6.3 consequences of predation Flashcards
how does forestry increase predation risk for caribou?
-disturbances
-deer and moose feed on leaves
-caribou feed on likin in old pine forest, way from where other prey (and predators) are
what is predator-mediated apparent competition?
-vegetation response that favors alternate prey
-positive numerical response in alternate prey
-positive response in predators
-negative response in caribou
-wolves take on caribou when stumble upon, but not their primary food target (focus on deer and moose)
-apparent=not direct competition but looks like competition. Ex: deer and caribou (feed on different things but have an effect on eachother)
what is apparent competition?
predators can also play a role in what is called “apparent competition”
-an interaction between two prey species, where the presence of one prey has a negative effect on the other, but not the other way around
-ex: when one species has a negative effect on another by bringing to it exposure to a predator (or note, a disease or pathogen)
-depends strongly on the effectiveness of predator
example of apparent competition in banff?
-enough horses to support ten wolf packs
-not see caribou in banff (extinct) because of high number of predators (due to other prey source)
what are keystone predators?
as keystone species, some predators can be an important component of maintaining biodiversity
-has a disproportionate affect on on species compared to how many of them there are
-often predators but not all the time
what is an example of how keystone species affect community structure?
-predators can allow the coexistence of competing prey
how can we test the effect of the predator on community structure?
remove the predator
-mussels are the dominant competitor
-competitive exclusion of barnacles
how do starfish promote coexistence?
-starfish are picky: they prefer mussels (dominant competitor), which allows barnacles (weaker competitor) to coexist
-mussels are unable to reach carrying capacity
what was paines study on pisaster and blue mussels?
-alot of species depend on starfish
what are keystone predators?
-as keystone species, some predators can be an important component of maintaining biodiversity
-keystone species affect community structure disproportionately to their abundance
-picky predators can promote coexistence among competing prey species
-competitive exclusion is prevented when the dominant competitor is the preferred prey
what is E. coli strain K grown in minimal medium + glucose?
what is the graph of number of seals?
what is the graph of apex predators?
BLASTGOWK
what is the condition and trend of aspen, willows and associated species on the northern yellowstone range?
what happened before and after wolves?
