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STARLINGS EXPLOITING PATCHES: THE EFFECT OF RECENT EXPERIENCE ON FORAGING DECISIONS. Innes C. Cuthill, Alejandro Kacelnik, John R. Krebs, Patsy Haccou & Yoh Iwasa Anim. Behav., 1990, 40, 625-640. Introduction – Background.
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STARLINGS EXPLOITING PATCHES: THE EFFECT OF RECENT EXPERIENCE ON FORAGING DECISIONS Innes C. Cuthill, Alejandro Kacelnik, John R. Krebs, Patsy Haccou & Yoh Iwasa Anim. Behav., 1990, 40, 625-640
Introduction – Background • Model of rate maximization→ the average number of prey taken per visit • Starlings past experience of travel times→ adjust the number of prey taken
Introduction – Question • Howstarlings respond to short-term changes in travel time within an experimental session? • Recent experience of travel times influencesnumber of prey taken per visit
Experiment 1General methods Feeding Area Travel Area
Apparatus Green light off Green light off 鳥離開 Feeder perch In the “patch” Feeder perch Hops (h=exp(G/1.5)) 1, 3, 7, 14, 28, … Feeder 2 sec 停在其中一個travel perch 達到目標 5 or 60次 Red light (2) on All lights off The other side of green light on 綠色燈交替開關引導達成目標 Red light (1) on Green light on
Experiment 1 △: bird 0; ○: bird 1;●: bird 2; ◇: bird 3;■: bird 4;□: bird 5
Experiment 1 : short travel requirements □: longtravel requirements ■: predicted prey per visit following shorttravel requirement +: predicted following long travelrequirement
Experiment 1 conclusion • The birds’ behavior based only on the most recent travel time WHY??
Experiment 1 conclusion • Test the hypothesis that the results of experiment 1 are caused by digestive constraint : short travel requirements □: longtravel requirements ■: predicted prey per visit following shorttravel requirement +: predicted following long travelrequirement
Experiment 2 △: bird 0; ○: bird 1;●: bird 2; ◇: bird 3;■: bird 4;□: bird 5
Experiment 2 : short travel requirements □: longtravel requirements
Cnclusion • Non-adaptive behavior hypothesis • Interruptions to foraging • Use of recent experience • Alternative currencies