Ecological Interactions and Species Relationships

Interspecies competition

competition where species are going after the same resources that let them survive and continue population growth; weeds competing with sunflowers

Limiting factor

the finite factors that determine how big a population can get; food, nutrients in soil

Competitive exclusion

if two species are competing for the same resources, one of them will be more successful and eliminate the other; identified in 1934 by G.F. Gause; microscopic protists in the experiment: P. aurelia vs. P. caudatum

Ecological niche

sum of all resources(biotic and abiotic) that a species uses in its environment; the soil, water, nutrients, etc for a specific plant to grow

Fundamental niche

the ideal situation where a species could live without competition; if one type of plant were to have any resources in a field

Realized niche

where species adapt to their situation so that they can live in the presence of competition; wolves and coyotes coexisting across America

Resource partitioning

similar species settle into separate niches that let them coexist; MacArthur; birds dividing up parts of trees and time using the trees

Character displacement

species follow traits associated with better survival; a species of finches adapting to have small beaks to eat different foods from competing finches

Mutualism

relationship between species that benefits both parties involved; mychorrhizae, a fungal root and plant roots get tangles and give each other nutrients

Commensalism

relationship between species that benefits one party but doesn't harm the other; whales and barnacles

Obligate mutualism

"needy" relationships between species where one species relies on another to survive; termites and microorganisms

Co-evolution

the process by which two species affect the evolutionary development of each other; Ex. Predators and prey species both adapt according to their relationship; wolves hunt in packs, whereas the pronghorn has developed great speed

Predation

any interaction where one type of organism kills another for its energy; Ex. Hawks eating mice

Herbivory

interaction where an organism eats plants or algae to capture their energy; Ex. Bison eating grass

Parasitism

interaction where an organism derives its energy from a host, usually harming it and sometimes killing it in the process; Ex. Hairworms devour the insides of grasshoppers then release chemicals to force the grasshoppers to leap into water, where they die and allow the hairworms to exit and mate

Cryptic coloration

camouflage; helps a species blend into their background; Ex. Stick insects have evolved to look like sticks

Aposematic coloration

warning coloration; bright contrasting colors deter predators; Ex. Fire salamander has yellow and black splotches that make it look unappealing to predators

Mullerian mimicry

many unpalatable species develop similarly unpalatable patterns and colors as a shared defense against predation (such that if a predator recognizes one species as unpalatable, all species with the same coloration/pattern will be spared); Ex. Almost every type of bee/wasp shares an unpalatable black and yellow coloration

Batesian mimicry

mimicry of dangerous, harmful species by harmless species to avoid predation; Ex. Harmless Pieridae butterflies closely resemble toxic Heliconiiae butterflies to avoid predation by birds