Transcript File - Mr. Shanks` Class

E. INTERACTIONS WITHIN COMMUNITIES
1. Interspecific competition
a. 2 or more species struggling for the same resource
b. both species will lose
c. eg.
2. Predation
a. one species kills and eats another
b. the predator gains but the prey loses
c. but if the predator eats too many prey, then
the prey runs out & predator also loses
n
u
PREY
m
b
e
PREDATOR
r
time
d. note:
there is always more of the prey
the two cycles are out of synch as there is a
delay in the effect
as predator #’s increase, prey #’s fall;
as prey #’s fall, predator #’s fall
3. Defense mechanisms
a. camouflage – don’t get seen by predator OR prey
eg. rabbit OR bobcat
b. toxins
– produce or accumulated
eg. sea slug
eg. Monarch butterfly
c. mimicry- pretend to be toxic
eg. Viceroy butterfly
Not toxic, but appears to be
eg. Monarch butterfly
Wings are toxic.
d. distractors – trick the predator in some way
large eyespots distract the predator
4. Symbiosis
a. mutualism
- both gain
eg. oxpecker & giraffe
Oxpecker gets to eat insects and
giraffe gets rid of parasites
b. commensalism
- one gains, one unaffected
eg. algae on back of turtle
Algae gets a sunny perch and turtle which is
already green, gets no benefit, nor any harm.
c. parasitism
- one gains, one loses
eg. mosquito and you
The mosquito gets blood for its eggs and
you lose blood and may get a disease.
what type of defense is this?
hoverfly
rattlesnake
The rattlesnake has to
warn off animals so it
does not have to use its
TOXIN.
The bee has warning colours as its sting is ‘toxic’. But the
hoverfly has no sting and so it is a MIMIC.
Questions D
from pg 8.