Animal
ecology
Ilona de Weert
,Inhoud
1. Introduction ..................................................................................................................................... 2
2. Variation in the environment and life histories .............................................................................. 3
3. Feeding guilds, specialists and generalists ...................................................................................... 5
4. Herbivory 2 – the arms race ............................................................................................................ 7
5. Predation ......................................................................................................................................... 8
6. Parasitoids ..................................................................................................................................... 11
7. Parasites ........................................................................................................................................ 12
8. Commensalism and mutualism ..................................................................................................... 14
9. Detritivory ..................................................................................................................................... 15
10. Nutrition in Animal Ecology ....................................................................................................... 17
11. Trade-offs and Bet-hedging ....................................................................................................... 19
12. Reproduction forms................................................................................................................... 21
13. Sex and gender .......................................................................................................................... 22
14. Sex differences .......................................................................................................................... 25
15. Per capita investment................................................................................................................ 26
16. Development and longevity ...................................................................................................... 29
17. Synchronization ......................................................................................................................... 31
18. Dispersal .................................................................................................................................... 33
19. Functional ecological analysis ................................................................................................... 34
20. Heathland fauna and food quality – Guest lecture 1 ................................................................ 36
21. Examples from the field in Animal Ecology – Guest lecture 2................................................... 38
22. Tracking animal movement and behavior – Guest lecture 3 .................................................... 40
23. Scavenging, the importance of carcasses in nature – Guest lecture 4 ..................................... 41
24. Course Animal ecology – summary lecture ............................................................................... 43
1
, 1. Introduction
Basic principles 1
- Feeding
- Not be eaten
- Grow, develop, learn
- Reproduce
Basic principles 2
- All matter that contains energy will be used sooner or later
Basic principles 3
- Variation is self-sustainable
Species traits
- Limitation of the building plan at one hand
- And using different types of variation at the other:
o Tolerance – basic physiology
o Learn (to adapt) – behavioural aspects
o Phenotypical plasticity – reaction norms
o Genetic variation – population effects
Plasticity and genetic variation
- Phenotypical variation or plasticity means:
o Variation in fitness
o Survival probability
o Natural selection
- Although… the selection is only kept in the population when there is a genetical basis.
Variation 1:
Descriptive
- What do we see?
- What is happening?
- Demography (birds were feeding with syphon instead feeding on the whole animal)
Variation 2:
- The genetical basis (quantitative genetics)
- Which traits are subject to selection?
Singular genes or complex reaction norms: = the mapping of the genotype onto the phenotype
as a function of the environment. (What do we see on the population in different
environments?) For instance: when the amount of food is increasing, the size of the organism
is much bigger.
Variation 3:
Trade-offs
- Currency = fitness (but for convenience we charge in energy)
- In the reaction norm of G2 we see less investment in size; apparently more energy of the food
is invested in another trait than in size compared to G1.
Variation 4:
Lineage specific effects
- The construction plan dictates the preconditions (no duplication of arms, legs)
- How small can an egg be, or how big?
- Stearns indicates in chapter 1 that snakes can only lay eggs (as opposed to give birth alive).
Eggs hatch immediately after laying.
- Here the viper is oviparous, just as with the lizards it is the viviparous lizard
2
, - Why do these species keep the eggs inside? Advantage: keeping them warm because when
cooling in the water, the eggs can’t.
Variation 5:
Different types of variation
- How does the environment select?
- What kind of variation arises from the non-living environment?
2. Variation in the environment and life histories
Types of environmental variation
- Predictable variation with predictable amplitude
o Rotation of the Earth around the Sun and tilt of the Earth’s axis of rotation results in
seasons per year.
o Rotation of the Earth around its own axis (24 hours) results in a day and night rhythm.
o Rotation of the Moon around the Earth in combination with the Earth-Sun position
and the Earth rotation gives the tidal rhythm (twice a day).
- Predictable variation with unpredictable amplitude
o Like raining, not predictable in 5 minutes, but in a week it is predictable.
- Unpredictable variation
o Large scale
▪ Earthquakes and tsunami’s
▪ Volcanic eruptions resulting in large amount of ash in the atmosphere and
thus drop in temperature
o Smaller scale
▪ Rain showers, flooding, landslides
▪ Extra cold or warm periods out of the season
▪ Periods of drought
Species that live 100 years, where every 10 years there is a flood -> predictable. When a species live
only one year -> the flood will be unpredictable.
Attenuation of that amplitude
- The vegetation layer dampens in many areas differences in temperatures and moistures
content
- Thus, removal can have irreversible consequences
- Some soils also dry out irreversibly.
Relation environmental variation and life history
- Cycle of environmental variation is only experienced by an induvial when the lifespan exceeds
the cycle
o A tide cycle is already too long for a bacterium
o A summer aphid will never experience a winter
Life history
- Comparison of life histories is always relative
o Related species lay more or less eggs, larger or smaller ones, have brood care or not,
etc
- With one generation per environmental cycle, each generation will have to survive the
unfavourable time: have an obligatory adaption (have to come through the winter as an
individual).
- Option for several generation per cycle.
