How will we approach the study of animal behavior in this course? 1. Text, Lectures, Videos 2. Field Project

Transcription

1 animal behavior

2 How will we approach the study of animal behavior in this course? 1. Text, Lectures, Videos 2. Field Project

3 The text: Dugatkin, 3 rd edition

4 Lectures Mostly we will follow the text. A couple of videos and discussion. Some guest lectures on selected topics, including methodology, elephants, and what is going on at the Oregon Zoo. Lecture notes are up on the website, but sometimes there are last minute changes.

5 Field Project You will go out individually and observe an animal or group of animals. You can choose, and suggestions will be provided, but you must clear your choice with zelick. Several lecture periods will be devoted to methodology for measuring and analyzing behavior and about writing a scientific report. In addition, you have your DVD for reference.

6 Field Project There are three scores for the field project: 1. DVD homework So you know about sampling methods. 2. Proposal You have thought about what do to and how to do it. 3. Report collect data, analyze, summarize, present tables or figures, review scientific literature, discuss results relative to scientific literature.

7 Field Project issues To get a sufficient data sample size, it will be necessary to make multiple measurements over days, and perhaps for a number of hours any one day. So you must budget enough time. As it is Fall, the weather is changing. Behavior you observe one week may be different from a subsequent week with colder temperatures, less leaf cover, etc. 1 st rule of experimental animal behavior: Animals are flakey.

8 Field Project issues, cont d You will have to learn to do simple statistics. The report you write will be in proper scientific format and the data presented with professional style plots. The report will have appropriate scientific references from the primary literature.

9 Exams and Grading There will be 3 each 1-hour exams. Each exam will have 32 questions worth one course point each. The 3 rd hour exam will be at the time of the final (You will have 2 hours for a 1-hour exam). The exams are multiple-choice, scantron graded. They are not cumulative.

10 Exams and Grading The field project is worth 10 pts for the proposal and 40 points for the final project report. The homework assignment of following the sampling methods is worth 4 points = 150 total course points.

11 Organization of the text book Chapter 1 is overview of main concepts Chapters 2 6 cover general biological fundamentals as applied to animal behavior. Chapters 7 17 cover particular topics in ethology.

12 Dugatkin starts off with 3 main approaches to analyzing behavior. These show up as individual chapters later, but are introduced in chapter 1: 1. How natural selection shapes behavior. 2. How learning influences behavior. 3. How learning is aided in groups through cultural transmission of information.

13 So On to the course:

14 In memorium, Alex

15 Animal Behavior is... a scientific discipline, and... what animals do!

16 Arguably, Animal Behavior sits at the very top of the biological hierarchy - an overarching discipline. The behavior of an organism is the culmination of everything that has or is happening in that organism relative to biochemistry, development, genetics, physiology, etc. Not surprisingly, then, the scientific field of animal behavior is broken into a number of subdisciplines

17 Some scientific sub-disciplines associated with animal behavior: behavioral biology ethology neuroethology comparative psychology experimental psychology behavioral ecology behavioral physiology animal communication we will touch on all of these in this course

18 What do animals do? There is a large range from: 1. Simple reflexive responses to an environmental stimulus. 2. Complex patterns of activity in response to accumulated sets of subtle stimuli. to The animals that perform simple or complex behaviors themselves range in complexity from nematodes to primates!

19 Dugatkin s definition of animal behavior Behavior is the internally coordinated responses (actions or inactions) of whole living organisms (individuals or groups) to internal and/or external stimuli, excluding responses more easily understood as developmental changes.

20 The scientific study of animal behavior often relies on model systems. Model systems have advantages and disadvantages: + - large body of data on which to build may ignore most interesting and informative organisms many researchers with different expertise/approaches can work on a problem examples: bird song, fiddler crabs resources may not be available to study less sellable studies example: paddlefish

21 more on model systems: Sometimes model systems get started for the wrong reason - typically convenience. For example, every large university or medical school will have an animal care facility with rats and mice. So there is a ton of data on rodent behavior... The problem with lab rats/mice: they are highly inbred and are raised and live in extremely nonnatural environments.

22 The beginning of the modern study of animal behavior: Nikko Tinbergen and the four questions. A conceptual framework to explain the why of behavior. 1. Causation 2. Function 3. Development 4. Evolutionary History

23 The behavior of sticklebacks (Gasterosteus aculeatus aculeatus). A good model system in animal behavior. Will show up several times in your text. Also very good for illustrating Tinbergen s 4 questions.

