functional response. fig. 7.20 in molles 2008
TRANSCRIPT
FUNCTIONAL RESPONSE
FUNCTIONAL RESPONSE
FUNCTIONAL RESPONSE
Fig. 7.20 in Molles 2008
Different Light Environments
Adiantum Encelia
Fig. 7.21 in Molles 2008
ForestUnderstory
Plants
Forest CanopyPlants
Functional Response
Fig. 7.22 in Molles 2008
Prey Density
Foo
d In
take
Prey Density
Fig. 7.23 in Molles 2008
Functional Response: Controlled Experiment
Fig. 7.24 in Molles 2008
Functional Response: Natural Environments
Predatory Water Bug
Prey: Mayfly Larva Prey: Isopod
vs.
How do Red-Winged Blackbirds Allocate Energy?1 2
3 4
How do Cacti Allocate Energy?
5 6
9
Optimal Foraging Theory(Derived from Economics)
• Energy Supplies are Limited
• Organisms cannot maximize all functions
• Allocation of Energy is a Compromise between Needs
Bluegill
How do Organisms Selecta Diet?
MODEL FOR ENERGY YIELD: ONE PREY ITEM
E
T=
Ne1E1 - Cs__________________
1 + Ne1H1
ET
=
Cs=
H1 =
Ne1
=
E
T=
(Ne1E1 – Cs)_____________________________________________
1 + Ne1H1 + Ne2H2
+ (Ne2E2 – Cs)
TWO PREY ITEMS
DIET CHOICE: Optimization
Ne1E1 - Cs__________________
1 + Ne1H1
(Ne1E1 – Cs)_____________________________________________
1 + Ne1H1 + Ne2H2
+ (Ne2E2 – Cs)
OR
ONE PREY ITEM
TWO PREY ITEMS
ET
=
ET =
Bluegill
?
Actual Food Availability in the Environment
Prey Length (mm)
Fig. 7.25 in Molles 2008
Bluegill Optimal Diet(Prediction from Theory)
Fig. 7.25 in Molles 2008
Bluegill Actual Diet
Prey Length (mm)
Fig. 7.25 in Molles 2008
Optimal Foraging Theory Observed
Bluegill Diet
Fig. 7.25 in Molles 2008
Optimal Foraging Theory Applied to Plants
LightLevel
Soil Fertility
Fig. 7.26 in Molles 2008
Energy Allocation to Roots
Fig. 7.27 in Molles 2008
Energy Allocation to Roots
1 http://www.coffeecreekwc.org/photos/birds/Red-Winged_Blackbird_(male).jpg
2 http://www.frw.ca/albums/Ponds-and-Wetlands/Projects_Ponds_and_wetlands_ Red_wing_blackbird_nest_in_c.jpg
3 http://www.migrationresearch.org/mbo/id/rwbl/id%20rwbl%20ahy%20f% 20566%20wing%20jul06.jpg
4 http://www.mikephoto.com/content/binary/blackbird-mobbing.jpg
5 http://www.desertusa.com/july96/IMG_0529.jpg
6 http://www.scienceaid.co.uk/biology/ecology/images/cactus.jpg
7 http://www1.istockphoto.com/file_thumbview_approve/3606144/2/istockphoto_ 3606144_saquaro_cactus_skeleton.jpg8 http://www.azcentral.com/help/reprints/pics/animal_1.jpg