Fig. 8. Powers of flight versus flight angle. (A)
Ptot, PPE, Pind
and PKE. Ptot is the sum of
PPE, Pind, Ppar,
Ppro and PKE. Because of the
relatively small magnitudes of Ppar and
Ppro, they are not shown on the figure.
PPE is the same as shown in
Fig. 6B. The slope of the
regression of PKE versus flight angle did not differ from
zero (P=0.11). (B) Estimated Ptot for all
conditions, and the value of Plev+PPE
for ascending and descending conditions, with standard error bars. The broken
line indicates the value of Plev, which is the value of
Ptot for level flight without the PPE
for level flight. For every non-level flight condition,
Ptot and Plev+PPE
were similar (paired t-tests, P=0.134 for –60° and
P
0.411 for all other conditions).