24 Summary of some key stickleback behaviors Male stickleback attracts females to a nest he builds. Male courts females, but only large females with a red belly. Large females have more eggs. Red belly indicates eggs are ready to be laid. Male takes care of eggs & fry. Fans eggs to provide more oxygen. Chases away predators. Sucks fry into mouth to protect them. Fry try to evade father when he chases them for protection. Orphan fry are relatively poor at evading predators when they become adults.

25 Male stickleback attracts females to a nest he builds. Male courts females, but only large females with a red belly. Large females have more eggs. Red belly indicates eggs are ready to be laid. 1 Male courting behavior is elicited by a large, redbelly female. The proximate cause (causation) of the male s behavior is large and red belly.

26 1. Causation red belly 2. Function 3. Development 4. Evolutionary History

27 Male courts females, but only large females with a red belly. Large females have more eggs. Red belly indicates eggs are ready to be laid. Male takes care of eggs. Fans eggs to provide more oxygen. Chases away predators. Sucks fry into mouth to protect them. 2 Large females have more eggs, thus the function of courting only large females is passing on more genes. Taking care of eggs and fry ensures better survival of offspring; the function of this behavior is greater reproductive success.

28 1. Causation red belly 2. Function leave more eggs (genes) 3. Development 4. Evolutionary History

29 Fry try to evade father when he chases them for protection. Orphan fry are relatively poor at evading predators when they later become adults. Fry trying to avoid capture by father learn effective evasive techniques. The father is a model for a larger, faster predatory fish. 3 The development, or developmental history of the fry determines the behavior they demonstrate later.

30 1. Causation red belly 2. Function 3. Development learning evasion 4. Evolutionary History

31 Sticklebacks have a wide distribution, from Europe to North America, and live in both lakes and protected ocean areas. Most of the behaviors are similar across the range, but in some ocean populations males have developed additional behaviors. Males may inadvertently attract additional nongravid females while courting a different female. The additional females are potential egg predators. Males from these populations will use nest fanning behavior to lure predatory females away from the real nest.

32 Males from these populations will use nest fanning behavior away from the real nest to lure predatory females away from the real nest. 4 Evolution has taken a different turn the populations have different evolutionary histories and the behaviors are not all the same. Isolated populations can develop different behaviors that are adaptations to the specific environment of each population.

33 1. Causation red belly 2. Function 3. Development 4. Evolutionary History some populations have evolved different behaviors

34 Dugatkin s take on the 4 questions What was the direct stimulus that elicited the behavior? 1, causation 3, development 2, function 4, evolution Reproduction / inclusive fitness What in the history of the individual animal (e.g. learning) promotes a behavior?

35 Tinbergen and other classical early ethologists focused on this. Observation, experimental manipulation directed toward proximate causes. Mostly what is in the text book, and what most biologists do, including current ones.

36 This is what you will do for your project! Observation and reading literature will cause you to form a hypothesis. You then design an experiment to test your hypothesis.

37 Text example: Hamilton s conceptual advance: Realizing that an individual s fitness is not just a function of how well the individual performs, nor how many offspring are produced, but equals the total number of genes left. Helping relatives with whom you share your genes increases your fitness.

38 Total fitness is the sum of direct and indirect fitness. Older daughter helping juvenile daughter increases fitness of herself and the mother.

39 Mathematical models generate theories and hopefully testable hypotheses. For example, if x = 2 and y = 27, then theoretically black bears should prefer trash dumps to blueberries.

40 Of course the cheetah is not doing math, but selection has led to behaviors that follow a good, better or perhaps best solution, and solutions to problems can often be expressed with equations.

41 So what is the cheetah doing? It is visible It is alert It is hunting It is stalking It is doing all of these things. So how do we describe the behavior?

42 BEFORE doing observations the researcher: 1. Comes up with a question to ask. 2. Creates an ETHOGRAM. 3. Determines a sampling methodology.

43 To come up with a reasonable question you must learn about your animal! Soon we will have a lecture on library research. The question must be able to be addressed from a practical perspective.

44 The ethogram has predefined categories of behaviors. The categories must be appropriate for the animal and circumstance of observation. consider whether states or events are important. be mutually exclusive.

