extra material chapter 27 Flashcards
symbiosis
species that have close ecological associations with eachother
brood parasites
rely on others to raise their young i.e. canvasback ducks or brown headed cowbirds
encounter rate
abundance of prey
Shannons Index of Diversity vs Evenness Index and what they measure
Index of diversity: measures species richness and evenness
Shannons evenness index: calculates any species evenness
ecological succession is influenced by what
species’ dispersal, maturation, and lifespan differences
latitudinal effects
- differentiation in species distribution based on proximity to or from the equator
Latitudinal Effects:
- decline towards poles
- most in the tropics
1) stable tropical climate
- more generations per year
- faster evolution
- small seasonal changes = less migration
2) maintenance
- stable resources
- tropical climate which supports ecosystem
Robert MacArthur and EO Wilson
- hypothesis: number of species governed by the give or take between 2 processes
= equilibrium theory of island biogeography - number of species is constant
ISLANDS NEAR MAINLAND
- will have high immigration rates because dispersing organisms are more likely to arrive at islands close to point of departure
- number of species on island equals an increased extinction rate
role of the wrasse, cod, and cleaner fish in the mutualistic relationship
wrasse: removes and eats ectoparasites
cod: being cleaned of parasites
cleaner fish: food
defence mechanisms
1) size
2) external vigilance [alert]
3) camouflage
4) evasive action: thwart attack
5) impossible 2 attack: spines + armour
6) chemical signals
7) warnings [aposematic]
8) mimicry
Allen Keast and honeyeater study
- 2 sympatric species fed in a wider range of situations than when you have 6 in the same area
transboundary park
acknowledge differences in political and biological boundaries
nearer islands:
- higher species richness on nearer islands because of its easier colonization
larger islands:
- increased number of species because higher immigration rates and lower extinction rates
- confirmed by Amy Schoener w/ marine organisms study
- confirmed by Daniel Simberloff and EO Wilson with insects at Florida Keys
Mangrove trees
- Daniel simberloff and EO Wilson study
- trees with canopies grew in shallow water and are isolated
- eliminated all the arthropods
RESULTS:
- rapidly recolonized
- decline in species riches
- species composition kept changing
what type of community disturbance causes species richness to be the highest
intermediate frequency and severe intensity
Intermediate disturbance → balance between colonizers and competitors, allowing coexistence and higher diversity
do both sympatric and allopatric species experience character displacement
- no, only sympatric species do because they have the pressure to look more different whereas allopatric species don’t [allopatric species look more similar because there is a lack of pressure to differentiate]
- done in sympatric to reduce competition or avoid hybridization
the number of species found on a large island is
greater than the ones found on a smaller island
a niche is essentially
the role an organism has in its environment
fixed action pattern
sequence of innate, unchangeable behaviours that are once triggered by a specific stimulus and then run to completion without being stopped
behavioural ecology refers to
how environmental factors can influence animal behaviour
Species diversity reflects:
- species richness—how many diff types of species do you have 2. relative abundance—how many of each species do you have
