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Behavioral ecology examines the ecological and evolutionary factors influencing animal behavior. This includes fixed action patterns – sequences of innate behaviors that are triggered by specific stimuli. For example, geese will persistently attempt to retrieve an egg if it is removed from their nest. The course also addresses environmental signals in both animals and plants, the significance of melatonin in circadian rhythms, and communication methods such as the waggle dance of bees. It further explores the interplay of nature and nurture in behavior, illustrated through various studies and examples.
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Behavioral ecology is the study of the ecological and evolutionary basis for animal behavior
A fixed action pattern a sequence of unlearned, innate behaviors that is unchangeable • Once initiated, it is usually carried to completion • triggered by an external cue, a sign stimulus https://www.youtube.com/watch?v=ZfcGZCGdGVE&list=PL4C2DAEF2C65122DE
http://www.youtube.com/watch?v=vUNZv-ByPkU • Fixed Action Pattern in Geese: • If an egg is taken from them they will not stop until it is returned, ‘head bobbing motion’ to roll egg back to nest.
What role does the environment play in signaling? • Phototropism – growth of a plant towards (+) or away (-) from light http://plantsinmotion.bio.indiana.edu/plantmotion/movements/tropism/phototropism/corn/cornworship.html
Circadian Rhythms • Process that follows a routine 24 hour cycle • What is the signal? https://www.youtube.com/watch?v=mUwbbLZANVE
Photoperiodism • A physiological response to the relative lengths of day and night
Brain makes melatonin • When there is less light, the SCN tells the brain to make more melatonin so you get drowsy.
Jet lag • What is the signal?
Monarch Migration • The navigation of the fall migration of the Monarchs to their overwintering grounds in central Mexico uses a "sun compass" that depends upon a circadian clock in their antennae. https://www.youtube.com/watch?v=x0m_rK_WpjQ
Animal Signals and Communication • signal is a behavior that causes a change in another animal’s behavior • Communication is the transmission and reception of signals
Fruit fly courtship • http://www.hhmi.org/biointeractive/fruit-fly-courtship
Figure 39.16 A C B Location B Location C Waggle Dance • A bee returning from the field performs a dance to communicate information about the distance and direction of a food source (b) Round dance (food near) (a) Worker bees (c) Waggle dance (food distant) 30 30 Beehive Location A http://video.nationalgeographic.com/video/weirdest-bees-dance
Nature vs. Nuture • what behaviors are genetically based and what is learned (Nature vs. Nurture) Serial Killer, Ted Bundy Is a serial killer born that way?
Dogs Decoded: At 31 Minutes: http://www.youtube.com/watch?v=yN96Gid6Kjo Cross-fostering Exp Table 39.2 • CA mice: aggressive, lots parental care • White-footed mice: less aggressive, little parental care What can you conclude? Nature vsNuture?
Prey Selection Cross-fostering Exp • Coastal populations feed mostly on banana slugs, while inland populations rarely eat banana slugs • Studies have shown >60% Coastal snakes ate the banana slugs, <20% of inland snakes did Figure 39.25 What can you conclude? Nature vsNuture?
Genetics or Environment? • Twin Studies -Compare identical twins raised apart vs twins raised together
Figure 39.17a Learning • the modification of behavior based on specific experiences • Imprinting • the establishment of a long-lasting behavioral response to a particular individual during a specific time in development, the sensitive period (a) Konrad Lorenz and geese
Figure 39.17b Conservation efforts • Young whooping cranes can imprint on humans in “crane suits” who then lead crane migrations using ultralight aircraft (b) Pilot and cranes
Figure 39.18 Experiment Spatial learning • digger wasps use landmarksto find nest entrances Nest Pinecone Results http://www.flyfishingdevon.co.uk/salmon/year1/psy128ethology_experiments/wasp_learning_activity.htm Nest No nest
Figure 39.19 Associative Learning Blue Jay learns that Monarchs will cause them to vomit
OPERANT CONDITIONING Involves "training" a behavior using a reward or punishment system. Skinner Box
Mating Systems and Parental Care • Monogamous vs Polygamous? • Is paternal care crucial for survival of offspring? • Certainty of paternity?
Altruism • Natural selection favors behavior that maximizes an individual’s survival and reproduction – selfish • some animals behave in ways that reduce their individual fitness but increase the fitness of others - altruism
Inclusive fitness & Kin selection • natural selection that favors this kind of altruistic behavior by enhancing reproductive success of relatives • Ex: • Belding ground squirrels – alarm call when predators nearby • Naked mole rats – in colonies of 75+, only one queen and 3 kings do all the reproduction
Hamilton’s rule • Natural selection favors altruism when rB C • This inequality is called Hamilton’s rule • Would you risk your life to save your brother/sister?
Figure 39.27 Parent A Parent B Yes! • Assume the average individual has two children. As a result of the sister’s action • The brother can now father two children, so B 2 • The sister has a 25% chance of dying and not being able to have two children, so C 0.25 2 0.5 • The brother and sister share half their genes on average, so r 0.5 • If the sister saves her brother, rB ( 1) C ( 0.5) OR ½ (0.5) probability ½ (0.5) probability Sibling 2 Sibling 1