45 An experimental ethogram is a list of wellspecified, discrete behaviors that an observed animal may exhibit. In a perfect world, an experimental ethogram would contain every possible behavior that an animal could perform, but this is never really an option. You must, then, come up with as complete a list as possible, often using broad categories that may include multiple behaviors (as long as they remain discrete).

46 Example ethogram: 46

47 Example ethogram analysis 47

48 BEFORE doing observations the researcher: 1. Comes up with a question to ask. 2. Creates an ETHOGRAM. 3. Determines a sampling methodology.

49 Sampling Methodology There isn t one complete answer. The best that we can do is standardize the way that we make observations, and use the proper statistical procedures for a given experiment. 49

50 Sampling Methods Video Best method takes into consideration States vs Events Individuals or Groups, and size of group How you can most accurately observe behavior What question you are asking? For example, is it more important to know how often a behavior occurs or the duration of a behavior?

51 Homework: Sampling Methods Video 1. Ad Libitum sampling: Use to construct ethogram. Subjective/descriptive, nonquantitative. The researcher records the behaviors of individuals or groups s/he encounters, with little or no reference to specific, well-defined methods. This is a good method for initial observations and question-formation for later research, but limited in the quantity and quality of data produced.

52 Homework: Sampling Methods Video 2. Continuous sampling: Comprehensive, but labor-intensive. a) All-occurrences: Typically tally, good for events, not so good for states. b) Focal-animal: May, however, treat group as sampling unit if too many interactions.

53 Homework: Sampling Methods Video All-Occurrences Sampling The researcher selects one or a few specific behavioral events and records every occurrence of that (those) behavior(s) within the animal group (every occurrence of grooming, chasing, etc.). This technique is especially useful in determining the rate, frequency, or synchrony of occurrence of specific behaviors. 53

54 Homework: Sampling Methods Video Focal Animal Sampling The researcher selects one individual to be the primary focus of observation. The researcher records either all behaviors of that individual, or all occurrences of specific behaviors of interest that the focal animal exhibits, during a set period of time.

55 Focal Animal Sampling cont d Individuals may be chosen randomly from all members of the population, or may be chosen with some specific criteria in mind (by age, sex, or reproductive status). There must be some way to keep track of individuals for this method to succeed. This technique is useful for providing data on specific behaviors and is more reproducible than adlibitum sampling.

56 Homework: Sampling Methods Video 3. Non-continuous: More efficient than alloccurrences. a) Scan-sampling individual: best for states. Gives estimates of time spent doing a behavior. b) Scan-sampling group: can be tricky! 4. One-zero sampling: states or events, but bias for rare or common behaviors. Most efficient, but least accurate.

57 More on Scan Sampling The researcher records the instantaneous activity or behavioral state of all animals in the group at predetermined time intervals (e.g., once per minute). It is impossible to record the behavior of all individuals instantaneously, but the researcher attempts to record in as short a time period as possible. Video of the group makes this much easier..

58 More on Scan Sampling The behaviors should be well defined so that scanning is made easier. This method is useful for understanding the frequency with which all animals in the group display certain behaviors or behavioral states. Frequency means, for example, 20 aggressive snarls per hour. In one hour of doing scans, 20 times you wrote down snarl, which is a category on your ethogram.

59 One-zero sampling is quick and easy, but not recommended in most cases. The information you get is limited. Usually used for States. Example: A colonial animal (say a Prairie Dog) is on alert as a sentry. In a 5 minute interval (predetermined interval) you write 1 if sentry or 0 if not.

60 Suppose for 15 minutes you have continuous sentry, so three 1 s are entered. sample interval score In another observation period the animal acts as a sentry for one minute, then not, then starts again, then not. In the next two 5-minute sample intervals there is no sentry.

61 In another observation episode the animal acts as a sentry for one minute, then not, then starts again, then not. But all in the 1 st sample interval In the next two 5-minute sample intervals there is no sentry. sample interval score

62 Even though sentry occurred twice in the first 5- minute sample interval, for one-zero you can only enter 1. So in 15 minutes you have a 3 in the first example and a 1 in the second. What is the frequency of sentry? One-zero does not give you the answer.

63 Steps for project 1. Think about what you want to do, what animal, what question. 2. Do DVD homework to learn about methodologies. 3. Do library research on animal and type of behavior. (Pay attention to library methods lecture) 4. Write 1-page summary of project (Due beginning of week 3) 5. Start data collection. 6. Make report: Reduce, analyze and write up data. Compare your results with those from scientific literature.