EE30 Flashcards
parasitoids
an insect whose larvae live as parasites that eventually kill their host
10% of all species,many are wasps
hyperparasitioids
organism that is a parasite on another parasite (high intimacy,high lethality)
mummy hyperparasitoids
eat hyperparasitioids
parasites
consume parts of the host but typically only one host per lifetime
what do deviations from models show?
other important factors that may need to be considered
how nature=more important than models
“all models are wrong but some are useful”
3 models tackled so far?
1) exponential growth
2) logistic model
3) lotka-volterra model
what is the model WITH predators?
dN/dt =rN - aPN
r=intrinsic growth rate
a=search efficiency/attack rate
P=number of predators
N=prey
what is a?
search efficiency/attack rate
what is P?
number of predators
what is r?
intrinsic growth rate
what is the model for predators with NO PREY (starvation)?
DP/dt =-qP
dP/dt = caPN-qP
q=starvation rate
c=conservation rate
P=predators
N=prey
what is q?
starvation rate
what is c?
conservation rate
what does lotka volterra model tend to produce? give 2 examples
coupled oscillations ie delayed density dependence
IN NATURE
1)lynx and horseshoe hare
2)indian meal moth and parasitoid
neutrally stable cycles where each disturbance initiates new set
Is all cycling in lotka volterra models due to predator prey interactions?
no ie the indian meal moth cycles by itself as does the PIGV (virus) which partly depends on competition
does the snowshoe hare have only one food source and predator?
no it has multiple food sources and predators (not just lynx ie coyote and red fox)
are snowshoe hare pop dynamics more complex or simple than the lynx’s?
more complex
does the lynx only eat horseshoe hares?
No it also eats red squirrels and grey squirrels but the snowshoe hare is its primary food source. It also has competition from other predators
BUT its population dynamics are simpler than the hares’ and it is mostly drivin by the snowshoe hares
what are the wolves and moose on Isle Royle examples of?
predator-prey study by DURWARD ALLEN. could also be a cycle
are cycles common in nature?
no they are rare- models are too simple
How can you make lotka volterra models better?
add complexity to them
if you add the fact some predators are more efficient to lotka volterra models what happens?
competition /interference dampens oscillations
are type 2 functional responses destabilizing?
theoretically yes, but would need to have stronger effects than intraspecific competition
can type 3 functional response be stabilising?
yes can stabilise dynamics (faster increases at low density with prey switching etc)
