ethology & cognitive ecology - brain & cognitive sciences · 1:1 2:1 5:1 fish distribute...
TRANSCRIPT
9/11/2017
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Ethology & Cognitive Ecology
What is the Point?
The point is to show the different forces that
are shaping animal behaviors and to show
you what a complete explanation of a
behavior is like for biologists.
Proximate
Ontogentic
Adaptation Value
Phylogenetic
Cognitive ecology: studies interactions between
information processing abilities and animal fitness.
Ethology: study of natural animal behavior; four levels
Ecology: studies interactions between organisms and
between organisms and their environments.
Understand natural behaviors
Understand cognition as a cause and
consequence of evolution & environment
Biology
Consider the whole animal
Tinbergen’s Ethology
1) Proximate: What immediate events & mechanisms
cause the animal to behave that way?
2) Ontogenetic: What past experiences and genetic
biases cause the animal to behave that way?
3) Adaptation: What is the survival value for behaving
that way?
4) Phylogenetic: What is the history of the animal’s
species that causes it to behave that way?
~1970
• One of most robust species on the planet
• Can remain active without food for one month
• Can go without air for 45 minutes
• Can recover after being submerged underwater for half an hour
Cockroach Cockroach
16 msec before a toad’s tongue
flips out of its mouth, a
cockroach turns and runs.
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Cockroach Cockroach
ProximateWind-sensitive cercal hairs
• Toad produces a tiny gust of wind 41ms before tongue moves
• Cockroach starts to run 3ms after wind
• Tongue hits 10-15ms after running starts (too late to change direction)
• The hairs can detect a tiny gust, as small as 0.03 mph
• The hairs have to be physically moved (glued stiff, no escape response)
Cockroach
Proximate
• If moved, hairs send a neural signal
• Starts at Terminal Ganglion
• Ends at Thoracic Ganglia (escape legs)
• Hairs that sent the signal determine direction of the leg movement (opposite)
• 220 hairs on each cerci
• Move 180 degrees in one of four directions
• Direction of wind determines which
hairs move
Cockroach
AdaptationWind-sensitive cercal hairs
Predator avoidance
Why doesn’t roach run right when it sees a toad?
• Once wind gust is detected the toad is committed to movement
• Toad can’t reprogram tongue at that point
• Roach has better chance of escape
Cockroach
OntogeneticWind-sensitive cercal hairs
How does this behavior develop?
• Born with only 4 hairs (will develop 440)
• Newly hatched cockroach (no experience w/wind) turns away
from wind almost as accurately as an adult (Genetic)
• If an adult loses a cerci, it turns toward wind instead of away
• After 30 days it corrects the behavior (Learning & Rewiring)
Cockroach
Phylogenetic
Orthopteroid insects
~200 million years
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Cockroach• ~200 million years, proliferation of amphibians
• Possible arms race between Orthopteroid insects
& predators
Tentacled Snake
vs. fish
Southeast Asia
Tentacled Snake
vs. fish
C-start response (short for getting into a C shape when startled)
Tentacled Snake
vs. fish
Ken Catania
Tentacled Snake
vs. fish
Ken Catania
“feint”
Tentacled Snake
vs. fish
Ken Catania
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Tentacled Snake
vs. fish
1) Snake has adaptive
advantage over fish
2) Optimal foraging
efficiency
Ken Catania
Proximate & Ontogenetic (individual):
Snakes create a feint which initiates the startle reflex of
the fish (neural mechanism not yet known).
Naïve snakes use feints to startle fish into their mouths
(genetic basis).
Phylogenetic & Adaptive (population):
Contributes to optimal foraging efficiency
Takes advantage of the “rare enemy” effect
Is phylogenetically unique to this species
Tentacled Snake
vs. fish
Cuckoo
vs. reed warbler
Brood Parasitism
In experiments with mock cuckoo eggs, reed
warblers reject some cuckoo eggs.
Cuckoo
vs. reed warbler
Some species visually recognize their eggs very well
Perhaps were once parasitized & developed sharp recognition
skills (blocking parasites)
Spotted
flycatcher
Reed
bunting
Songbird species that are not
currently “cuckooed”
In an experiment with mock cuckoo
eggs, they rejected all cuckoo eggs.
