5 Basic types of species interactions
2
1?
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Competition is important...just not as important as predation
Competition ...common use of a limited resource
limited
food habitatWhat can be limiting....?
food
habitat
FUNDAMENTALREALIZED
A
B
2 dimension, but there are more....
Between and within species??Intraspecific competition
Interspecific competition
How do we see it or measure it?
Individual Responses
•Behavior – feeding rate
•Physiology – growth rate
•Morphological – body size
Population responses
•Abundance
•Distribution
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3 types of competition??
Interference competition Exploitation competition
Apparent competition
Interference competition - occurs directly between individuals via aggression etc. when the
individuals interfere with foraging, survival, reproduction of others, or by directly preventing their physical establishment in a portion of the
habitat.
A B(-)
(-)
Exploitation competition - occurs indirectly through a common, limiting resource, which acts as an intermediate. Ex. depletes the amount of
food or fill up all the available space.
A B(-)
(-)
R
- + + -
Apparent competition - occurs indirectly between two species which are both preyed
upon by the same predator.
A B
P
- +
A B
P- +
-+
-
http://video.google.com/videoplay?docid=-6431936272692514162
Competition's role in ecology and evolution
Resource partitioning
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Resource Gradient
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Resource Gradient
"species packing"
Cichlids exhibit remarkable evolutionary convergence. Similar ecomorphs have evolved repeatedly within different cichlid assemblages. All of the cichlids in the left-hand column are from Lake Tanganyika. All of the cichlids in the right-hand column are from Lake Malawi, and are more closely related to one another than to any species within Lake Tanganyika. Note the similarities among color patterns and trophic morphologies.
Lake Tanganyika Lake Malawi
Utilize resources along a gradient (See Wooton)– Food particle size– Temperature– Habitat
0
10
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30
40
50
60
70
80
90
100
1 2 3 4 5 6 7 8 9 10 11 12
Station (1=downstream)
Fis
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bu
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Sculpin
Dace
Examples: Classic Werner and Hall Experiments
Bluegill
Green Sunfish
Pumpkinseed
Examples: Ciscoes adaptive radiation (Lindsey 1981)
Modeling Competition• Lotka-volterra model• Competition coefficients• The equations• What the hell is an isocline, anyway?
– 4 graphs. See Molles
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Exotics species that affect the ecology of native Wisconsin FishesPelagic planktivores - Alewife, Rainbow smelt, white perchBenthic insectivores – round goby, common carp
Pelagic piscivores – Pacific salmon, brown trout
Pelagic/benthic parasite – Sea lamprey
Stream insectivores – brown trout, rainbow trout
Pelagic filter-feeders – silver carp, bighead carp
Exotics fish utilize different habitats
And a variety of food sources
How do they get here?
Ships ballast water
Aquaculture
People
Canals
Ballast water
Alewife
white perch
Round goby
Canals
Sea lamprey
Rainbow smelt
Intentional Stocking
Pacific Salmon
Brown trout
Rainbow trout
Common carp
Rainbow smelt
Aquaculture
Silver carp
Bighead carp
Species Earliest Record Unintentional or Intentional Transport or Release Mechanism(s)
Alewife <1953 Unintentional Canals
American eel 1970 Unintentional Canals
Atlantic salmon 1972 Intentional Stocked
Brown trout 1883 Intentional Stocked
Brook silverside 2002 Unintentional Unknown
Chinook salmon 1967 Intentional Stocked
Coho salmon 1966 Intentional Stocked
Common carp 1897 Intentional Stocked
Eurasian ruffe 1986 Unintentional Ballast Water
European flounder 1981 Unintentional Ballast Water
Fourspine stickleback 1986 Unintentional Ballast Water or Live Bait
Freshwater drum ? Intentional Stocked (assumed)
Gizzard shad ? Unintentional Live Bait or Aquaria
Goldfish 1975 Intentional Stocked (assumed)
Kokanee salmon ? Intentional Stocked (assumed)
Pink salmon 1956 Intentional (unplanned) Stocked
Rainbow smelt 1930 Unintentional Canals
Rainbow trout 1895 Intentional Stocked
Round Goby 1995 Unintentional Ballast Water
Sea lamprey 1938 Unintentional Canals
Splake ? Intentional Stocked
Threespine stickleback 1987 Unintentional Ballast Water
Tubenose goby 2000 Unintentional Ballast Water
White Perch 1986 Unintentional Ballast Water
LAKE
SUPERIOR
3 aspects that make them so successful...?High fecundity – lots of eggs / individual
Excellent competitors – better at gaining resources then native species
Exploit a less well used resource
http://people.cornell.edu/pages/gbs27/gbssmb.html
Detrimental to sport fisheries... round gobies to smallmouth bass nests
http://www.youtube.com/watch?v=2ChwJiKKBdA
Detrimental to ....life as we know it on all lakes and rivers