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The importance of predator behaviour on risk to prey

By Christos Ioannou


Both predator and prey have evolved to maximise reproductive success by balancing food intake with risk. There has been a bias in predator-prey studies, where prey\ud behaviour has been examined in detail, yet predators are assumed to follow simplistic rules. I use three-spined sticklebacks predating upon invertebrate prey to test a range of ways in which prey risk was hypothesised to be affected by predator behaviour.\ud \ud The relationship between encounter rate and prey density has been recently shown not to be directly proportional, and theoretical arguments have been made that predator search behaviour can explain this trend. I test these arguments, and show acceleration of a predator's search path can in fact lead to the observed less-than-directly proportional relationship between prey density and encounter rate.\ud \ud The perceptual constraints of predators can have major impacts on prey risk. Once encountered, an attack was more likely when prey were encountered late in a search, probably due to a decrease in anti-predator vigilance as the fish became more habituated to the arena. In a subsequent study, larger groups of prey were more quickly found, as were larger numbers of groups. This led to the conclusion that the field of attention is a subset of the total visual field, and this is also supported by denser prey being more conspicuous.\ud \ud Although the predator responded to increased prey group size and density with a reduced time to detect and attack prey, attacks on such groups were less successful due to the confusion effect. Interestingly, I show the effect of prey density to be sensitive to spatial scale, where a large-scale measure of density affected conspicuousness and a small-scale measure affected attack success. This was\ud explained by a reduction in the total number of prey in the visual field as a group of prey is approached and attacked.\ud \ud In the final chapter, I turn my attention to differences in temperament within a predator population, and how this affects prey risk. As expected, bolder fish represented a greater risk to the prey. However, as larger fish tended to be more bold, suggesting boldness was driven by their perception of predation risk, a within community behaviourally-mediated trophic cascade may occur. where the risk to prey is driven by their predators' own perceived risk of predation. This shows that optimal foraging decisions under the threat of predation, as well as perceptual constraints, can mediate the effect of predator behaviour on prey risk.\ud \u

Publisher: Institute of Integrative and Comparative Biology (Leeds)
Year: 2008
OAI identifier: oai:etheses.whiterose.ac.uk:275

