Community Interactions • A biological community is a collection of populations of different species that interact with each other a pond = insects, fish, algae, animals, plants, frogs all live close enough to interact COMMUNITY INTERACTIONS PREDATION COMPETITION SYMBIOSIS COMPETITION • when different species require the same resources to survive and reproduce Competition for Food Competition for Space Competition for sunlight PREDATION • when one species captures and consumes another for energy • Predator: “the hunter” • Prey: “the hunted” SYMBIOSIS • the process of living together TOGETHER PROCESS SYMBIOSIS MUTUALISM PARASITISM COMMENSALISM MUTUALISM (+/+) Mutualism: both species benefit from the relationship Cleaner birds and crocodiles: Birds eat decaying meat stuck between crocodile teeth Clown fish and anemones: Clown fish chases away fish that like to eat anemones while the clown fish are protected from predator fish by the stinging tentacles of the anemone Lichens (fungus/algae): the fungi provides structure and protection for the algae and also obtains water and mineral; algae makes food for the fungi through photosynthesis COMMENSALISM (+/ø) • Commensalism – one species of the relationship benefits and the other is neither helped nor harmed Triggerfish creates feeding opportunities for smaller fish by moving large rocks too big for them to shift themselves. As the whales travel, the barnacles gain access to nutrientrich waters, while the whale neither benefits nor is harmed by its riders Bugs (non parasitic) living on large herbivores like water buffalo. Birds cleaning non-parasitic bugs off of the water buffalo PARASITISM (+/-) • Parasitism- one organism (parasite) depends on another (host) for nourishment or other benefit. • Some species live within the host Ticks are parasites that feed on the blood of their hosts often carrying diseases Tapeworm eggs are usually eaten in contaminated meat and then mature in the animal’s intestines CUCKOO BIRD WARBLER BIRD PREDATION HOW Mr. Kim & Chicken Wings Mr. Kim hunts out and destroys chicken wings for energy COMMENSALISM HOW Mr. Kim & his dogs Mr. Kim drops food while he eats (0) and the dogs pick up the scraps (+) PARASITISM HOW Mr. Kim & his wife Mr. Kim loses money (-) while bae gets food & jewelry (+) Keystone Species • A keystone species is a species that plays a critical role in maintaining the structure of an ecological community • Removing the keystone species, the food web can be adversely affected • “Holds the community together” • Plays an important role in stabilizing population sizes in the community Keystone Species Pacific Northwest Intertidal Zone Removing the Pisaster starfish caused a loss of diversity in the intertidal zone of the Pacific Northwest. Being a top predator, Pisaster kept lesser organisms in the food chain within stable limits. When removed, these populations flourished and crowded out other species. Within ten years, seven species disappeared from the community = biodiversity loss. Habitat: a place where an organism lives • Habitats include both biotic and abiotic factors like shelter, water, food and space. • Examples: forest desert pond tidal pool large intestine neighborhood street Niche: an individual’s ecological role • A niche describes the way of life of a species. Each species is thought to have a separate, unique niche in a habitat • A niche includes its place in a food web – Are they a food source for others? Top carnivore? • A niche includes how the organism lives, eats, reproduces • How they uses environmental conditions, like sunlight, temperature, and food. HABITAT vs NICHE FLOWERS EXIT TICKET 1) 2) 3) 4) What is a community? Name the 3 types of community interactions. Name the 3 types of symbiosis. How do mutualism, commensalism, and parasitism differ? 5) What is a Keystone species?