lec 15 Flashcards
The three types of species interaction
They are all acted on by
predation, competition, symbiosis
natural selection
succesful predation results in a ___________ for one individual and a __________ for another individual
positive outcome
negative outcome
forms of predation
All are non-lethal but cause harm except for _____ which is usually lethal
- Carnivory, herbivory, parasitism
- Carnivory
Predators are _____ _____ _____ on their prey
strong selective forces
as predators adapt to prey, natural selection shapes _________
the preys defences
coevolution
When one species acts a selective force on another species, and the counter adaptation of the second species in turn affects the first species
reciprical adaptation, like an arms race
various predation strategies
stalking predation
pursuit predation
ambush predation
Physical defenses of plants
spines, thorns, leathery leaves, thick wax
Chemical defenses of plants
send chemical signals to other leaves, poisons
Physical defenses of prey animals
quills or spines, horns, pincers, stingers, tough hides, large size, odour repellents, various defensive behaviors cryptic coloration mimicry store toxins - displays of intimidation - agility to outmaneuver - predator satiation
cryptic coloration
colors or marking that help some organisms avoid detection from predators by blending into their surroundings
chemical defenses of animals
store toxins, brightly colored so predators identify them
aposmatic coloration
toxic animals are brightly colored so predators can identify them
mimicry
attempting to mimic another
Types of mimicry(2)
Batesian
Mullerian
Batesian mimicry
The resemblance of a palatable or harmless species to an unpallatable or venomous species
Mullerian mimicry
two unpallatable species that inhabit the same community mimic each other
- This helps predators learn faster
Predator satiation
synchronous production of progeny to overwhelm predators, resulting in some surviving
Reasons why predators rarely drive prey to extinction
- Predators can switch to other prey when an overexploited prey species becomes scarce
- predators themselves are preyed upon, limiting their impact
- prey have defensive mechanisms to prevent overexploitation
Keystone predator/species
Is a species with a dominant role in shaping the community structure
Their ______ ___ ___ __________ far outweighs their _______ __ _______
- impact on the community
- numbers or biomass