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  1. (1988). A fitness cost of foraging in the guppy. doi
  2. (1992). A Functional Biology of Sticklebacks. doi
  3. (1984). A laboratory simulation of foraging behavior: The effect of search rate on the probability of detecting prey. doi
  4. (1984). A predator's cost of overcoming the confusion-effect of swarming prey. doi
  5. (1988). A risk-balancing trade off between foraging rewards and predation hazard in a shoaling fish. doi
  6. (2005). Adaptive behaviour of chironomid larvae (Chironomus riparius) in response to chemical stimuli from predators and resource density. doi
  7. (1999). Aggregation behaviour of Bqfo maculatus týl as an antipredator mechanism. doi
  8. (2006). An allometric vision and motion model to predict prey encounter rates.
  9. (1967). An experiment on spacing-out as a defence against predation. doi
  10. (1986). Attack Abatement: A model for zroup protection by combined avoidance and dilution. doi
  11. (2004). Avoiding Attack. doi
  12. (1987). Bat predation and its influence on calling behaviour in neotropical katydids. doi
  13. (2004). Behavioral syndromes: an ecological and evolutionary overview. doi
  14. (2002). Behavioural and ecological consequences of limited attention. doi
  15. (1990). Behavioural decisions made under the risk of predation: A review and prospectus. doi
  16. (1979). Can an experienced predator overcome the confusion of swarming prey more easily? doi
  17. (2004). Central assumptions of predator-prey models fail in a semi-natural experimental system. doi
  18. (2000). Chance in biology: using probability to explore I nature. doi
  19. (1999). Chemical mimicry and host specificity in the butterfly Maculinea rebeli, a social parasite of Myrmica ant colonies. doi
  20. (1978). Clumping versus spacing out: experiments on nest predation in fieldfares (Turdus pilaris). doi
  21. (2007). Confusion of predators does not rely on specialist coordinated behaviour. doi
  22. (2004). Correlates of boldness in three-spined sticklebacks (Gasterosteus aculeatus). doi
  23. (2006). Crypsis versus intimidation - anti-predation defence in three closely related butterflies. doi
  24. (1997). Dens ity-dependent predation by skunks using olfactory search images. doi
  25. (1995). Density dependence and numerosity in fright stimulated aggregation behaviour of shoaling fish. doi
  26. (1996). Density dependence: are we searching at the wrong spatial scale? doi
  27. (2007). Density effects at multiple scales in an experimental plant population. doi
  28. (1973). Detection of prey flocks by predators. doi
  29. (1994). Differential fitness returns to spatial positions in groups. doi
  30. (2005). Effects of predator confusion on functional responses. doi
  31. (1997). Experimental evidence for a behavior-mediated trophic cascade in a terrestrial food chain. doi
  32. (1977). Experiments on selection by predators against spatial oddity of their prey. doi
  33. (1974). Experiments on whether schooling by their prey affects the hunting behaviour of cephalopods and fish predators. doi
  34. (2001). Explaining leptokurtic movement distributions: intrapopulation variation in boldness and exploration. doi
  35. (2004). Faced with a choice, sparrowhavvks more often attack the more vulnerable prey group. doi
  36. (1989). Finch flock size and the risk of hawk predation at a migrator-. N stopover site.
  37. (1994). Fish and game -A game-theoretic approach to habitat selection by predators and prey. doi
  38. (1982). Fish vision and the detection of planktonic prey. doi
  39. (1994). Fish-enhanced patchiness in Daphnia distribution.
  40. (2004). Fitness consequences of avian personalities in a fluctuating environment. doi
  41. (1994). Flocking is an effective anti-predation strategy in redshanks. Tringa totanus. doi
  42. (1962). Food selection in finches with special reference to interspecific differences. doi
  43. (1998). Game theory and predator-prey response races. In: Dugatkin LA, Reeve HK (eds) Advances in game theory and the study of animal behaviour.
  44. (2004). Geometry for mutualistic and selfish herds: the limited domain of danger. doi
  45. (1982). Group size and anti-predatory strategies in a marine insect.
  46. (1991). Group size and predation risk: a field analysis of encounter and dilution effects. doi
  47. (1995). Groups confuse predators by exploiting perceptual bottlenecks: a connectionist model of the confusion effect. doi
  48. (2005). Host-parasitoid spatial ecology: a plea for a landscape-level synthesis. doi
  49. (2005). In situ examination of boldnessshyness traits in the tropical poeciliid, Brachyraphis episcopi. doi
  50. (2005). Increasing search rate over time may cause slower than expected increase in prey encounter rate with increasing prey density. doi
  51. (1996). Influence of prey foraging posture on flight behavior and predation risk: predators take advantage of unwary prey. Behavioral r, - r-cologv 7: doi
  52. (2005). Information and its use by animals in evolutionary ecology. doi
  53. (1996). Insect motion detectors matched to visual ecology. doi
  54. (2007). Integrating animal temperament within ecology and evolution. doi
  55. (1995). Interaction between food availabilltv and predation mortalit), mediated bý, adaptive behavior. doi
  56. (2008). Interaction ruling animal collective behavior depends on topological rather than metric distance: Evidence from a field study. doi
  57. (2002). Living in Groups. doi
  58. (2007). Macrophyte refuges, prey behaviour and trophic interactions: consequences for lake water claritý'. doi
  59. (2003). Marginal predation methodologies and the importance of predator preferences. doi
  60. (2008). Mechanisms for aggregation in animals: Rule success depends on ecological variables. doi
  61. (1997). Mortality risk of spatial positions in animal groups: The danger of being in the front. doi
  62. (2001). Multiple benefits of gregariousness cover detectability costs in aposernatic aggregations. doi
  63. (2003). Natal dispersal and personalities in great tits (Parus major). doi
