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Species Interactions. Introduction. We have been talking about how populations can change However it is rare in the environment that a species will exist in a population Normally there are other living factors that are in the environment. Predation.
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Introduction • We have been talking about how populations can change • However it is rare in the environment that a species will exist in a population • Normally there are other living factors that are in the environment
Predation • Now it is time to explore how communities can fluctuate and change • One way that a community can fluctuate and change is from predation • In predation, one species will eat all or some of another species
Predation • Most people often think that predators are animals that eat other animals • However, predators can be herbivores • Herbivores eat other organisms and should therefore be considered predators
Predators • Any organism that is eaten is considered prey • Prey organisms often spend a large amount of their life trying to avoid predation
Predator Adaptations • Predators that happen to be the best suited to find and consume their prey are the ones that survive • Rattlesnakes are animals that have an excellent set of adaptive advantages that influence prey
Predator Adaptations • Rattlesnakes have an excellent sense of smell which they use to find their prey • Rattlesnakes also have a very strong venom that can be injected into prey animals • The jaw of the rattlesnakes can unhinge in order to eat large prey
Predator Adaptations • A humming bird is a well adapted predator • A humming bird consumes the nectar of plants • It can beat its wings 10 to 15 times a second • It can also hover in mid air to drink nectar from flowers
Videos • http://www.youtube.com/watch?v=j3mTPEuFcWk • http://www.yourdiscovery.com/video/natures-perfect-predators-great-horned-owl/ • http://animal.discovery.com/videos/fooled-by-nature-hammerhead-shark-hunting-methods.html
Adaptations in Animal Prey • Prey animals may do one of many things when a predator approaches • There goal is to not be eaten • They will use what ever natural abilities they have in order to survive
Adaptations in Animal Prey • Some animals run and hide as fast as they can • These animals are built for speed and agility • As long as the prey animal is faster or more agile then the predator they should be able to survive
Adaptations in Animal Prey • Some animals have false markings or spots that will confuse a predator • The predator might get confused when there is a large group of an animal and not be able to pick out one • Sometimes the markings resemble extra eyes or heads so the predator does not know where the animal is facing
Adaptations in Animal Prey • Some animals hide in plain sight • These animals often try to resemble an object that is inedible • They display a form of camouflage that makes them look like their surroundings
Adaptations in Animal Prey • Some animals have chemical defenses • These defenses can taste or smell terrible or can be deadly • These organisms often have distinct markings and bright colors that let predators know they have chemical defenses
Adaptations in Animal Prey • The final strategy is the mimic a much more deadly animal • Mimicry is when the prey animal will mimic the look of an animal that can defend itself from predators • When a predator sees the animal it will not want to attack it
Adaptations in Animal Prey • http://www.youtube.com/watch?v=HBM88kHnt2E • http://www.youtube.com/watch?v=sfENSyycPQ4 • http://www.youtube.com/watch?v=2x-8v1mxpR0 • http://www.metacafe.com/watch/3129772/mighty_milkweeds/
Adaptations in Plant Prey • Plant prey organisms have to defend themselves differently • Plant prey organisms cannot run from their predators so they normally have different defenses
Adaptations in Plant Prey • Some plants develop physical defenses • These defenses are normally spines, needles, thorns or sticky leaves • These prevent animals from eating them or attempting to get too close to them
Adaptations in Plant Prey • Plants have also developed a variety of chemical defenses • These can be a poisonous sap, bad tasteor irritating rash • These plants are often avoided by predators because of the side effects of eating them
Adaptations in Plant Prey • http://www.howcast.com/videos/22122-How-To-Recognize-and-Avoid-Poison-Ivy
Competition • Interspecific competition is when two different species compete for the same limited resource • Since resources are limited two different species will compete for the resources http://www.youtube.com/watch?v=84bBzAxLXFY
Competition • Lions and Hyenas often will compete for the same prey • Because there are a limited amount of Wildebeests and Zebras Lions and Hyenas will compete over who gets to eat them
Competitive Exclusion • Competitive exclusion is when one species uses a limited resource much more effectively than another species • When this happens, the one species that uses the limited resources more effectively will survive and prosper • The species that does not use the resource as effectively will have drastically lower numbers and my even die out
Competitive Exclusion • We can see competitive exclusion If we put two different type of bacteria in a test tube that share the same niche • After a small amount of time we will see one bacteria have a much higher population • The other bacteria will have a much lower population and will possibly be extinct
Reduced Niche Size • An organism’s niche can be broken up into more manageable chunks • A fundamental niche is the complete range of environments that an organism can live in • A realized niche is the part of the niche that the species generally use
Reduced Niche Size • Generally predators and competition will limit the niche of an organism • The niche of the organism is limited due to these factors • Other organisms that are better suited will be better suited to live in the outer range of the niche
Character Displacement • It is better for predators to be different from one another • If they share too much of the same niche, the predators have a chance of being out competed through competitive exclusion
Character Displacement • The finches that live on the Galapagos Islands are an excellent example • They are all Finches but they all have different beaks they help them do different things • They do not share the same realized niche
Character Displacement • The less similarities among a community, the less chance that a species will die out • The process of predators changing over a period of time is called character displacement
Resource Partitioning • Some predators are in the same area and competing for the same food • When they compete for the same food, it is important to consider where the resources are being used • The differences in location between where predators hunt for a similar resources is called resource partitioning
Resource Partitioning • When you look at a tree there are generally three types of birds hunting for insects • There are birds in the leaves of the trees • There are birds that are on the bark • There are birds that are on the ground
Resource Partitioning • The actual separation of the species makes a more defined realized niche • All of the species are eating a particular type of bug out of a particular tree • However, they are hunting in a different area
Symbiosis • When groupings of organisms are in a close proximity for a long time they can develop relationships • Symbiosis is a long term relationship between two different species
Symbiosis • There are three different types of symbiosis • There are • Parasitism • Mutualism • Commensalism • These three describe what happens when organisms are develop a close relationship
Parasitism • Not all relationships are beneficial to all parties involved • Sometimes there are two organisms in a relationship where only one gains a benefit and one is harmed • Parasitism is when one organism (host) is harmed and one organism (parasite) gains a benefit without immediately killing the host
Parasitism • Parasites can attack a host in a variety of ways • When parasites attempt to harm another organism from the outside of the body they are called ectoparasites • Good examples of this are fleas, leeches, aphids and ticks
Parasitism • Parasites that live inside of the host are called endoparasites • These parasites live inside of their host in the various organs of the body • Examples of this are heartworms, disease causing protistsand tapeworms
Mutualism • Not all close relationships are negative • When both organisms gain some sort of benefit out of a relationship it is called mutualism • This beneficial relationship is seen many places in nature
Mutualism • Probably the most important mutualistic relationship on Earth is between bees and flowers • Flowers provide food for bees in the form of nectar or pollen • Bees carry the reproductive materials for the flower from plant to plant • This allows them to reproduce
Commensalism • Sometimes some organisms have an affect on another organism without a benefit to themselves • Commensalism is when one organism benefits and one organism has not affected • Scavengers are good examples of organisms that have commensalism relationships
Commensalism • A good example of this is water buffalo and cattle egrets • When water buffalo move around as a herd they often scare many bugs, small mammals and small lizards • The cattle egrets follow the buffalo and eat the small animals they scare