Predator-Prey Interactions Flashcards
What is the red queen hypothesis?
“Continuing adaptation is needed in order for a species to maintain its relative fitness amongst the systems it is co-evolving with”
What are the selection pressures in predators?
Selection for improvements in foraging
What are the selection pressures in prey?
Selection for improvements in defences
What are the predator adaptations when searching for prey?
Improved visual acuity
Search image
Search limited area where prey abundant
What are the counter-adaptations by prey when predators are searching for them?
Crypsis (background matching, disruptive patterns and countershading)
Polymorphism
Space out
What are the predator adaptations in recognition of prey?
Learning
What are the counter-adaptations by prey when predators are recognising them?
Masquerade (resemble inedible objects)
Warning signals of toxicity (aposematism, Mullerian mimicry)
Deceive predators by mimicking defended prey
What are the predator adaptations in catching of prey?
Secretive approach
Motor skills (speed and agility)
Weapons of offence
What are the counter-adaptations by prey when predators are trying to catch them?
Signal to predator that it’s been detected Escape flight Startle response: eyespots Deflect attack Weapons of defence
What are the predator adaptions when handling prey?
Subduing skills
Detoxification ability
What are the counter-adaptations by prey when predators are handling them?
Active defence, spines, tough integuments
Toxins
What is camouflage?
All forms of concealment, including strategies that prevent detection (background matching) and those that prevent recognition (masquerade)
What are the two forms of camouflage?
Prevent detection: crypsis (background matching, countershading and disruptive colour)
Prevent recognition: masquerading
What is the purpose of background matching?
It makes searching for the prey more difficult for the predator because they do not match their pre-learned “search image”
What is countershading?
Animal counters the patterns of light and shade with body colouration: put the darker colours on parts of the body that are typically illuminated - enhances cryptic protection
What is disruptive colouration?
Disruptive coloration is a form of camouflage that works by breaking up the outlines of an animal with a strongly contrasting pattern
What is prey polymorphism?
It describes the survival of individual prey animals that are different (through mutation) from their species in a way that makes it more likely for them to be ignored by their predators. It operates on polymorphic species, species which have different forms.
What is apostatic selection?
Where predators overlook rare prey types and consume excess of abundant prey types
What is an example of apostatic selection?
Grouse locust - frequency dependent selection whereby the fitness of morph declines if it becomes too common in the population
What is masquerade?
Masquerade describes the resemblance of an organism to an inedible object and is hypothesised to facilitate misidentification of that organism by it’s predators or its prey.
How can you distinguish between masquerade and crypsis?
With crypsis, detection of the individual in the environment is reduced; With masquerade the predator detects the existence of the potential prey but then misidentifies it as something unattractive to eat.
What are aposematic signals?
Aposematic signals are primarily visual, using bright colours and high-contrast patterns such as stripes.
How do aposematic signals sometimes exploit aspects of predator psychology?
Wariness of certain colours/patterns
Capacity to learn
Memory retention of learnt avoidance
What is an example of when aposematism has been used in conjunction with spatial behaviour?
Brightly coloured species of caterpillars of British butterflies are more likely to be aggregated in family groups than cryptic species
