Figure 4. All qualitative outcomes of the optimal foraging strategy (8) and (10) with parameters 
.
In these plots, the energetic value 
of resource B varies in the interval from 
to 
(i.e. 
). The critical values of 
are 
; 
; 
; 
. The arrows in each panel indicate the direction of increasing energy intake per unit time at points in the unit square. In each case shown, these arrows lead to a single vertex indicated by the filled in circle which corresponds to the optimal foraging behavior (and unique NE). (a) For 
, 
and 
. Thus 
and 
. (b) For 
, 
and 
. Thus 
and 
. The dashed line denotes 
As 
increases, 
moves to the right until it coincides with the vertical line 
when 
. At this critical value of 
(not shown), all points 
on this vertical line are optimal foraging strategies (and NE). (c) For 
, 
and 
. Thus 
and 
. (d) For 
, 
and 
Thus 
and 
. The dashed line denotes 
(e) For 
, 
and 
. Thus 
and 
.