ANIMAL BEHAVIOR

43 _____________________________________________________________________________________________ Animal Behavior Chapter Outline Alarming bee behavior Behavioral Genetics Genetic Variation within a Species Genetic Variation among Species Human Behavior Genetics Instinct and Learning Instinctive Behavior Time-Sensitive Learning Conditioned Responses Other Types of Learned Behavior ENVIRONMENTAL EFFECTS ON BEHAVIORAL TRAITS Behavioral Plasticity Epigenetic Effects Movements and Navigation Taxis and Kinesis Migration Communication Signals Evolution of Animal Communication Types of Signals Eavesdroppers and Counterfeiters Mates, Offspring, and Reproductive Success Mating Systems Parental Care Living in Groups Defense against Predators Improved Feeding Opportunities Dominance Hierarchies Regarding the Costs Why Sacrifice Yourself? Social Insects Social Mole-Rats Evolution of Altruism alarming bee behavior (revisited) Summary data alalysis activities self-quiz critical thinking questions Objectives 1. Understand how scientists have proven that some behavioral traits are genetic. 2. Learn about the concepts of instinctive behavior, learned behavior, imprinting, and conditioning. 3. Understand how behavior is influenced by environment, as in behavioral plasticity and epigenetic behavior. 4. Know the instinctual responses to stimuli, such as kinesis and taxis. 5. Be able to describe how adaptive behaviors develop. 6. Study the various forms of communication between individuals of a species. 7. Know the basis for sexual selection and parental care in various animal populations. 8. Compare the pros and cons of animals living in groups. 9. Understand why some animals exhibit subservient behavior for the wellbeing of the population. Key Terms stimulus instinctive behavior fixed action pattern learned behavior imprinting classical conditioning operant conditioning habituation observational learning communication signals behavioral plasticity pheromone kinesis migration taxis tactile display lek territory dominant hierarchy sexual selection selfish herd altruistic behavior eusocial behavior theory of inclusive fitness Lecture Outline 43.1 Alarming Bee Behavior A. Africanized “killer bees” have arrived in the United States. 1. This type of bee resulted from African bees that mated with European varieties. 2. These bees are no more venomous than regular honeybees, but they are much more aggressive. a. There have been rare fatalities, particularly in those that are allergic to bee stings. 3. They have a heightened sensitivity to the alarm pheromones released from a fellow bee. a. When threatened, a bee releases a warning pheromone that brings other bees to the area. 43.2 Behavioral Genetics A. Genetic Variation within a Species 1. Animals react to different stimuli in a way that is genetic in nature. a. Experiments performed by mating two different types of garter snakes with different food preferences helped to prove this. b. Fruit flies show an identified genetic marker to indicate whether they are “rovers” or “sitters” Rovers move around as they feed and sitters remain in one spot. These two distinct groups of flies show different amounts of an enzyme responsible for foraging. B. Genetic Variation among Species 1. Hormone production, which is genetic, influences animal behavior. a. Studies were performed on voles relating to oxytocin levels and the animal’s preference for monogamy. b. Additional studies indicated a link between arginine vasopressin hormone and promiscuity in voles. C. Human Behavior Genetics 1. It is thought that most human traits are based on several genes and environmental influences. 2. Experiments are being performed to see if autistic children either produce less oxytocin or have fewer oxytocin receptors. a. Trials are underway to determine if oxytocin could be a treatment for autism. 43.3 Instinct and Learning A. Instinctive Behavior 1. Animals are born with some instinctive behaviors. a. An example is the procedure by which cuckoo birds discard other eggs in the foster parent’s nest. 2. The cuckoo birds’ actions are considered an example of a fixed action pattern. b. A fixed action plan means that once the action is initiated, the rest of the actions automatically follow without the need for additional cues. B. Time-Sensitive Learning 1. Imprinting is when a particular behavior is learned during a certain time period. a. The standard example of imprinting shows baby geese following any maternal figure when exposed at an early age. b. There appears to be a window of opportunity for birds to learn a species-specific song. C. Conditioned Responses 1. Animals can learn throughout life based on a positive and negative reward system. a. Classical conditioning can be defined as an animal connecting two stimuli together when presented at the same time. The typical example of classical conditioning is Pavlov’s dogs salivating due to the anticipation of food. 2. Operant conditioning occurs when an animal changes his behavior based on a positive-negative reward system. D. Other Types of Learned Behavior 1. Habituation is when an animal learns a behavior even though it has not been exposed to a reward system. a. Lobsters learn to recognize other lobsters they have battled. 2. Observational learning occurs when an animal learns to mimic an activity performed by another animal. 43.4 Environmental Effects on Behavioral Traits A. Behavioral Plasticity 1. Behavioral plasticity is when behavioral traits are changed by environmental factors. a. An example occurs when caterpillars infested with parasites consume harmful alkaloids to rid themselves of the parasites. b. Under normal circumstances, the caterpillars would shun the harmful alkaloids. 