1. Chapter 51
Behavioural Ecology

2. Studying behaviour Humans have probably studied animal behaviour
for as long as we have lived on Earth
As hunters
knowledge of animal behaviour was essential to human survival

3. The modern scientific discipline of behavioural ecology
extends observations of animal behaviour by studying how such behaviour is controlled and how it develops, evolves, and contributes to survival and reproductive success

4. Concept 51.1: behavioural ecologists distinguish between proximate and ultimate causes of behaviour
The 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
those that explore how the behaviour contributes to survival and reproduction

5. What Is behaviour? Behaviour is what an animal does and how it does it
includes muscular and nonmuscular activity
Figure 51.2
Dorsal fin
Anal fin

6. Learning
is also considered a behavioural process

7. Proximate and Ultimate Questions
Proximate, or “how,” questions about behaviour
focus on the environmental stimuli that trigger a behaviour
focus on the genetic, physiological, and anatomical mechanisms underlying a behavioural act
e.g. How does day length influence breeding in birds?
increased day (environmental stimuli) length triggers hormone production associated with reproduction like singing & nest building

8. Ultimate, or “why,” questions about behaviour
address the evolutionary significance of a behaviour
Why did natural selection favour this type of behaviour?
Proximate & ultimate causation are linked
e.g. many animals breed during spring & summer because of warmth of seasons
abundant food supply may increase chances of offspring surviving

9. Ethology Ethology is the scientific study of animal behaviour
particularly in natural environments
Karl von Frisch, Konrad Lorenz, & Niko Tinbergen
What are the questions that must be answered to understand any behaviour?
What is the mechanistic basis of the behaviour, including chemical, anatomical, physiological mechanisms?
How does development of an animal influence behaviour?
What is the evolutionary history of the behaviour?
How does behaviour contribute to survival & reproduction (fitness)?

10. Behaviours typically studied by ethologists Fixed Action Patterns
A fixed action pattern (FAP)
is a sequence of unlearned, innate behaviours that is unchangeable
once initiated, is usually carried to completion

11. A FAP is triggered by an external sensory stimulus
known as a sign stimulus

12. In male stickleback fish, the stimulus for attack behaviour
is the red underside of an intruder
Figure 51.3a
(a) A male three-spined stickleback fish shows its red underside.

13. When presented with unrealistic models
as long as some red is present, the attack behaviour occurs
Figure 51.3b
(b) The realistic model at the top, without a red underside, produces no aggressive response in a male three-spined stickleback fish. The other models, with red undersides, produce strong responses.

14. Proximate and ultimate causes for the FAP attack behaviour in male stickleback fish
Figure 51.4
ULTIMATE CAUSE: By chasing away other male sticklebacks, a male decreases the chance that eggs laid in his nesting territory will be fertilized by another male.
Behaviour: A male stickleback fish attacks other male sticklebacks that invade its nesting territory.
PROXIMATE CAUSE: The red belly of the intruding male acts as a sign stimulus
that releases aggression in a male stickleback.

15. Imprinting Imprinting is a type of behaviour
that includes both learning and innate components and is generally irreversible

16. An example of imprinting is young geese
Imprinting is distinguished from other types of learning by a sensitive period
a limited phase in an animal’s development that is the only time when certain behaviours can be learned
An example of imprinting is young geese
following their mother

17. Konrad Lorenz showed that
when baby geese spent the first few hours of their life with him, they imprinted on him as their parent

18. There are proximate and ultimate causes for this type of behaviour
Figure 51.5
Behaviour: Young geese follow and imprint on their mother.
PROXIMATE CAUSE: During an early, critical developmental stage, the young geese observe their mother moving away from them and calling.
ULTIMATE CAUSE: On average, geese that follow and imprint on their mother receive more care and learn necessary skills, and thus have a greater chance of surviving than those that do not follow their mother.

