General Flashcards
% energy that goes through biomass
10%
Why is prey behaviour studied more?
Easier to assume fixed risk of predation
Prey easier to observe
Encounter rates matter more when …
Densities are limited
Sensory ranges are limited
Random walk explanation
Step length at time (t) uncorrelated to step length at t+1
Variants of random walks
Brownian motion
Correlated random walk
Lévy flight
If slope of line (u) near …, = Lévy flight
2
What can prey do to reduce encounter rate when no information about predators
Reduce movement
Use refuges
Aggregate
What can prey do to reduce encounter rate when has information about predators
Move elsewhere
Or do same as if don’t have cues
First person to write about theories of matching the background
Abbott Thayer
Who was Thayer ridiculed by?
Theodore Roosevelt
Who came up with the most popular theory of how colour patterns form?
Alan Turing
What do we need to describe the background in terms of?
Orientation and spatial frequency of edges
Colour of surfaces
“No colour scheme whatever is of much avail to animals when they move, unless movement is very slow and cautious”
Who said this?
Theodore Roosevelt
How to conceal motion
Move slowly
Move in short bursts
Match the motion of background
Give up and use a different tactic
What does disruptive colouration involve?
Colour patches intersecting body outline
Differential blending
Maximum disruptive contrast
What group identified principles of what the brain does to group features together and recognise objects?
Gestalt school of psychology
What are the principles of what the brain does to group features together and recognise objects?
Proximity Similarity Continuity Symmetry Area Closure
Other reasons to be countershaded
Protection from UV
Viewed against different backgrounds from below vs above
Save cost of pigmentation where not needed
First person to use term “search images”
Luuk Tinbergen
How detection and recognition separated
Figure-ground segmentation
Target-distractor discrimination
Who came up with Batesian mimicry?
Henry Walter Bates
How does imperfect mimicry exist?
Differences in perception from humans Lots of alternative profitable prey Costs of misclassifying as tasty very high Rapid decision-making needed Biases in learning
Ways of quantifying background complexity / visual clutter
Sub-band entropy
Feature congestion metrics
Leader on feature congestion metrics
Ruth Rosenholtz
Who noticed the idea of aposematism and when?
Alfred Russel Wallace (1867)
Who coined the term aposematism and when?
Poulton (1890)
Who originally cam up with synergistic selection?
Dawkins
Why be conspicuous (aposematism)?
Easy to discriminate from background - can be seen from afar, facilitates decision making
Easy to discriminate from palatable prey - facilitates learning, facilitates memory
Why often contrasting colours (aposematism)?
Increases visibility independent of background
Increases distinctiveness from palatable prey
Increases memorability independent of background
Who claimed credit for WW1 dazzle?
Kerr
Thayer
Norman Wilkinson
Another term for startle displays
Deimatic behaviour
Who coined the term protean behaviour and when?
Humphries and Driver (1970)
Counteracting the confusion effect
Shift attention toward prey capture
Get experience
Target odd prey
Attack prey on group edge
Run as soon as predator detected when…
Predators search slowly Predators have high prey detection rate There's a large advantage to having head start Low energetic fleeing cost High capture success
How can type 2 functional response be exploited by prey?
Predator swamping
Unpredictable high-density emergence of individuals
Snowshoe hare population cycle (how many years)
8-11 years
