Resource Partition Ani Mardiastuti Giorgii Gause - Russian Gause's Principle (Competitive Exclusion Principle): two species cannot coexist on the same limiting resource Competitive Exclusion (Gause Principle) Two species with identical sociological cannot live together in the same place at the same time If two species coexist, there must be ecological differences between them How to Study Competition 1. Studies on the ecological of sympatric closely related species 2. Character displacement 3. Studies in “ incomplete “ flora and fauna → niche shifts 4. Taxonomic composition of communities Consequences of Competition • Resource partitioning (segregation) Species avoid competition by partitioning resources and habitats among themselves • Character displacement Sympatric Competitors → “create” ecological difference by : 1. Exploit different habitat/microhabitat (different spatial utilization) 2. Eat different food 3. Active at different times (different patterns of temporal activity) spatial (horizontal, vertical), temporal, food Closely related species Congeneric species • Similar morphology • Similar physiology • Similar behavior • Similar ecological aspect Intense competition Competition is more intense between congeneric species Pycnonotus aurigaster kutilang vs. Pycnonotus goiavier terucuk Spatial Partition Spatial Partition: Vertical Position Temporal partition: predators hunt at different times of the day Food Partitiion The frequency distribution of depths at which clams of different size classes are found in intertidal mudflats Distribution of several shorebirds feeding in intertidal mudflats Guild • A group of species that exploit the same class of environmental resources in a similar way • Usually related to feeding techniques • Habitat niche guild • Common field studies in birds, expanded to many other taxa Guild Classification Guild in Spiders Niche Shift The distribution of two competing species is often a function of both competition and physiological tolerances Study on taxonomic composition of communities .