1. Curvilinear isoclines might be more realistic

2. Mutualism Equations (pp. 234-235, Chapter 11)
dN1 /dt = r1 N1 ({X1 – N1 + a12 N2 }/X1) dN2 /dt = r2 N2 ({X2 – N2 + a21 N1 }/X2) (X1 – N1 + a12 N2 )/X1 = 0 when N1 = X1 + a12 N (X2 – N2 + a21 N1 )/X2 = 0 when N2 = X2 + a21 N1
If X1 and X2 are positive and a12 and a21 are chosen
so that isoclines cross, there is a stable joint equilibrium
Intraspecific self damping must be stronger than interspecific positive mutualistic effects.

3. N2*
N1*
Note: when together, both species reach higher equilbrium population density

6. Evidence of Competition in Nature. often circumstantial. 1
Evidence of Competition in Nature often circumstantial 1.Resource partitioning among closely-related sympatric congeneric species (food, place, and time niches) Complementarity of niche dimensions 2. Character displacement 3. Incomplete biotas: niche shifts 4. Taxonomic composition of communities

7. Major Foods (Percentages) of Eight Species of Cone Shells, Conus,
on Subtidal Reefs in Hawaii
__________________________________________________________
Gastro- Entero Tere- Other
Species pods pneusts Nereids Eunicea belids Polychaetes
flavidus
lividus
pennaceus 100
abbreviatus
ebraeus
sponsalis
rattus
imperialis

8. MacArthur’s Warblers (Dendroica)
Robert H. MacArthur

9. John Terborgh

10. John Terborgh

11. Time of Activity Seasonal changes in activity times

12. Complementarity of Niche Dimensions, page 276
Anolis
Thomas W. Schoener

14. Prey size versus predator size

15. Peter R. Grant
David Lack

16. Character Displacement in Hydrobia mud snails in Denmark
Snail shell length, mm

17. Hutchinsonian ratios among short wing Accipiter hawks
Thomas W. Schoener

21. Hutchinsonian ratios among Australian Varanus lizards