Unit 5 - Interactions between Individuals Flashcards
pop of different species interact in a …
community
ie.watering hole in africa (elephants/ zebras/ lionking things)
relying on others?
some organisms (animals) rely on others within the community for survival
some birds and rhinoes
individuals within a pop do not
live in isolation
intraspecific vs intrespecific
1) interact w members of their own species
2) members of other species
interspecific interactions
that affect the individual’s survival and reproduction r the product of long term evolutionary adaptation
coevolution
babies
happens when individuals of two or more species influence each other reproductive success
coevolutionary relationship between pairs of organisms take 6 forms
1) predation
2) herbivory
3) mutualism
4) parasitism
5) competition
6) commensalims
predation
in which an organism feeds on another organism
herbivory
in which an organism feeds on a plant
mutualism
in which the relationship is mutually beneficial
parasitism
in which the parasite benefits from the host while reducing the hosts fitness in some way
competition
in which both organisms lose access to resources
commensalism
in which one organism receives benefits from the other organisms without damaging it
Predation effects on interacting pop + ex.
(+/-)
predators gain nutrients and energy prey r killed or injured
ie. northern lynx (pred.)
snowshoe hare (prey)
Herbivory effects on interacting pop + ex.
(+/-)
gain nutrients and energy; plants r killed and injured
ie. white-tailed deer and foliage
mutualism effects on interacting pop + ex.
(+/+)
both pop benefits
ie. honey bee (pollinator) and flowering plants
parasitism effects on interacting pop + ex.
(+/-)
parasites gain nutrients; host r injured or killed
ie. mistletoe attaches to a tree and takes water + nutrients from its host; usually stunts growth but can kill the tree w heavy infestations
competition effects on interacting pop + ex.
(-/-)
both competing pop lose access to some resources
ie. tree in forest competing for light
communalism effects on interacting pop + ex.
(+/0)
one pop benefits; the other is unaffected
ie. moss grows on a tree getting light and nutrients it needs while tree is unaffected
Predation and Herbivory
animals acquire nutrients and energy by consuming other organisms, P and H are likely the most evident examples of coevolution in ecological
specialist
feed on one or just a few types of food
ie. pandas only eat bamboo
or koalas eat leaves
generalist
have broader tastes and r, therefore, most adaptable to changing conditions and varying habitats
ie. Crows eat food from grain to insects to carrion
prey short on food
when prey is scare, animal often take what they can get, settling for food that has a higher cost-to-benefit ratio
Food abundance
when food is abundant, animals may specialize, selecting types of food that provide the largest energy return
defene mechanisms
predation and herbivory have a (-) impact on the species being eaten so animals and plants have evolved mechanisms to avoid being caught and eaten.
types of defence mech
1) camouflage
2) behavioural defences
3) chemical defence
4) mimicry
Camouflage
an organism mimics the patterns environment
ie. rockfish use disruptive colation (breaking up the shape and destroying the outline of an object) to hinder and blend into the background
camiline - fight of competition or attract a mate or stick bug
Chemical defence
an organism is chemically unattractive, either by releasing noxious odours or concentrating poisonous chemicals in its body
ie. Skunks spraying a non-toxic chemical or monarch butterflies use potent plants toxins to make unpleasing to preditors.
Behavioural defence
passive - hiding, freezing, or playing dead
active - fleecing, herding, mobbing, distraction displays
ie. rabbits use both freezing and hiding to avoid being prey
ie. muskoxen her in a tight defensive formation on alert with their horns towards prey
ie. bird mob and harass a predatory to protect young
ie. squid and octopuses use ink clouds
Mimicry
one species enolves to resemble another. there r 2 types
1) batesian 2) mullerian
Batesian mimicry
a palatable or harmless species resembles an unpalatable or poisonous one (model)
ie. harmless drone fly is a BM of the stinging honeybee
Mullerian mimicry
two or more unpalatable species that share common predators look the same
ie. viceroy and the monarch butterflies use MM. they r both unpalatable and look the same
Spines and armour
various animals and plants have hard, thorny, or needle-like structures
ie. north american porcupine releases hairs that have been modified into sharp quills that cause pain and swelling
Population Cycles
interspecific interaction by which pop density of one species (predator) increases while pop density of other species (prey) declines
time lag
exist between responses to predator-prey interactions and their pop size
abt lynx and hare pop
while the L and H pop cycle is often cited as a classic example of pop cycle, snowshoe hare pop exhibits similar 10y fluctuations on islands where lynx are absent
factor affected fluctuations
was the number of pelts purchased by the Hudson Bay Company. fur prices often influence the number of animal traps
recent research abt snowshoe hare pop
caused by complex interactions between the snowshoes hares and there food sources and predators
Interspecific Competition
different species that use the same limiting resources experience ICcom
competing individuals…
may experience increased mortality and decreased reproduction responses similar to those for IC
can occur in two ways
1) interference competition
2) exploitative competition
interference competition
involves aggression between individuals of different species who fight over the same resource(s)
exploitative competition
involves the consumption of shared resources by individuals of different species, where consumption by one limits the resource availability to the other species
Interspecific Competition = Gauses principle
- competitive exclusion
- no to species with similar requirements could coexist in the exactly the same niche indefinitely
- pop of weaker competitor can decline
- change behaviour to survive using diff resources
- one pop could migrate to another habitat
Resource Partitioning
avoidance of/ reduction in competition for similar resources by individuals of different species occupying different non-overlapping ecological niches
Ecological Niches
and organisms’ ecological characteristics, including the use of interaction with ABIOTIC and BIOTIC resources within its environments
- one habitat being address and its niche as occupation
example of ecological niches
lions niche is what it eats, what eats it, the way it reproduces, the temp range it tolerates, its habitat, behavioural responses
fundamental niche
is the biological characteristics of the organism and the set of resources individuals in the pop are theoretically capable of using under ideal conditions
realized niche
the biological characteristics of the organism and the resources individuals in a pop actually use under the prevailing environmental conditions
