Unit 4 Ecology I November 9 2015 Lecture 30 Chapter 51 A Behavioral Ecology Behavioral ecology is the study of evolution and ecological basis for animal behavior o Behavioral ecology is the evolution of ecology The way an animal behaves acts on the births and deaths which are the basis of what constitutes a population o Behaviors that include mating response to stimulus etc affect how behavior is controlled how it develops during an animal s life and how it is influenced by genes in the environment o Behavior is a part of the phenotype natural selection can act on it Whether it evolves the same as typical phenotypes depends on differential reproduction and needs to be heritable There are adaptations to learning Such when animals modify their behaviors based on positive reinforcement Example song sparrows modify the songs they sing based on how many mates it attracts o Understanding any behavior requires answering 4 questions o The first two questions ask about the proximate causations the how o The last two questions ask the Why and are the ultimate causes 1 What stimulus elicits the behavior and what physiological mechanisms mediate the response Example Red belly stimulus Male 3 spined sticklebacks have red bellies They attack other males who invade their nesting territories It was observed that every day when a red truck passed by the males would become aggressive An experiment was carried out with different shaped blobs with a red belly and an eye spot along with one realistic shaped fish with an eye spot and no coloring Whenever the males would see a blob with a red lower area and an eye spot they would attack but they would never attack the realistic fish with no coloring This experiment showed that the red color of an intruder s underside is the proximate cause of the attack behavior The territorial response is an example of a fixed action pattern a sequence of unlearned and unchangeable acts directly linked to a simple stimulus The sign stimulus would be the red spot 2 How does the animal s experience during growth and development influence the response Experience and Behavior is based on forms of learning imprinting spatial cognition associative and social Learning is the modification of behavior as a result of specific experiences Example Imprinting Some animals Imprint on a bigger animal Pilot and cranes learned how to migrate in the US When the cranes were becoming extinct they were all taken in and cared for The cranes increased from 47 individuals to 100 individuals This is when they were allowed to go back in the wild In order to do this a pilot wearing a crane suit and flying an ultra light plane acted as a surrogate parent to direct the migration of the whooping cranes It only took one trip to Texas for the cranes to learn and understand the migration behavior Example Associative Learning Is the acquired ability to associate one environment feature such as color with another such as danger Take a na ve blue jay From the time they will eat whatever is in their grasp or whatever is given to them If they happen upon and eat a monarch butterfly who feed on toxic plants then the bird will throw up after realizing it has eaten something harmful From that moment on when the blue jay sees a monarch butterfly or food that is similar to it it will associate that bad experience and will not eat this species Example Social Learning When a Vervet monkey sees a python it gives a distinct snake alarm call to alert the members of its group to stand up and look down Baby Vervet monkeys have to learn the correct use of alarm calls Example Cognitive Portia spider feeds on others After having a few trials they will modify the way they pluck spider webs to get food If they have a positive reinforcement of eating it makes them partake in that specific rhythm of plucking more often 3 How does the behavior aid survival and reproduction The animals now have to balance risks and rewards Example Costs and Benefits Ant lions have two ways in which they can catch food They must weigh out the costs and benefits of the behavior to decide whether to dig a pit and wait for prey to fall in or to hunt actively Example Alone or Group Animals must weigh out whether it is best that they travel alone or among a group Example Food obtaining behaviors foraging eating activities an animal uses to search recognizing and capturing food items Example Some Behaviors are too important to learn If moths detect fear because they can sense the frequency of the bat s echo then it will fold up its wings and begin to plummet fleetly downwards to avoid being eaten Example Genetic Behaviors such as that of the hybrid of the sister love birds One species has a purple red head This species carries its nesting material in its beak In contrast the blue red face species carry its nesting materials on its back When these two species mate they produce a hybrid offspring that will collect materials turn around look over its shoulder as if to put the materials on its back but then it fails to do both behaviors Eventually the hybrid will start to carry its nesting materials in its mouth but only after it takes the time to turn around and look over its back Example Mating Variations in mating system and mode of fertilization affect certainty of paternity which in turn has a significant influence on mating behavior and parental care 4 What is the behaviors evolutionary history Genetic Behaviors genetic analyses and the concept of inclusive fitness provide a basis for studying the evolution of behavior When behavioral variation within a species correlates with variation in environmental conditions it may be evidence f past evolution Lecture 30 Study Questions 1 Many birds live in breeding pairs just two birds in summer and in large flocks groups in winter What is one possible cost and one possible benefit to living in a flock in winter Benefit because temperature is lower in the winter the group will acquire more warmth by huddling together Cost Food is more likely to be scarce in winter therefore more competition for survival between the individuals in the groups 2 In class we covered experiments where Swamp sparrows were raised in three different environments The treatments in the experiment and results are shown below Explain what conclusion about the nature of singing behavior can be drawn from each of these three results Treatment song played to baby birds Result bird s song as adult Conclusion No song Swamp sparrow song
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