Dry Season .5 1.5
Wet Season 3.4 4.7
But the three-times-greater-results in a given time in the dry season
do not tell the whole story as to the effectiveness of using a
beater. When an ani was hunting by itself it walked about, covering a
surprisingly large amount of ground. When using a cow as a beater, not
only did it catch more insects in a given length of time, but it also
walked about much less, saving a great deal of energy.
This is not true co-operation between cow and bird, for they're not
working together toward a common end. It's not exploitation of the cow
by the birds, for the cows lose nothing. It is closer to a form of
harmless parasitism, for the ani profits from the activities of the
cow without either harming or helping the cow. It also illustrates
how sharp birds are--ready to take advantage of any factor in their
environment that will help them get their food.