Behavioural Biology
Principles of Animal Behaviour
1. Definitions of behaviour
a. A directed response of an organism to the environment (or more specific
towards an environmental stimulus)
b. Normally, behaviour is expressed by a physical movement (e.g. cheetah
chasing gazelle)
c. Behaviour occurs in different functional contexts or behavioural domains (e.g.
to obtain food)
d. Elaborate and extensive behaviours are limited to organisms of the animal
kingdom, but bacteria, fungi and plants are also capable of ‘’behaviour’’ (e.g.
venus flytrap closing to catch flies)
2. Why is animal behaviour important?
a. Survival as our own, using animals as a food resource (hunting, gathering)
i. Behaviour importance
1. Which animals to hunt, when, where, how?
2. Phase of the day (e.g. day, dusk)
3. Season of the year (e.g. during migration periods)
4. Habitat preference (e.g. food preference)
b. Use of animals as a work force to social support
i. Support for defense and hunting (dogs, birds)
ii. Riding and plowing (horses and cattle)
iii. Production of organic matter from clothes (wool, silk) to food (milk,
meat)
iv. Social and therapeutic use (e.g. for children)
c. Environmental protection
i. Protection of species from extinction to counteract decline of
biodiversity due to human impact
ii. Regulation of species numbers due to lack of natural predators or
depleted resources to maintain/restore ecological balance (e.g.
oostvaardersplassen)
d. Animal welfare (ethical aspects)
i. Prevention of health problems in captive animals
ii. Avoidance of excessive stress in animal farms for meat production
(e.g. space demands, aggression)
iii. Avoidance of unacceptable suffering in animal research
e. Scientific/biomedical research
i. Understanding of ecological aspects of behaviour
ii. Understanding animal behaviour to improve understandings of
mechanisms underlying human behaviour
iii. To improve our own disease treatments and disorders, this is a basic
requirement to increase life expectation and improve quality of life
,3. The importance of behavioural neuroscience
a. Understand the neuronal and molecular basis underlying normal behaviour
b. Develop an improved mechanistic understanding of pathological behaviour
4. Tinbergen’s four types of ethological questions
, a. Divided in proximate, HOW and ultimate, WHY questions
In house finches, plumage difference:
Proximate, How – what causes the males and females to differ in plumage condition?
Carotenoid based foods that the males actively search for.
Ultimate , Why – why do females prefer red males? Red colored males are less effected by
bacterial pathogen less affected and recovered faster , disease resistance.
Why do males actively search for carotenoid based foods – because much more likely to find
mate increased reproductive succes
, Hormones and Neurobiology
1. Ultimate (evolutionary/ecology) and proximate (physiology/) perspectives
a. Example for better vision (acuity) in robins
i. Natural selection of individuals with better acuity due to improved
reproductive success (better food resources, better predator
avoidance) = Ultimate explanation based on evolutionary processes =
WHY question
ii. Improved sensory function = Proximate (mechanistic) explanation
based on physiology = HOW question
iii. Improved neural processing (e.g. faster detection and discrimination)
= Proximate (mechanistic) explanation based on physiology = HOW
question
iv. Single mutations resulting in beneficial genetic effects that improve
the function of proteins involved in visual perception = Proximate
(mechanistic) explanation based on physiology = HOW question
b. Example for the red vs. yellow colour of finches
i. What causes such a color variation = Proximate question = HOW
question
1. Food containing carotenoids serve as a red color pigment (e.g.
carrots being used as food for salmon instead of natural foods
like crustaceans)
2. Individual colouring and colouring between populations may
vary due to other foraging strategies
3. Males are often more red than females due to the fact that
males forage for food with carotenoids
ii. Why do males but not females actively search for carotenoid-based
foods = ultimate question = WHY question
1. Because bright coloured individuals have a way higher chance
of mating than a lightened individual because they are
preferred by females
2. Red is preferred by females because red animals are less
susceptible for disease than the yellow one
3. Feather degrading bacteria could be an important factor
influencing the ecology and evolution of birds
4. Females lower the risk of pathogen exposure by selecting red-
coloured males
Principles of Animal Behaviour
1. Definitions of behaviour
a. A directed response of an organism to the environment (or more specific
towards an environmental stimulus)
b. Normally, behaviour is expressed by a physical movement (e.g. cheetah
chasing gazelle)
c. Behaviour occurs in different functional contexts or behavioural domains (e.g.
