COMMUNITY INTERACTIONS

the area where an organism lives, Habitat – the area where an organism lives, including the biotic and abiotic factors. The organism’s “address”. They both live in the temperate forest.

the range of physical and biological conditions Niche – the range of physical and biological conditions in which a species lives and the way a species obtains what it needs to survive and reproduce. A species niche includes water, nutrients, food, space, shelter, temperature, moisture, and mates.

They both eat mice but at different time of day. Eagle feeds during the day. Owl feeds at night.

Example of niche: Three species of warblers all live in the same trees and feed on insects. But one species feeds on the high branches, one species feeds on the low branches, and the other species feeds in the middle.

Example of niche:

Specialized Feeding Niches of Various Bird Species in a Coastal Wetland Herring gull is a tireless scavenger Brown pelican dives for fish, which it locates from the air Ruddy turnstone searches under shells and pebbles for small invertebrates Avocet sweeps bill through mud and surface water in search of small crustaceans, insects, and seeds Dowitcher probes deeply into mud in search of snails, marine worms, and small crustaceans Black skimmer seizes small fish at water surface Figure 4.16 Various bird species in a coastal wetland occupy specialized feeding niches. This specialization reduces competition and allows for sharing of limited resources. Flamingo feeds on minute organisms in mud Scaup and other diving ducks feed on mollusks, crustaceans, and aquatic vegetation Louisiana heron wades into water to seize small fish Oystercatcher feeds on clams, mussels, and other shellfish into which it pries its narrow beak Knot (sandpiper) picks up worms and small crustaceans left by receding tide Piping plover feeds on insects and tiny crustaceans on sandy beaches Fig. 4-16, p. 92

Range of tolerance Tolerance- the ability of an organism to survive and reproduce under a range of environmental conditions. # of organisms temperature Organisms become fewer as conditions move toward either extreme of the range.

Range of tolerance Some organisms have a Some organisms have a broad range of tolerance and can better tolerate changes in environmental factors. Some organisms have a narrow range of tolerance and are very sensitive to the smallest change in environmental factors.

Competition When organisms attempt to use the same resource, in the same place at the same time, competition exists. Animals compete for resource such as food, mates, places to live and raise their young. Competition can occur between members of the same species as well as members of different species.

Most Species Compete with One Another for Certain Resources Competition Weeds compete with garden plants Lynx and foxes compete for prey Bison and deer compete for grass

Direct competition between different species almost always Paramecium aurelia Two species competing for the same limited resource cannot coexist in the same place. One species will use the resource more efficiently and thus reproduce more rapidly. Eventually, the best competitor will eliminate the other. Paramecium caudatum Direct competition between different species almost always produces a winner and a loser --- the losing species dies out.

Most Species Compete with One Another for Certain Resources Competition usually involves the ability of one species to become more efficient than another species in getting the limited resource. The other species must: move to another area adapt by shifting its feeding habits or behavior through natural selection to reduce or alter its niche suffer a sharp population decline become extinct.

Competition Natural selection works to modify their niches in an attempt to reduce or eliminate competition

occupy a different niche? Why do these warbler occupy a different niche? Natural selection acts to minimize/decrease competition.

Natural selection acts to minimize/decrease competition. Fruit and seed eaters Insect and nectar eaters Honeycreepers Greater Koa-finch Kuai Akialaoa Amakihi These honeycreepers in Hawaii evolved from a single ancestor. Through natural selection, each species evolved a specialized beak to take advantage of certain types of foods such as specific types of insects, nectar from particular types of flowers, and certain types of seeds and fruits. Kona Grosbeak Crested Honeycreeper Akiapolaau Natural selection acts to minimize/decrease competition. Figure 5.3 Specialist species of honeycreepers: Through natural selection, different species of honeycreepers have shared resources by evolving specialized beaks to take advantage of certain types of food such as insects, seeds, fruits, and nectar from certain flowers. Question: Look at each bird’s beak and take a guess at what sort of food that bird might eat. Maui Parrotbill Apapane Unkown finch ancestor Fig. 5-3, p. 104

Competition Between Two Species of Barnacles

Predation is an interaction in which one animal (predator)  Living Relationships   Predation is an interaction in which one animal (predator) captures and feeds on another animal (prey). Predator – are animals that kill and eat other animals. Prey – the animals that predators eat. Predators can affect the size of prey populations and determine the places prey can live.

Sometimes changes in the population of a single species, called a keystone species, can cause dramatic changes in the structure of the community. Example: sea otters – a keystone species.

Example: sea otters – a keystone species. Sometimes changes in the population of a single species, called a keystone species, can cause dramatic changes in the structure of the community. Example: sea otters – a keystone species. Sea otters prey on sea urchins. Sea urchins in turn, are herbivores that feed on kelp. A century ago, sea otters were nearly eliminated by hunting. As a result, the urchin population skyrocketed. The urchins devoured the kelp forest. The other animals that also live in the kelp forest also disappeared.

Symbiosis is any relationship in which there is Many organisms form living relationships with other organisms. These relationships may enhance the organism’s chance of survival. Symbiosis is any relationship in which there is a close and permanent association among organisms of different species. - - - “ living together”

a symbiotic relationship in which both species benefit.   Mutualism – a symbiotic relationship in which both species benefit. Example: sea anemone and clownfish https://www.youtube.com/watch?v=Xm2qdxVVRm4&index=3&list=PLUytjq5_72or4h1BEfqhenQbjJDtt0Ean https://www.youtube.com/watch?v=8bFSR_4PmCk

Mutualism Protists inside gut of termites

Commensalism – a symbiotic relationship in which one species benefits and the other species is neither helped nor harmed. Example: Grey whales and barnacles

Commensalism Epiphytes

Parasitism – a symbiotic relationship in which one organism derives benefit at the expense of the other. Parasite benefits….host is harmed. Example: Tapeworms and mammals https://www.youtube.com/watch?v=Go_LIz7kTok&index=9&list=PLUytjq5_72or4h1BEfqhenQbjJDtt0Ean https://www.youtube.com/watch?v=vMG-LWyNcAs https://www.youtube.com/watch?v=zSmL2F1t81Q

Parasitism Parasite rarely kills the host Parasite is usually much smaller than the host

Nonnative species/Invasive species Species that normally live and thrive in ecosystem Nonnative species/Invasive species -- Species that migrate into or are introduced (deliberately or accidentally) into an ecosystem -- also called: invasive, alien, and exotic species Some are beneficial: food crops, flowers, animals like cattle, chickens, and fish Some are harmful: compete with native species and reduce a communities native species. They often don’t face their native predators or disease to keep their populations in check and often out-compete the native species. https://www.youtube.com/watch?v=yqLkSHlf5DE

Nonnative/Invasive Species Zebra mussels Invasive species out-compete the native species, they cause decline in the numbers of native species, thereby decreasing biodiversity.