They do not visually recognize their young (at all)
Respond to auditory signals
Cuckoo
vs. reed warbler
They do not visually recognize their eggs well
The cost of accidentally kicking out their own egg is high (each egg
is a major investment of energy and season’s worth of time)
Why reed warblers are victims
Cuckoo
vs. reed warbler
Proximate & Ontogenetic (individual):
After mating (proximate), cuckoo lays eggs in the nest of the
species that raised them (ontogenetic).
Egg coloring genes passed down maternal line (genetic
basis) so cuckoo offspring will produce eggs like the species
that raised them (ontogenetic).
Phylogenetic & Adaptive (population):
Contributes to foraging efficiency, reproductive rate, &
offspring survival (adaptive value)
Is widespread among cuckoo species (common ancestor of
the order) and appears in other bird families (phylogenetic).
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Cuckoo
vs. reed warbler
Phylogenetic
tree (birds only)
Brood parasitism
Ethology
1) Escape response of the cockroach
2) Predatory behavior of the tentacled snake
3) Brood parasitism in the cuckoo
Proximate
Ontogenetic
Adaptation
Phylogenetic
Need an understanding of cognitive skills that underlie
these behaviors (as part of proximate explanation)
1) Cockroach: How well can the roach discriminate predator wind
from non-predator wind? How well can the roach adjust his
escape (eg., if a second strike or second predator is detected)?
2) Tentacled snake: What perceptual cues are important triggers
for the snakes’ feints? How does the snake compute the angle
of his strike?
3) Cuckoo: What cues are important for discriminating imposter
eggs (eg., shape, size, color, smells, timing)? What is the role of
genes versus learning in the species who have defeated brood
parasitism?
Cognitive Ethology (or Cognitive Ecology)
Leslie Real, p. 417
Understand cognitive problems that animals face in their
natural environments.
Proximate & Ontogenetic (individual): Understand the
developmental mechanisms of the cognition & their
genetics, the neural pathways, the hormones, etc.
Phylogenetic & Adaptive (population): Understand the
ecological function and evolutionary history of specific
cognitive abilities
Leslie Real, p. 417
Cognitive Ethology (or Cognitive Ecology)
Would have this goal:
Reading for today: Real, 1993
Cognitive Ethology or Cognitive Ecology
Which food
patch?
Food ratio 2:1
Bee ratio 4:1
If in larger patch there’s:
2x Food
4x Feeders
Then, makes sense to go to smaller patch Reading for today: Real, 1993
Cognitive Ethology or Cognitive Ecology
Which food
patch?
Food ratio 2:1
Bee ratio 1:1If in the larger patch there’s:
2x Food
1x Feeders
Then, makes sense to go to larger patch
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Cognitive Ethology or Cognitive Ecology
Reading for today: Real, 1993
1:1
2:1
5:1
Fish distribute
themselves optimally,
according to expected
payoffs.
Amount of food
Number of competitors
Reading for today: Real, 1993
Cognitive Ethology or Cognitive Ecology
Important to understand animal cognition in order to
explain even the most basic behaviors (foraging,
mating).
Cognition of individual animal in the moment (proximate)
Cognitive development (ontogenetic)
Survival value of cognitive functions (adaptation)
Evolutionary history of cognition (phylogenetic)
Cognitive Ethology or Cognitive Ecology
Rats, mice, and pigeons live successfully in association with our species because of
their generalist, flexible diet.
Generalists identify novel food sources and strategies flexibly, by learning.
Because rats, mice, and pigeons are generalists, they are likely to show types and
degrees of learning that other animals do not.
Cognitive Ethology or Cognitive Ecology
Male and females show no difference in
spatial learning or hippocampal volume
Males and females differ in spatial learning
and hippocampal volume
Males have larger home ranges than females
due to polygynous mating strategy
Males have same size home ranges as females
due to monogamous mating strategy
Cognitive Ethology or Cognitive Ecology
Meadow Voles
Pine Voles
Conclusion
Two main points from the readings:
1) Part of an ethological explanation of
behavior should include cognition (Leslie
Real article)
2) Part of the explanation of cognition should
include evolution and natural environment
(Reuvan Dukas article)
An approach known as cognitive ecology
Interpreting animal behavior requires
multiple levels of explanation (ethology)