BEHAVIOURAL ECOLOGY Introduction to behaviour Fixed action patterns
BEHAVIOURAL ECOLOGY Introduction to behaviour Fixed action patterns Migration Animal signs and communication Mating systems Statistics
ANIMAL BEHAVIOUR Humans have probably studied animal behaviour for as long as we have lived on Earth As hunters, knowledge of animal behaviour is essential to human survival
NIKO TINBERGEN AND BEHAVIOURAL ECOLOGY Extends observations of animal behaviour by studying: 1. How behaviour is controlled 2. How behaviour developed 3. How behaviour evolved 4. How behaviour contributes to survival and reproductive
BEHAVIOURAL ECOLOGY Scientific questions that can be asked about behaviour can be divided into two classes: Those that focus on the immediate stimulus and mechanism for the behaviour – ‘how’ Tinbergen’s questions 1 and 2 Those that explore how the behaviour contributes to survival and reproduction Ultimate causation – ‘why’ Tinbergen’s questions 3 and 4
WHAT IS BEHAVIOUR? Behaviour The nervous system’s response to a stimulus Carried out by the muscular and hormonal system
WHAT IS BEHAVIOUR? Behaviour The nervous system’s response to a stimulus Carried out by the muscular and hormonal system
FIXED ACTION PATTERNS (FAPS) Sequence of unlearned, innate behaviours that is unchangeable Once initiated, it is usually carried to completion FAPs triggered by an external cue known as a
FIXED ACTION PATTERNS (FAPS) Tinbergen observed male stickleback fish responding to a passing red truck In male stickleback fish, the stimulus for attack behaviour is the red underside of an intruder When presented with unrealistic models, the attack behaviour occurs as long as some red is present
MIGRATION Environmental cues can trigger movement in a particular direction Migration
MIGRATION Animals can orient themselves using: 1. The position of the sun and their circadian clock 2. The position of the North Star 3. The Earth’s magnetic field
MIGRATION The Great Monarch Migration
BEHAVIOURAL RHYTHMS Some animal behaviour is affected by the animal’s circadian rhythm, a daily cycle of rest and activity Behaviours such as migration and reproduction are linked to changing seasons, or a circannual rhythm Daylight and darkness are common seasonal cues Some behaviours are linked to lunar cycles, which affect tidal movements
ANIMAL SIGNS AND COMMUNICATION Signal Is a behaviour that causes a change in another animal’s behaviour The transmission and reception of signals Animals communicate using visual, chemical, tactile and auditory signals
ANIMAL SIGNS AND COMMUNICATION Fruit fly courtship 1. Male identifies a female and orients towards her Chemical communication: he smells a females’ pheromones Visual communication: he sees the female and orients his body towards hers
ANIMAL SIGNS AND COMMUNICATION Fruit fly courtship 2. The male alerts the female to his presence Tactile communication: he taps the female with a foreleg Chemical communication: he chemically confirms the female’s identity
ANIMAL SIGNS AND COMMUNICATION Fruit fly courtship 3. The male produces a courtship song Auditory communication: he extends and vibrates his wing If all three steps are successful, the female will allow the male to copulate
ANIMAL SIGNS AND COMMUNICATION Honeybees A bee returning from the field performs a dance to communicate information about the distance and direction of a food source
ANIMAL SIGNS AND COMMUNICATION Many animals communicate through odors (chemical substances) For example, when a minnow or catfish is injured, an alarm substance in the fish’s skin disperses in the water, inducing a fright response among fish in the area
ANIMAL SIGNS AND COMMUNICATION Pheromones can be effective at very low concentrations Nocturnal animals, such as most terrestrial mammals, depend on olfactory and auditory communication Diurnal animals, such as humans and most birds, use visual and auditory communication
MATING SYSTEMS AND SEXUAL DIMORPHISM The mating relationship between males and females varies greatly from species to species Promiscuity No strong pair-bonds or lasting relationships Monogamy One male mates with one female
MATING SYSTEMS AND SEXUAL DIMORPHISM Polygamous An individual of one sex mates with several individuals of the other sex Species with polygamous mating systems are usually sexual dimorphic
MATING SYSTEMS AND PARENTAL CARE Needs of the young are an important factor constraining evolution of mating systems Goal is to maximize reproductive success
MATING SYSTEMS AND PARENTAL CARE Continuous supply of Young soon able to feed and care for
SEXUAL SELECTION AND MATE CHOICE Sexual dimorphism results from sexual selection, a form of natural selection Inter-sexual selection Members of one sex choose mates on the basis of certain traits Intra-sexual selection Competition between members of the same sex for mates
MATE CHOICE BY FEMALES Females can drive sexual selection by choosing males with specific behaviours or features of anatomy Male ornaments often correlate with health and vitality
MALE COMPETITION FOR MATES Which type of sexual selection is male choice? (Intra or inter-sexual selection? ) Such competition may involve agnostic behaviour, an often ritualized contest that determines which competitor gains access to a resource
A (BRIEF) INTRODUCTION TO STATISTICS Why care about statistics? Pared and unpaired ttests
WHY CARE ABOUT STATISTICS? Important to show if your results happened by accident or is a relevant biological phenomenon. Basic ways to describe data include: Mean – Average or Arithmetic mean Median – The value which comes half way when the data are ranked in order Mode – Most common value observed
THE T-TEST Introduction The t-test is perhaps the most important statistical test used in relation to biological variation It enables us to determine the probability that two sample means could have been drawn from the same population of numbers I. e. Are the two samples different from each other?
THE T-TEST
THE T-TEST The t-test boils down to: t= difference between the means standard error of the difference Where: SE = SD sqrt (sample size)
P-VALUES Now that we have our t – value, what does that mean? A p-value helps you determine the significance of your results. All hypothesis tests ultimately use a pvalue to weigh the strength of the evidence you have found in your study
P-VALUES If p > 0. 05, this indicates weak evidence against a null hypothesis you fail to reject the null hypothesis If p < 0. 05, this indicates strong evidence against the null hypothesis you reject the null hypothesis
FOR THE PURPOSES OF THIS COURSE We will be using an online resource to evaluate our t and p values (whew) There are many online (Google search t-test calculator), we will be using http: //graphpad. com/quickcalcs/ttest 1. cfm
RUN THROUGH OF MOCK T -TEST
RUN THROUGH OF MOCK T -TEST We have two groups:
RUN THROUGH OF MOCK T -TEST Step 1: Create Ho and Ha. Ho: There are no differences between the chickens that drank Kool-Aid, and those that did drink not the delicious, refreshing beverage. Ha: There is a difference between chickens that were ‘Kool’ and those that were not ‘Kool’.
RUN THROUGH OF MOCK T -TEST Step 2: Gather Data
RUN THROUGH OF MOCK T -TEST Step 3: Record your data
RUN THROUGH OF MOCK T -TEST Step 3: Graph your data
RUN THROUGH OF MOCK T -TEST Step 4: Analyze your data
RUN THROUGH OF MOCK T -TEST Step 4: Analyze your data A) Choose to enter in your own data
RUN THROUGH OF MOCK T -TEST Step 4: Analyze your data B) Choose an unpaired ttest
RUN THROUGH OF MOCK T -TEST Step 4: Analyze your data C) Enter your data
RUN THROUGH OF MOCK T -TEST Step 4: Analyze your data D) Calculate
RUN THROUGH OF MOCK T -TEST E) Record your Step 4: Analyze your data results
RUN THROUGH OF MOCK T -TEST Step 5: Reject or accept your null hypothesis
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