2. Male cichlid fish can be dominant or subordinate depending on the social environment. B. Epigenetic Effects 1. Heritable changes occur in behavior without changing the DNA sequence. a. A female rat who doesn’t get much grooming from her mother does not groom her offspring. 1) Researchers have observed demethylation of the DNA of those rats not receiving the tactile stimulation early in life. 2) This demethylation is passed on to their offspring. 43.5 Movements and Navigation A. Taxis and Kinesis 1. An innate directional response is called taxis. a. Planarians automatically move away from light and toward gravity. 2. Kinesis is defined by an animal speeding up or slowing down its rate with no regard for direction. a. Planaria move more in light than darkness. B. Migration 1. Migration is when an animal makes a determined effort to arrive at a new habitat. a. Animals, like birds, often winter in a warmer environment and then return to the original location. b. Other animals return to its hatching site to breed and die. 2. Some animals use an innate compass that enables them to detect the variations in the Earth’s magnetic field. 3. Some animals use the location of the moon and stars to find their direction. 43.6 Communication Signals A. Evolution of Animal Communication 1. Animals use various means of communication to relay information to another of their species. a. The communication persists only if it is of benefit to both parties involved. B. Types of Signals 1. Pheromones are chemical signals and often active in mate selection. 2. Animals emit auditory signals to signal prospective mates or to warn others of danger. 3. Visual displays are often used to attract a mate. 4. A tactile display involves one individual transmitting a message by touching another. a. The bees’ waggle dance relates the distance and location of a food source to other bees. C. Eavesdroppers and Counterfeiters 1. Some predators listen to communication between organisms to locate prey. a. Bats use this method to located frogs. 2. Other animals mimic the signals of other species to attract a meal. b. Other predator insects imitate the flashes of fireflies to lure them closer. 43.7 Mates, Offspring, and Reproductive Success A. Mating Systems 1. Individuals often compete in various ways for mating privileges known as sexual selection. a. Male hangingflies must bring large gifts of food to win over females. b. Females observe the male fiddler crabs waving their large claw. c. Male birds put on a colorful display to impress females. d. A lek is an area where birds exhibit their mating displays. e. A territory refers to an area where males fight off others for domination. B. Parental Care 1. Many species involve parental care duties. a. Many birds and some mammals are cared for by both parents. b. Young reptiles, with the exception of crocodiles, do not require parental care. c. Most mammals are cared for by the mother animal. 432.8 Living in Groups A. Defense against predators. 1. Often groups of animals deter predators. a. Examples include sawfish caterpillars and other animals such as prairie dogs, who give a warning call. b. A selfish herd is when the members of a group of animals tend to hide behind one another. B. Improved Feeding Opportunities 1. Animals in groups may have advantageous feeding opportunities. a. Group hunting may not actually provide more food, but may be better for protection. b. Animals in groups may learn behaviors from each other, like the utilization of tools in primates. C. Dominance Hierarchies 1. Some animals establish hierarchies in their group structure. a. Wolves develop packs and only the dominant members can mate. D. Regarding the Costs 1. In some circumstances, living in groups is disadvantageous. a. Groups may attract predators and spread diseases more readily. b. Animals in a group must compete for food and space. 43.9 Why Sacrifice Yourself? A. Social Insects 1. Eusocial animals have developed a system where there are only a few breeding individuals. a. Insects that have this system are ants, termites, and bees. b. Other insects have auxiliary functions to support the queen. B. Social Mole-Rats 1. African mole-rats are the only mammals with this organizational structure. C. Evolution of Altruism 1. Workers in a eusocial society show altruistic behavior, which means working toward the good of the group. a. The theory of inclusive fitness explains that this behavior helps promote reproductive success of relatives. b. Since relatives share the same gene pool, this behavior helps promote reproductive success of their own genes. 43.10 Alarming Bee Behavior (Revisited) Honeybee females sting, but it sacrifices their life. While the stinger is in the skin, additional venom can enter the skin. Remove the stinger to prevent more venom from pumping into the skin. The stinging sensation results from the injection of mellitin. Mellatin results in the flow of ions that translate into the sensation of pain in the brain. Suggestions for Presenting the Material • It might be interesting to start out your discussion of animal behaviors by talking about particular animal actions and see if the students can make a guess as to how they are derived. Start out with some easy ones; for example, a monkey learns which lever to press to get a reward. As your discussion continues, get into some more confusing behaviors, such as why a dog circles around before it sits. This will enable the students to see that it is not always so easy to determine the cause or method by which a behavior originates. This may spark their interests in learning more about animal behaviors. • If possible, show some slides illustrating animal behavior. Many of our students are primarily visual learners and they may understand the actions better by actually viewing them. • Be sure to stress the specific definitions of classical and operant conditioning so that the students are clear on the