonstration only or do they have to pass through a direct learning process? (3) Can the results from the above questions be explained by social parameters such as the social structure of the individual species? It was found that juvenile baboons discover new food and that after the discovery propagation is instantaneous. In vervets discovery is random among the age classes and propagation is slow and takes place through certain 'pivot' individuals. Both species fail to learn about palatability by demonstration but have to go through a direct learning process. This contrasts strongly with the forest baboon Mandrillus sphinx that have been shown to learn by demonstration. Socially, baboon juveniles stay closer to each other than the adults who force them to live at the periphery of the troop. Vervets again forage without precise sub-group formation. The link between social and cultural propagation and social structure is discussed on the basis of these findings.  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0015-5713 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:7319426 Approved no  
  Call Number (down) Serial 2087  
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Author Gauvin, S.; Giraldeau, L.-A. doi  openurl
  Title Nutmeg mannikins ( Lonchura punctulata) reduce their feeding rates in response to simulated competition Type Journal Article
  Year 2004 Publication Oecologia Abbreviated Journal Oecologia  
  Volume 139 Issue 1 Pages 150-156  
  Keywords Animals; *Feeding Behavior; Population Density; *Social Behavior; *Songbirds  
  Abstract Group feeding animals experience a number of competitive foraging costs that may result in a lowered feeding rate. It is important to distinguish between reductions in feeding rates that are caused by reduced food availability and physical interactions among foragers from those caused by the mere presence of foraging companions that may be self-imposed in order to obtain some benefit of group membership. Starlings ( Sturnus vulgaris) reduce their feeding rates when in the company of simulated competitors located in an adjacent cage that cannot affect the food availability or interact with the forager. In the present study, we investigate whether the presence of simulated competitors in another species of passerine, nutmeg mannikins ( Lonchura punctulata), can result in self-imposed reductions in feeding rates. When feeding in the company of simulated competitors, mannikins spent more non-foraging time near them, fed more slowly, reduced travel times between patches, reduced their scanning time and pecked more slowly. These results provide evidence that simulated competitors induce a reduction in pecking rate: behavioural interference. These self-imposed responses to competitors may have resulted from attempts to remain close to the non-feeding companions. Such self-imposed reductions in feeding rates may be a widespread yet generally unrecognised foraging cost to group feeding individuals.  
  Address Department of Biology, Concordia University, Montreal, Quebec, Canada  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0029-8549 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:14722748 Approved no  
  Call Number (down) Serial 2133  
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