to obtain food)
d. Elaborate and extensive behaviours are limited to organisms of the animal
kingdom, but bacteria, fungi and plants are also capable of ‘’behaviour’’ (e.g.
venus flytrap closing to catch flies)
2. Why is animal behaviour important?
a. Survival as our own, using animals as a food resource (hunting, gathering)
i. Behaviour importance
1. Which animals to hunt, when, where, how?
2. Phase of the day (e.g. day, dusk)
3. Season of the year (e.g. during migration periods)
4. Habitat preference (e.g. food preference)
b. Use of animals as a work force to social support
i. Support for defense and hunting (dogs, birds)
ii. Riding and plowing (horses and cattle)
iii. Production of organic matter from clothes (wool, silk) to food (milk,
meat)
iv. Social and therapeutic use (e.g. for children)
c. Environmental protection
i. Protection of species from extinction to counteract decline of
biodiversity due to human impact
ii. Regulation of species numbers due to lack of natural predators or
depleted resources to maintain/restore ecological balance (e.g.
oostvaardersplassen)
d. Animal welfare (ethical aspects)
i. Prevention of health problems in captive animals
ii. Avoidance of excessive stress in animal farms for meat production
(e.g. space demands, aggression)
iii. Avoidance of unacceptable suffering in animal research
e. Scientific/biomedical research
i. Understanding of ecological aspects of behaviour
ii. Understanding animal behaviour to improve understandings of
mechanisms underlying human behaviour
iii. To improve our own disease treatments and disorders, this is a basic
requirement to increase life expectation and improve quality of life
,3. The importance of behavioural neuroscience
a. Understand the neuronal and molecular basis underlying normal behaviour
b. Develop an improved mechanistic understanding of pathological behaviour
4. Tinbergen’s four types of ethological questions
, a. Divided in proximate, HOW and ultimate, WHY questions
In house finches, plumage difference:
Proximate, How – what causes the males and females to differ in plumage condition?
Carotenoid based foods that the males actively search for.
Ultimate , Why – why do females prefer red males? Red colored males are less effected by
bacterial pathogen less affected and recovered faster , disease resistance.
Why do males actively search for carotenoid based foods – because much more likely to find
mate increased reproductive succes
, Hormones and Neurobiology
1. Ultimate (evolutionary/ecology) and proximate (physiology/) perspectives
a. Example for better vision (acuity) in robins
i. Natural selection of individuals with better acuity due to improved
reproductive success (better food resources, better predator
avoidance) = Ultimate explanation based on evolutionary processes =
WHY question
ii. Improved sensory function = Proximate (mechanistic) explanation
based on physiology = HOW question
iii. Improved neural processing (e.g. faster detection and discrimination)
= Proximate (mechanistic) explanation based on physiology = HOW
question
iv. Single mutations resulting in beneficial genetic effects that improve
the function of proteins involved in visual perception = Proximate
(mechanistic) explanation based on physiology = HOW question
b. Example for the red vs. yellow colour of finches
i. What causes such a color variation = Proximate question = HOW
question
1. Food containing carotenoids serve as a red color pigment (e.g.
carrots being used as food for salmon instead of natural foods
like crustaceans)
2. Individual colouring and colouring between populations may
vary due to other foraging strategies
3. Males are often more red than females due to the fact that
males forage for food with carotenoids
ii. Why do males but not females actively search for carotenoid-based
foods = ultimate question = WHY question
1. Because bright coloured individuals have a way higher chance
of mating than a lightened individual because they are
preferred by females
2. Red is preferred by females because red animals are less
susceptible for disease than the yellow one
3. Feather degrading bacteria could be an important factor
influencing the ecology and evolution of birds
4. Females lower the risk of pathogen exposure by selecting red-
coloured males