Classification of biotopes, habitats
- Distinguish between predictable and unpredictable
- Cyclical or non-cyclical (in relation to environmental cycle) in time
3
ecology
Ilona de Weert
,Inhoud
1. Introduction ..................................................................................................................................... 2
2. Variation in the environment and life histories .............................................................................. 3
3. Feeding guilds, specialists and generalists ...................................................................................... 5
4. Herbivory 2 – the arms race ............................................................................................................ 7
5. Predation ......................................................................................................................................... 8
6. Parasitoids ..................................................................................................................................... 11
7. Parasites ........................................................................................................................................ 12
8. Commensalism and mutualism ..................................................................................................... 14
9. Detritivory ..................................................................................................................................... 15
10. Nutrition in Animal Ecology ....................................................................................................... 17
11. Trade-offs and Bet-hedging ....................................................................................................... 19
12. Reproduction forms................................................................................................................... 21
13. Sex and gender .......................................................................................................................... 22
14. Sex differences .......................................................................................................................... 25
15. Per capita investment................................................................................................................ 26
16. Development and longevity ...................................................................................................... 29
17. Synchronization ......................................................................................................................... 31
18. Dispersal .................................................................................................................................... 33
19. Functional ecological analysis ................................................................................................... 34
20. Heathland fauna and food quality – Guest lecture 1 ................................................................ 36
21. Examples from the field in Animal Ecology – Guest lecture 2................................................... 38
22. Tracking animal movement and behavior – Guest lecture 3 .................................................... 40
23. Scavenging, the importance of carcasses in nature – Guest lecture 4 ..................................... 41
24. Course Animal ecology – summary lecture ............................................................................... 43
1
, 1. Introduction
Basic principles 1
- Feeding
- Not be eaten
- Grow, develop, learn
- Reproduce
Basic principles 2
- All matter that contains energy will be used sooner or later
Basic principles 3
- Variation is self-sustainable
Species traits
- Limitation of the building plan at one hand
- And using different types of variation at the other:
o Tolerance – basic physiology
o Learn (to adapt) – behavioural aspects
o Phenotypical plasticity – reaction norms
o Genetic variation – population effects
Plasticity and genetic variation
- Phenotypical variation or plasticity means:
o Variation in fitness
o Survival probability
o Natural selection
- Although… the selection is only kept in the population when there is a genetical basis.
Variation 1:
Descriptive
- What do we see?
- What is happening?
- Demography (birds were feeding with syphon instead feeding on the whole animal)
Variation 2:
- The genetical basis (quantitative genetics)
- Which traits are subject to selection?
Singular genes or complex reaction norms: = the mapping of the genotype onto the phenotype
as a function of the environment. (What do we see on the population in different
environments?) For instance: when the amount of food is increasing, the size of the organism
is much bigger.
Variation 3:
Trade-offs
- Currency = fitness (but for convenience we charge in energy)
- In the reaction norm of G2 we see less investment in size; apparently more energy of the food
is invested in another trait than in size compared to G1.
Variation 4:
Lineage specific effects
- The construction plan dictates the preconditions (no duplication of arms, legs)
- How small can an egg be, or how big?
- Stearns indicates in chapter 1 that snakes can only lay eggs (as opposed to give birth alive).
Eggs hatch immediately after laying.
- Here the viper is oviparous, just as with the lizards it is the viviparous lizard
2
, - Why do these species keep the eggs inside? Advantage: keeping them warm because when
cooling in the water, the eggs can’t.
Variation 5:
Different types of variation
- How does the environment select?
- What kind of variation arises from the non-living environment?
2. Variation in the environment and life histories
Types of environmental variation
- Predictable variation with predictable amplitude
o Rotation of the Earth around the Sun and tilt of the Earth’s axis of rotation results in
seasons per year.
o Rotation of the Earth around its own axis (24 hours) results in a day and night rhythm.
o Rotation of the Moon around the Earth in combination with the Earth-Sun position
and the Earth rotation gives the tidal rhythm (twice a day).
- Predictable variation with unpredictable amplitude
o Like raining, not predictable in 5 minutes, but in a week it is predictable.
- Unpredictable variation
o Large scale
▪ Earthquakes and tsunami’s
▪ Volcanic eruptions resulting in large amount of ash in the atmosphere and
thus drop in temperature
o Smaller scale
▪ Rain showers, flooding, landslides
▪ Extra cold or warm periods out of the season
▪ Periods of drought
Species that live 100 years, where every 10 years there is a flood -> predictable. When a species live
only one year -> the flood will be unpredictable.
Attenuation of that amplitude
- The vegetation layer dampens in many areas differences in temperatures and moistures
content
- Thus, removal can have irreversible consequences
- Some soils also dry out irreversibly.
Relation environmental variation and life history
- Cycle of environmental variation is only experienced by an induvial when the lifespan exceeds
the cycle
o A tide cycle is already too long for a bacterium
o A summer aphid will never experience a winter
Life history
- Comparison of life histories is always relative
o Related species lay more or less eggs, larger or smaller ones, have brood care or not,
etc
- With one generation per environmental cycle, each generation will have to survive the
unfavourable time: have an obligatory adaption (have to come through the winter as an
individual).
- Option for several generation per cycle.
Classification of biotopes, habitats
- Distinguish between predictable and unpredictable
- Cyclical or non-cyclical (in relation to environmental cycle) in time
3
