PSYC 311 1st EditionLecture 13March 5 – Predator – Anti-Predator **Obtaining food and avoiding becoming food I. Evolution of Predator/Prey Relations a. Adaptation – inherent capability of a species to adapt to circumstantial change in a manner that increases survivability for that species i. ESS – successful adaptive strategies (camouflage)1. Convergent – strategies that work a. Leaf cutter ants (harvest leaves to plant and grow mushrooms)b. Dentition – similarities of teeth of predators as convergent evolution i. Predacious felines replaced saber tooth tigers – more efficient teeth; sever spinal cords c. Turtle shells, horns/antlers 2. Divergent – Darwin’s finches a. Diverged to fill unfilled ecological niches (adaptive radiation)b. Those that occupy various mainland ecological niches will be more efficient; each niche filled by a different species II. Prey Behaviors a. A species typically has one well developed anti-predator behaviori. Optimal in terms of cost/benefit rationii. Several backupsb. Species with diverse genetic endowment that provides a hierarchy of several defenses i. More likely to surviveii. Predator avoidant behaviors often overlap 1. Warning vs. advertising vs. mimicry III. Strategies to avoid being eaten a. Avoiding detection by predatori. Animal remaining motionless ii. Example: zerbras; camouflageiii. Body decorations: attaching material to body for camouflage b. Warnings – aposematism i. Signals that warn of potential danger to predators1. Example: arrow frogs; bright colors; lose toxicity if taken out of environment 2. Example: blue ringed octopus; related to surprisec. Mimicry – adopting properties of another animal i. Different types – Batesian, Mullerian, Mertensian 1. Example: sea krait octopus with arms that mimic poisonous sea snakes ii. Distraction – used to confuse predators; misdirection 1. Deception on where the head is; so that the prey can still get away iii. Example: hog nose snakes, opossums, fish will “play dead” if other defenses fail d. Terminating Pursuit – escaping i. Antelope stotting (jumping)1. Show off; “I’m fit”; better view point; alarm to other antelope; confusion; social cohesion 2. Correct hypothesis – advertising alarm state and fitness e. Detection and Vigilance – sensory capabilities in prey have evolved to provide optimal predator detection (vision, hearing, smell)i. Safe distance learning – cost/benefit analyses for predator and prey 1. Example: lions are fast but some prey are faster – how close is too close?f. Use of a Sentry – ducks, zebras, meerkats, monkeys i. Lookout: on alert for predators; warning cries g. Interspecies Cooperative Vigilance i. Relationshipii. Usually of a common predator1. Example: rhinos and tickbirds; rhinos protect birds, birds keep rhinos clean 2. Example: baboons and antelopes respond to each other’s warning cries h. Group Defense – protective circles, mobbing, stampedesi. Herds, schooling, flocking ii. Balancing act for group size, regarding