organism population Community Ecology community ecosystem biosphere

Community Ecology Community Community Ecology all the organisms that live together in a place interactions Community Ecology study of interactions among all populations in a common environment To answer: In what way do the populations interact?

Niche An organism’s niche is its ecological role habitat = address vs. niche = job High tide Competitive Exclusion If Species 2 is removed, then Species 1 will occupy whole tidal zone. But at lower depths Species 2 out-competes Species 1, excluding it from its potential (fundamental) niche. Species 1 Low tide Chthamalus sp. Species 2 Fundamental niches Realized niches Semibalanus sp.

Niche & competition Competitive Exclusion No two similar species can occupy the same niche at the same time

Symbiotic Relationships Symbiosis- two species living together 3 Types of symbiosis: 1. Commensalism 2. Parasitism 3. Mutualism Cleaning shrimp

Symbiotic Relationships Commensalism- one species benefits and the other is neither harmed nor helped Ex. orchids on a tree Epiphytes: A plant, such as a tropical orchid or a bromeliad, that grows on another plant upon which it depends for mechanical support but not for nutrients. Also called xerophyte, air plant.

Symbiotic Relationships Commensalism- one species benefits and the other is neither harmed nor helped Ex. polar bears and cyanobacteria You can see here that this polar bear is no longer white.

Symbiotic Relationships Parasitism- one species benefits (parasite) and the other is harmed (host) Parasite-Host relationship

Symbiotic Relationships Parasitism- parasite-host Ex. lampreys, leeches, fleas, ticks, tapeworm

Symbiotic Relationships Mutualism- beneficial to both species Ex. cleaning birds and cleaner shrimp The Egyptian plover takes insects from the backs of buffaloes, giraffes and rhinos. The plover has also been observed taking leeches from the open mouths of crocodiles! In this association the plover receives a supply of food and the other animal rids itself of unwelcome pests

Symbiotic Relationships Mutualism- beneficial to both species Ex. lichen The Egyptian plover takes insects from the backs of buffaloes, giraffes and rhinos. The plover has also been observed taking leeches from the open mouths of crocodiles! In this association the plover receives a supply of food and the other animal rids itself of unwelcome pests

= 1 species Type of relationship Species harmed Species benefits Species neutral Commensalism Parasitism Mutualism = 1 species

Species interactions Symbiotic interactions competition (-/-) compete for limited resource competitive exclusion! predation / parasitism (-/+) mutualism (+/+) lichens (algae & fungus) commensalism (+/0) barnacles attached to whale

…not very funny for a clown fish Symbiosis mutualism +/+ …not very funny for a clown fish commensalism +/0 predation +/- competition -/-

What relationship is this? clown fish & sea anemone ants & acacia impala & oxpeckers

Predation drives evolution Predators adaptations locate & subdue prey Prey adaptations elude & defend Predation provides a strong selection pressure on both prey & predator horns, speed, coloration spines, thorns, toxins Predation provides a strong selective pressure on prey populations. Ay feature that would decrease the probability of capture should be strongly favored.

Anti-predator adaptations Hide from predators avoid detection camouflage Warn predators advertise how undesirable you are as prey

Defense mechanisms Camouflage coloration blends into surroundings whipporwill frog lizard lizard toad

Mimicry green parrot snake harmless species mimics (copies) a harmful species green parrot snake Hawkmoth larva puffs up to look like poisonous snake hawkmoth larvae

Coral snake is poisonous What kind of mimicry? Coral snake is poisonous King snake is not Red on yellow, poison fellow; red on black, safe from attack

Feeding Relationships Predator-prey relationships Parasite-host relationships Flowers & pollinators Long term evolutionary adjustments between species

Competition Species compete for limited resources