differences. • Utilize a “Jeopardy” of “Who Wants To Be a Millionaire” format to learn key terms. Templates can be found at the following website: _http://teach.fcps.net/trt2/links/powerpointgames.htm_ There may be students in the class that have taken their dog to obedience class. Have them describe the process and what type of learning it utilized. Classroom and Laboratory Enrichment • For those students in the class with some animal experiences, have them name behavior that seems based on instinct. Does there seem to be any advantage to this behavior at one time? Is there any advantage to this behavior now? If not, why does the behavior persist? • When training animals to learn a behavior, what method works best? If you provide positive reinforcement, how do you determine the most effective reward? • Humans record habit memory in an area of the brain known as the corpus striatum. Is this area of the brain present in other animals that exhibit the habituation type of learned behavior? • Can you think of other specific courtship displays in other animals? In some species of lizards, for example, the female releases hormones that prepare her for reproduction only after she is stimulated by the male’s visual display. • Has anyone viewed the television program “Meerkat Manor”? Have the meerkats on the program displayed any of the behaviors discussed in the chapter? • The text shows that groups of animals, such as lions, are not more effective hunters in a group. Why do you suppose they often continue this behavior in spite of its lack of success? • Place an ant farm in the classroom. They are inexpensive and fairly easy to maintain. Observe the functions of the different groups of ants in their eusocial community. Classroom Discussion Ideas • Discuss the role of pheromones in insect management. Traps can be devised containing female pheromones and a sticky surface. When the males enter, expecting to find females of their species, they are trapped. Some farmers also use pheromones to simply encourage damaging insects away from their crops by placing pheromones in a distant location. Why are pheromones not used more often by commercial exterminators or regular homeowners? • Could the pheromones of Africanized honeybees be different enough from those of regular bees that they could be used to capture them? • Do you envision Africanized honeybees spreading further into additional states? Why or why not? • Recently there has been a decline in the number of populations of normal honeybees. Do you have any ideas why this may be occurring? • Which traits of the Africanized honeybee make it more adaptive than the European honeybee? • Why would any Africanized honeybees sting so rapidly when they can sting only once? Does this seem like an adaptive behavior? With the advent of global warming, do you envision the Africanized honeybee colonies to spread northward? Should drastic methods be undertaken to destroy Africanized honeybees in the U.S.? Even at the expense of destroying indigenous populations of bees that are important for fertilization? How have other induced species proved detrimental to their new environments? How were these non-native populations addressed? Could this provide valuable information as far as how the Africanized honeybee situation could be handled? Additional Ideas for Classroom Discussion • We have seen that animals respond to different stimuli. Often animals respond to stimuli that we cannot even detect. For example, it is said that a shark can smell a few drops of blood in an area the size of a swimming pool. For each of our special senses (vision, smell, taste, hearing), name an animal whose ability to detect stimuli may be more acute than ours. How is this ability adaptive? • From the studies performed on birds, it seems as though they have a window of opportunity to learn to sing a species-specific song. Do humans have this same time period during which they must learn language? This may be hard to prove or disprove since there are few examples of humans developing without early exposure to language. Do you think this could affect an individual’s ability to learn a second language more easily early in life? • Can you think of other examples of a fixed-action behavior of instinctive behavior like that of the cuckoo and the foster parent? Do humans exhibit any behaviors that seem similar? • Does your household pet exhibit any of the behaviors noted in this chapter? Which of their behaviors appear instinctive? Which ones are learned behaviors? Do they initiate any communication signals to you or other animals? Can you easily interpret what some of these signals mean? • From the bright coloration of many male birds’ feathers, we can assume that birds can discern colors and that they are used as a visual display for prospective mates. Research some additional specific courting behaviors in different species of birds. • The chapter mentions the fact that chimpanzees use sticks to extract termites from their mound. Can you think of other similar primate behaviors utilizing primitive tools? • Discuss the different levels of prenatal care given to various animal species. • Often the alpha male of a wolf pack is the largest individual. Can you see a genetic advantage to passing those genes along? Do humans keep some of these same characteristics in mind when they select a mate? • Investigate the study involving the natives in Papua New Guinea and infanticide. Can you find other cultures with a similar practice? Can you see any increase in this type of behavior in ghetto areas where the daily stress is high? Oxytocin is sometimes called the “cuddle hormone.” Do you think this nickname is accurate, considering that it may involve the monogamous practices of voles? Mention examples of migration that occurs over long distances. The gray whale is an