54-species Interactions Flashcards
Species interactions
Can be…
- beneficial (+)
- detrimental (-)
- have no effect (0)
Interspecific interactions
Interactions between individuals of different species
- predation
- competition
- positive interactions
- Amensalisms
Trophic/nontrophic
Involves feeding/doesn’t involve feeding
Predation
- one species (predator) eats another (prey)
- (+,-)
- trophic
- 3 versions
Carnivory
- animal eats animal (prey dies)
- leads to predator strategies…
- active pursuit (speed, claws)
- sit & wait (intelligence, mechanical advantages)
- and prey strategies
- speed to flee -avoiding detecting
- flight -chemical defenses
- mechanical defenses
Avoiding detection
- Crypsis
- camouflage making prey hard to see
Chemical defenses
- many small or weak species have evolved chemical defenses
- aposematic colors
- warning signals (in color) that tell predators not to eat certain organisms with chemical defenses
Mimicry
(Arises from aposematic colors)
Batesian
-harmless species looks like a dangerous one
Mullerian
-two or more dangerous species resemble each other
Herbivory
- animal eats plant (prey doesn’t always die)
- leads to plant adaptations…
- spines/thorns
- toxins
- bad taste
- and to animal adaptations…
- tough mouth
- grinding teeth
- toxin resistance
Parasitism
- parasites are much smaller than hosts
- parasites have evolved…
- evading immune systems
- movement between hosts
- hang onto hosts
- low virulence
- hosts have evolved…
- stronger immune systems
- systems to decrease parasite load
Micro parasites
- much, much smaller than host
- many generations may reside within a single individual
- many cause symptoms of disease and are considered pathogens
Macro-parasites
- larger than micro-parasites
- ectoparasites live outside body of host
- endoparasites live in body of host
Competition
- individuals compete for a resource that limits their growth and survival
- (non trophic)
- (-,-)
- often asymmetrical (one species is more negatively effected than another)
niche
The set of all biotic and abiotic conditions which an individual needs to grow, survive, an reproduce
Fundamental niche
- the range of all resources which are available to use by a species
- when species share similar fundamental niches, they will compete for some resources
Realized niche
-the range of all resources an organism actually does use
Competitive exclusion
- one species prevents another from using a certain resource
- inferior species doesn’t survive
Competitive coexistence
- when species share a resource, and in turn both survive
- resource partitioning
- character displacement
Interference competition
When one species directly interferes with or excludes another species’ access to a limiting resource
Exploitation competition
When a limiting resource is available to all competitors but the outcome of the interaction depends on how efficiently each species uses the limiting resource
Resource partitioning
- sharing a limited resource by using the resource in different ways
- coexistence achieved through specialization
Character displacement
-phenomena in which species who compete for the same limiting resource diverge in morphology or behavior
Positive interactions (facilitations)
- at least one species benefits, none are harmed
- trophic or nontrophic
- Mutualism (+,+)
- commensalism (+,0)
- obligate/facultative
Amensalisms
- one species is harmed and the other is unaffected
- usually indirect
- (-,0)
