COMMUNITY ECOLOGY PP 403-404
SYMBIOSIS Close interactions between two (populations) of organisms
Competition (+/-)
Niches overlap and resources are limited a) Intraspecific competition: competition within the same species (population ecology)
b) Interspecific competition: two different species use same food source Fundamental niche: set of resources a population is capable of using under ideal conditions Realized niche: resources a population actually uses due to interactions or competition
c) Competitive exclusion: one species presence causes other species to die, move, or switch to a new food source
d) Character displacement: divergence of characteristics (i. e d) Character displacement: divergence of characteristics (i.e. beaks in finches) e) Resource (niche) partitioning: using specific parts of the same resource (i.e. trees)
Mutualism (+/+)
Commensalism (+/0)
Parasitism (+/-) One species (parasite) lives in or on another species (host) often weakening it but never killing the host
Predation (+/-) One species (predator) eats another species (prey) Types: carnivores, herbivores
Cyclic in nature – ↑ in prey leads to ↑ in predators (and vice versa) PREY: SEA URCHINS PREDATOR: SEA STARS Cyclic in nature – ↑ in prey leads to ↑ in predators (and vice versa) Adaptations in prey for defense against predators
Responses to Predation Camouflage and deceptive markings: Cryptic coloration disguises an animal so it’s less visible to predators or prey
Warning coloration: intended not to camouflage an organism but to make it more noticeable - Bright coloring, scent, or taste to warn potential aggressors
Mimicry: physical (or behavioral resemblance) of one species to another 1. Natural selection of a second moth species favors moths who look like the bad tasting species (bright colors) 2. Color patterns may be similar
Moment of truth defenses: action by prey just before death that is unexpected by predator
Alluring coloration: animals are colored so a predator's attention is drawn to a non-vital part of the prey's body