excellent example, since they travel approximately 5,000–6,800 miles! How do insects make sounds by rubbing their legs together? What is the purpose of these sounds? How Would You Vote? Classroom Discussion Idea • Monitor the voting for the online question. Obviously there is something in the genetics of the Africanized bees that gives them a heightened response to the alarm hormone. • These bees would be especially dangerous for the many individuals who react adversely to insect bites. These highly allergic individuals may experience dangerous anaphylactic shock as a result of a single bee sting and may require an emergency-department visit. • If genetic engineering were successfully performed on the Africanized bees, they might be able to convert their aggressive nature to that of normal honeybees. • The question really involves how you want to spend your genetic-research money. I think most individuals would rank eradication of diseases like cancer and AIDS as a much more important use of their research funds. Term Paper Topics, Library Activities, and Special Projects • In the studies examining behavioral genetics, fruit flies were utilized to isolate a particular gene that determines if flies are rovers or sitters. Why is Drosophila used so often for genetic studies? When did researchers begin using fruit flies in the study of genetics? What features do they possess that make them well adapted to this kind of study? • Research information regarding the functions of oxytocin and antidiuretic hormone in humans. Both of these hormones are made in the hypothalamus and stored in the posterior lobe of the pituitary gland. Since the oxytocin level appears to be associated with autism-like disorders, have any studies compared the hypothalamus from normal individuals with that of autistic patients? • Perform additional research into Lorenz’s studies on imprinting in geese. Can you find any studies with other species where imprinting occurs? • Look into Koko’s World, a project where humans taught sign language to gorillas. There is evidence as part of this study that other gorillas began imitating Koko’s use of sign language appropriately. What type of learned behavior does this represent? • How did researchers go about translating the motions of the honeybee waggle dance? Can humans actually locate the source of the food by interpretation of the dance alone? • Human pheromones are for sale on the Internet. Can you find any studies that indicate their role in human mate selection? • Read Ivan Pavlov’s original paper on classical conditioning from the 1890s. He originally set out to study the digestive enzymes of dogs from an anatomical standpoint. His research changed focus when he noticed a “psychic secretion” in the dogs’ mouths. Do you think you could have derived his theory of classical conditioning if presented with the same laboratory results? Read more about Stevan Arnold’s research involving the feeding behavior of garter snakes. Do you think this same genetic alteration that affects feeding preferences exists in other animals? Other similar studies involve the feeding practices of rats—what did they conclude? Can you locate any research that attempts to connect oxytocin levels or number of oxytocin receptors and autism? Ludwig Huber and Bernhard Voelkl performed experiments in which marmosets learned certain behaviors by observing the actions of other marmosets. Are there any similar studies utilizing other species? This chapter mentions the experiment that illustrated that rats that received little grooming behavior as infants often do not provide this kind of behavior to their offspring. Scientists have proven that their DNA actually changed and this change was passed on to their offspring. Do humans that receive little nurturing during infancy often fail to provide this practice to their offspring? Do you think epigenetic effects of this type occur in humans or is it strictly learned behavior? Devise an experiment that would test the internal compass of birds. An interesting phenomenon occurs with sea turtles called arribada. Masses of sea turtles migrate to the same beach to lay eggs. How far do they travel? How do you think they locate the same location each year? Possible Responses to Critical Thinking Questions 1. The act of moths flying toward the light seems to be an instinctual behavior. These types of actions can remain in a species even though they no longer serve a purpose, or in this case are actually disadvantageous. I would equate this behavior to that of a dog who spins around in several circles before lying down. Both of these behaviors are based on instinct and persist long beyond their usefulness. 2. Since the non-breeding Damaraland mole-rats are not related to those that breed, the purpose of their behavior cannot be genetic in nature. The researchers feel that the actions of the non-breeding mole-rats are ecological, meaning that it enables the mole-rats to survive more successfully long term in their current environment. Possible Responses to Data Analysis Exercise Questions African honeybees appear to be quite dominant in their newly adopted environment. This study traces their entry into the United States. The Africanized bees first became established in Texas. It appears as though Florida, Arkansas, and Louisiana first developed colonies of Africanized bees in 2005. It is likely that Africanized bees were transported to Florida via humans, because there are no established colonies in Mississippi or Alabama, which are located between Florida and other infested states. Animal Behavior 406 425 Animal Behavior 432 Chapter Forty-Three Animal Behavior 433 432 Chapter Forty-Three Animal Behavior 433 432 Chapter Forty-Three Animal Behavior 433 432 Chapter Forty-Three Animal Behavior 433 432 Chapter Forty-Three Animal Behavior 433