  64. (1986). Oddity and the 'confusion effect' in predation. doi
  65. (2003). Odor localization requires visual feedback during free flight in Drosoplila melanogaster. doi
  66. (1975). Omnivorous zooplankton and planktiN-orous doi
  67. (1970). On territorial behaviour and other factors influencing habitat distribution in birds. 1. Theoretical development. doi
  68. (2001). Optimal diet theory: when does it work, and when and why does it fail? doi
  69. (1979). Optimal foraging of sticklebacks on swarming prey. doi
  70. (2008). Optimal individual positions in animal groups. doi
  71. (2005). Pairs of extreme personalities have highest reproductive success. doi
  72. (1988). Parasitoid theory: From aggregation to dispersal. doi
  73. (1986). Patch choice under perceptual constraints: a cause for departures from an ideal free distribution. doi
  74. (1999). Patterns of herbivore incidence on experimental arrays and field populations of ragwort, doi
  75. (1976). Predation and kleptoparasitism by skuas in a Shetland seabird colony. doi
  76. (1978). Predation and the evolution of gregariousness. 1. Models for concealment and evasion. doi
  77. (1968). Predation by the three-spined stickleback (Gasterosteaus aculeatus L. ): the influence of hunger and experience. doi
  78. (2007). Predation risk affects reproductive physiology and dernography of elk. doi
  79. (2006). Predation risk as a driving force for sexual segregation: A cross-population comparison. doi
  80. (2002). Predator evasion in Daphnia: the adaptive value of aggregation associated with attack abatement. doi
  81. (1995). Predator preferences for attacking particular prey group sizes: consequences for predator hunting success and prey predation risk. doi
  82. (2003). Predator- induced selection on temperament in bighom ewes.. doi
  83. (2007). Predator-prey encounter rates in freshwater piscivores: effects of prey density and Nvater transparency. doi
  84. (2007). Prey swarming: which predators become confused and why? doi
  85. (1972). Prey-catching behaviour in the sparrow hawk. doi
  86. (1987). Provenance, shoal size and socio-biology of predator-evasion behaviour in minnow shoals. doi
  87. (2004). Public information: from nosy neighbors to cultural evolution. doi
  88. (2002). Putting predators back into behavioural predator-prey interactions. doi
  89. (2002). Quantitative analysis of fiddler crab flock movement: evidence for 'selfish herd' behaviour. doi
  90. (1998). Refuge use bN fish as a function of body length-related metabolic expenditure and predation risks. doi
  91. (1998). Responses of wild birds to novel prey: Evidence of dietary conservatism. doi
  92. (1997). Restricted attentional capacity within but not between sensory modalities. doi
  93. (1983). Searching for cryptic prey: The effect of search rate. doi
  94. (2008). Searching for prey - the effect of group size and number. doi
  95. (1994). Shyness and boldness in humans and other animals. doi
  96. (1998). Shyness and boldness in pumpkinseed sunfish: individual differences are context-specific. doi
  97. (1997). Size-selective mortality in the juvenile stage of teleost fishes: a review.
  98. (1959). Some characteristics of simple types of predation and parasitism. doi
  99. (2005). Spatial distribution of dominant animals within a group: comparison of four statistical tests of location. doi
  100. (2005). Spatial processes can deten-nine the relationship between prey encounter rate and prey density. doi
  101. (1998). Stress and decision making under the risk of predation: Recent developments from behavioral, reproductive, and ecological perspectives. doi
  102. (1983). Studies on the natural enemy complex of the holly leaf-miner: The effects of scale on the detection of aggregative responses and the implications for biological control. 01kos 40: doi
  103. (2005). The adaptive significance of colouration in mammals. doi
  104. (2008). The confusion effect -from neural networks to reduced predation risk. doi
  105. (2006). The confusion effect in predatory neural networks. doi
  106. (1996). The dynamics and scaling of foraging velocity and encounter rate iri ZD tý t-D mammalian herbivores. doi
  107. (1993). The effect of 'Schreckstoff on the shoaling behaviour of the minnow -a test of Hamilton's selfish herd theory. doi
  108. (1999). The effect of group size on the foraging behaviour t-ý : _:, of juvenile coho salmon: reduction of predation risk or increased competition? doi
  109. (1999). The effect of prey mobility, prey contrast, turbidity and spectral composition on the reaction distance of Gob iusculus. flavescens to its planktonic prey. doi
  110. (2005). The effects of group size, shape and composition on ease of detection of cryptic prey. doi
  111. (1976). The Ethology of Predation. doi
  112. (1965). The functional response of predators to prey density and its role in mimicry amd population regulation. doi
  113. (1998). The influence of density on frequency-dependent selection by wild birds feeding on artificial prey. doi
  114. (1974). The influences of encountering a food object on subsequent searching behavior in Gasterosteus aculeatus L. doi
  115. (1994). The mechanism of aggregation behaviour in fish shoals: individuals minimize approach time to neighbours. doi
  116. (1960). The natural control of insects in pine woods. 1. Factors influencing the intensity of predation by songbirds.
  117. (1960). The normal feeding behaviour of the three-spined stickleback (Gasterosteus aculeatus, doi
  118. (2006). The representation of perceived angular size in human primary visual cortex. doi
  119. (1994). The unselfish swarm? doi
  120. (2000). Theory and methods in studies of vigilance and aggregation. doi
  121. (2000). Ultraviolet N, ision in birds.
  122. Verhandlungen Internationale Vereinigungfür theoretische und angewandte
  123. (1982). Vertical migration of zooplankton: a game between predator and prey. doi
  124. (2002). Visual predators select for crypticity and polymorphism in virtual prey. doi

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