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

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1 2 3 4 5 6 7 8 9 10 11 12

Station (1=downstream)

Fis

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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