19. Conservation biologists have taken advantage of imprinting
in programs to save the whooping crane from extinction
Figure 51.6

20. Concept 51.2: Many behaviours have a strong genetic component
Biologists study the ways both genes and the environment
influence the development of behavioural phenotypes
nature-versus-nurture issue is not about whether genes or environment influence behaviour
how are both involved?
Behaviour that is developmentally fixed
is called innate behaviour and is under strong genetic influence

21. Directed Movements Many animal movements These types of movements
are under substantial genetic influence
These types of movements
are called directed movements

22. Kinesis
A kinesis
is a simple change in activity or turning rate in response to a stimulus

23. Pill bugs
become more active in dry areas and less active in humid areas
Figure 51.7a
Dry open area
Moist site under leaf
(a) Kinesis increases the chance that a sow bug will encounter and stay in a moist environment.

24. Taxis
A taxis
is a more or less automatic, oriented movement toward or away from a stimulus

25. Many stream fish exhibit positive rheotaxis
where they automatically swim in an upstream direction
Direction
of river
current
(b) Positive rheotaxis keeps trout facing into the current, the direction from which most food comes.
Figure 51.7b

26. Migration Many features of migratory behaviour in birds
have been found to be genetically programmed
Figure 51.8

27. e.g. blackcap = warbler – range from Cape Verde Islands to N. Europe
behaviour = N. Europe populations migrate at night
-CVI populations do not migrate
-NE pop. exhibit migratory restlessness when held in captivity
experiment = cross German with CVI blackcaps
result = 40% of offspring show migratory restlessness
conclusion = must be under genetic control

28. Animal Signals and Communication
In behavioural ecology
a signal is a behaviour that causes a change in another animal’s behaviour
Communication
is the reception of and response to signals

29. Animals communicate using
visual, auditory, chemical, tactile, and electrical signals
The type of signal used to transmit information
is closely related to an animal’s lifestyle and environment

30. Chemical Communication
Many animals that communicate through odors
emit chemical substances called pheromones
common among mammals & insects
often relate to reproductive behaviour
context is important
e.g. honey bee hive
inside hive pheromones maintain social order
outside triggers mating with queen

31. 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
Figure 51.9a, b
(a) Minnows are widely dispersed in an aquarium before an alarm substance is introduced.
(b) Within seconds of the alarm substance being introduced, minnows aggregate near the bottom of the aquarium and reduce their movement.

32. Auditory Communication
Experiments with various insects
have shown that courtship songs are under genetic control
Charles Henry, Lucía Martínez, and ent Holsinger crossed males and females of Chrysoperla plorabunda and Chrysoperla johnsoni, two morphologically identical species of lacewings that sing different courtship songs.
EXPERIMENT
SONOGRAMS Chrysoperla plorabunda parent
Vibration volleys
Standard repeating unit
Chrysoperla johnsoni parent Volley period
crossed with
The researchers recorded and compared the songs of the male and female parents with those of the hybrid offspring that had been raised in isolation from other lacewings.
Volley period

33. The F1 hybrid offspring sing a song in which the length of the standard repeating unit is similar to that sung by the Chrysoperla plorabunda parent, but the volley period, that is, the interval between vibration volleys, is more similar to that of the Chrysoperla johnsoni parent.
RESULTS
The results of this experiment indicate that the songs sung by Chrysoperla plorabunda and Chrysoperla johnsoni are under genetic control.
CONCLUSION
Standard repeating unit
Volley period
F1 hybrids, typical phenotype

34. Genetic Influences on Mating and Parental behaviour
A variety of mammalian behaviours
are under relatively strong genetic control

35. Research has revealed the genetic and neural basis
for the mating and parental behaviour of male prairie voles
arginine-vasopressin (AVP)
Figure 51.11

36. Concept 51.3: Environment, interacting with an animal’s genetic makeup, influences the development of behaviours
Research has revealed
that environmental conditions modify many of the same behaviours

37. Dietary Influence on Mate Choice behaviour
One example of environmental influence on behaviour
is the role of diet in mate selection by Drosophila mojavensis

