Animal Ecology summary
L1 introduction
Basic principles of ecology:
- Feeding
- Not to be eaten
- Grow, develop and learn
- Reproduce
All matter that contains energy will be used sooner or later
Variation is self-sustainable
Species traits: limited by building plan,
depend on variation in:
- Tolerance
- Adaption
- Phenotypical variance = plasticity
= variation in fitness, survival probability and natural selection
- Genetic variation
Lineage specific effects = inherited characteristics
Trade-offs = chose what to invest in
Currency: fitness, or energy for convenience
L2 Environment & life history
Types of environmental variation:
- Predictable with predictable amplitude
o Rotation and tilt of earth -> seasons, day/night, tides
- Predictable with unpredictable amplitude
- Unpredictable
Surface water: 2/3 of earth cover,
Dampens temperature fluctuations
Vegetation (forest) also dampens temperature and moisture fluctuations -> warmer inside forest
Biotopes/habitats:
- Predictable vs unpredictable
- Cyclical vs non-cyclical in time
- Continuous, fragmented or isolated in space
Quadrant of Southwood:
HERE SOMEWHERE ELSE
NOW Continuous generation Dispersal
LATER Diapause Diapause + dispersal
,MacArthur & Wilson:
r-select = rate of increase spectrum K-select = carrying capacity
many offspring invest a lot in offspring
Grime:
= Stress tolerating
= Ruderal strategy = Competitive
Objections to both: hard to measure and compare
Use life history traits: always relative
L3 Feeding guilds, specialists and generalists
Niche = multidimensional space of environmental factors/resources with a given parameter (n)
Fundamental niche = if not other species present
Realised niche = when there is competition, the remaining dimensions
Habitat = subset of niche referring to the place where the species lives
Specialist = species with a narrow width on some of the dimensions of its niche
Due to competition pressure
Benefits: limited investment in for ex. digestive enzymes, easier to get past defence
Disadvantage: limitation in food
Generalist = species with large niche width for most dimensions
, Leads to equilibrium
Leads to heterozygous and then speciation
Trade-off = trait costs extra energy
Herbivory is a trade-off -> hard to digest
Plant defence:
- Constitutive defence = basic defence = always on, low cost
- Induced defence = only when necessary (under attack), higher costs
Chemical protections:
- N-containing components: costly, only on nutrient rich sites
o Alkaloids
o glycosids
- C-containing components
o Phenols
o Furanocoumarins
o Terpenoids
L4 Herbivory arms race
What herbivores want:
- Nitrogen for building blocks
- Essential amino acids
- Vitamins & minerals
Herbivores bypass defence -> plants adapt: other defence or combination of multiple
Plants communicate to other plants & parasitoids
-> induce defence in other plants, parasitoids eat predator
L5 Predation
Predations:
- Two individuals from different populations
- Leads to desth of prey (usually)
- Predator population grows, prey population decreases
dN r n∗N∗K n−N
Prey population growth: =
dt Kn
With N is individuals in population, rn is intrinsic growth rate and Kn Is the carrying capacity
L1 introduction
Basic principles of ecology:
- Feeding
- Not to be eaten
- Grow, develop and learn
- Reproduce
All matter that contains energy will be used sooner or later
Variation is self-sustainable
Species traits: limited by building plan,
depend on variation in:
- Tolerance
- Adaption
- Phenotypical variance = plasticity
= variation in fitness, survival probability and natural selection
- Genetic variation
Lineage specific effects = inherited characteristics
Trade-offs = chose what to invest in
Currency: fitness, or energy for convenience
L2 Environment & life history
Types of environmental variation:
- Predictable with predictable amplitude
o Rotation and tilt of earth -> seasons, day/night, tides
- Predictable with unpredictable amplitude
- Unpredictable
Surface water: 2/3 of earth cover,
Dampens temperature fluctuations
Vegetation (forest) also dampens temperature and moisture fluctuations -> warmer inside forest
Biotopes/habitats:
- Predictable vs unpredictable
- Cyclical vs non-cyclical in time
- Continuous, fragmented or isolated in space
Quadrant of Southwood:
HERE SOMEWHERE ELSE
NOW Continuous generation Dispersal
LATER Diapause Diapause + dispersal
,MacArthur & Wilson:
r-select = rate of increase spectrum K-select = carrying capacity
many offspring invest a lot in offspring
Grime:
= Stress tolerating
= Ruderal strategy = Competitive
Objections to both: hard to measure and compare
Use life history traits: always relative
L3 Feeding guilds, specialists and generalists
Niche = multidimensional space of environmental factors/resources with a given parameter (n)
Fundamental niche = if not other species present
Realised niche = when there is competition, the remaining dimensions
Habitat = subset of niche referring to the place where the species lives
Specialist = species with a narrow width on some of the dimensions of its niche
Due to competition pressure
Benefits: limited investment in for ex. digestive enzymes, easier to get past defence
Disadvantage: limitation in food
Generalist = species with large niche width for most dimensions
, Leads to equilibrium
Leads to heterozygous and then speciation
Trade-off = trait costs extra energy
Herbivory is a trade-off -> hard to digest
Plant defence:
- Constitutive defence = basic defence = always on, low cost
- Induced defence = only when necessary (under attack), higher costs
Chemical protections:
- N-containing components: costly, only on nutrient rich sites
o Alkaloids
o glycosids
- C-containing components
o Phenols
o Furanocoumarins
o Terpenoids
L4 Herbivory arms race
What herbivores want:
- Nitrogen for building blocks
- Essential amino acids
- Vitamins & minerals
Herbivores bypass defence -> plants adapt: other defence or combination of multiple
Plants communicate to other plants & parasitoids
-> induce defence in other plants, parasitoids eat predator
L5 Predation
Predations:
- Two individuals from different populations
- Leads to desth of prey (usually)
- Predator population grows, prey population decreases
dN r n∗N∗K n−N
Prey population growth: =
dt Kn
With N is individuals in population, rn is intrinsic growth rate and Kn Is the carrying capacity
