Effects of removal of tail-feathers of Allen's hummingbird on fraction of dives containing dive-sound components. See also figure 1.

Note.– There were 46 total pre-manipulation dives from 11 birds; 4 individuals underwent multiple manipulations, so data for their pre-manipulation dives are repeatedb,d. Bold numbers are statistically significant decreases (Cochran-Mantel-Haenszel test, p<0.01, bird ID as replicate).
aone post-manipulation dive contained f2, apparently due to a misidentified individual.
bcontrol data duplicated from previous row; each bird that had R5 manipulated later had R4 manipulated, after R5 had regrown.
csounds at ∼1 kHz frequency (the ghost frequency) produced in some dives.
done bird had R2 and later R3 plucked; its 9 pre-manipulation dives are included in both totals.