38. Proportion of matings by Sonoran females
Laboratory experiments have demonstrated
that the type of food eaten during larval development influences later mate choice in females
Figure 51.12
William Etges raised a D. mojavensis population from Baja California and a D. mojavensis population from Sonora on three different culture media: artificial medium, agria cactus (the Baja host plant), and organ pipe cactus (the Sonoran host plant). From each culture medium, Etges collected 15 male and female Baja D. mojavensis pairs and 15 Sonoran pairs and observed the numbers of matings between males and females from the two populations.
EXPERIMENT
When D. mojavensis had been raised on artificial medium, females from the Sonoran population showed a strong preference for Sonoran males (a). When D. mojavensis had been raised on cactus medium, the Sonoran females mated with Baja and Sonoran males in approximately equal frequency (b).
RESULTS
The difference in mate selection shown by females that developed on different diets indicates that mate choice by females of Sonoran populations of D. mojavensis is strongly influenced by the dietary environment in which larvae develop.
CONCLUSION
100 75 50 25
Artificial
Organ pipe cactus
Agria cactus
Culture medium
With Baja males
With Sonoran males
(b)
Proportion of matings by Sonoran females
(a)

39. Therese Markow and Eric Toolson proposed
that the physiological basis for the observed mate preferences was differences in hydrocarbons in the exoskeletons of the flies
Figure 51.13

40. Social Environment and Aggressive behaviour
Cross-fostering studies in California mice and white-footed mice
have uncovered an influence of social environment on the aggressive and parental behaviours of these mice
California mice – monogamous, highly aggressive, extensive parental care
white-footed mice – not monogamous, little parental care

41. Influence of cross-fostering on male mice
Table 51.1

42. Learning Learning is the modification of behaviour Learned behaviours
based on specific experiences
Learned behaviours
range from very simple to very complex

43. Habituation Habituation
is a loss of responsiveness to stimuli that convey little or no information

44. Spatial Learning Spatial learning is the modification of behaviour
based on experience with the spatial structure of the environment

45. In a classic experiment, Niko Tinbergen
showed how digger wasps use landmarks to find the entrances to their nests
Figure 51.14
CONCLUSION
A female digger wasp excavates and cares for four or five separate underground nests, flying to each nest daily with food for the single larva in the nest. To test his hypothesis that the wasp uses visual landmarks to locate the nests, Niko Tinbergen marked one nest with a ring of pinecones.
EXPERIMENT
Nest
When the wasp returned, she flew to the center of the pinecone circle instead of to the nearby nest. Repeating the experiment with many wasps, Tinbergen obtained the same results.
RESULTS
The experiment supported the hypothesis that digger wasps use landmarks to keep track of their nests.
No Nest
After the mother visited the nest and flew away, Tinbergen moved the pinecones a few feet to one side of the nest.

46. Cognitive Maps A cognitive map
is an internal representation of the spatial relationships between objects in an animal’s surroundings
how do you distinguish between animal using landmarks & one using cognitive map?
e.g. corvids – store food in caches from which bird can retrieve food later
pinyon jays & Clark’s nutcrackers store nuts in as many as thousands of caches
can relocate caches
can also keep track of food quality

47. Associative Learning In associative learning
animals associate one feature of their environment with another

48. Classical conditioning is a type of associative learning
in which an arbitrary stimulus is associated with a reward or punishment
Before stimulus
Influx of water alone
Influx of alarm substances
Influx of pike odor
Day 1
Day 3
Control group
Experimental group
Experimental group
Relative activity level
Figure 51.15

49. Operant conditioning is another type of associative learning
in which an animal learns to associate one of its behaviours with a reward or punishment
Figure 51.16

50. Cognition and Problem Solving
Cognition is the ability of an animal’s nervous system
to perceive, store, process, and use information gathered by sensory receptors
cognitive ethology – examines connection between animal’s nervous system & it’s behaviour
how animal’s brain represents objects in environment
many animals (including insects) capable of distinguishing “same” & “different” objects

51. animals have substantial ability to process information
problem solving behaviour highly developed in primates & dolphins, some birds especially crows, ravens, jays

52. Problem solving can be learned
by observing the behaviour of other animals
Figure 51.17

53. Genetic and Environmental Interaction in Learning
Genetics and environment can interact
to influence the learning process
Some songbirds have sensitive period for developing their songs
individuals reared in silence performed abnormal songs, but if recordings of proper songs were played early in life of bird, normal songs developed

54. Canaries exhibit open-ended learning where they add new syllables to their song as they get older