Transcript Types of interaction - Greenon Local Schools

Types of interaction
In ecosystems
Interspecific Interactions
• Competition
• Predation
• Herbivory (herbivores eating plants or
algae)
• Symbiosis
Competition
• Interspecific – between species
• Competitive Exclusion – local extinction of
a population due to direct competition for
resources with another species
– Example – Barnacles
Competition
• Resource partitioning – differentiation in
niches that allows similar species to
coexist in a community
– Examples
• Warbler species (p. 76 in text) – all feed in different
parts of pine tree
• Different species of lizards have different feeding
habitats in the same area
Predation
• Predator – kills and eats another
• Prey – the hunted (eaten by the predator)
• They both make adaptations to eat and
avoid being eaten through natural
selection
Adaptations of Predators
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Acute sense of smell
Claws
Teeth
Fangs
Stingers
Poison
Predators are usually fast or are
camouflaged
Defenses against predation
(adaptations of prey)
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Camouflage
Mechanical defenses
Chemical Defenses
Mimicry
– Batesian – a harmless species mimics an
unpalatable or harmful model
– Mullerian – two unpalatabel species that
inhabit the same community mimic each
other.
Camouflage
• Grey tree frog and moth
Mechanical Defenses
• Porcupine’s sharp quills
Chemical Defenses
• Poison Arrow frog
Mimicry
• http://waynesword.palomar.edu/lmexe10b.htm#
mimicry
• Batesian – example a snake and a hawkmoth
larva
• Mullerian mimicry – example – cuckoo bee and a
yellow jacket
• Look up your own adaptations – Bring it in for
class tomorrow!!
Keystone Species/Predator
• A species that exerts strong control on
community structure because of its ecological
role or niche
• Thus, they reduce the number of the strongest
competitors in the community, preventing
competitive exclusion of weaker competitors
• Examples
– Sea Star
– Sea otter
Generalized vs. Specialized
Species
• Generalized species – eats a variety of food
• Specialized species – eats one or two species
only
• What is the advantage to a keystone predator of
being specialized to feed mainly on those prey
species that are otherwise the most successful
amount potential prey species?
Answer
• The most competitive prey species
probably represent the most abundant and
dependable food source for the predator
Herbivory (herbivores eating plants
or algae)
• Plant adaptations to avoid being eaten:
– Chemical toxins
• Morphine, nicotine, mescaline, tannins, cinnamon,
cloves, mint
– Spines or thorns
Symbiosis
• Symbiotic Relationship is one between two
or more species that live together in direct
contact.
• Three Types
– Parasitism
– Commensalism
– Mutualism
Parasitism
• A parasite lives on or inside host and
obtains nourishment from the host
• One partner benefits while the other is
harmed.
• Examples: tapeworms, ticks, pathogens
(microscopic parasites)
Commensalism
• One partner benefits without harming the
other
• Examples: algae on sea turtles, barnacles
on whales, and birds that feed on insects
flushed out by grazing cattle
Mutualism
• Benefits both partners in the relationship
• Examples:
– Acacia Tree and ants