186
J.W. Boughman and C.F. Moss
A)
B)
C)
i.
ii.
iii.
iii.
iii.
ii.
ii.
i.
i.
Time (sec)
0
0.5
1.0
1.5
2.0
2.5
0
0
0
4.0
2.0
4.0
2.0
4.0
2.0
1.25
0.75
0.25
–0.25
–0.75
–1.25
–1.75
–2.25
dimension 2
dimension 1
–2
–1
0
1
2
A)
B)
Sound amplitude (mV) and frequency (kHz)
Figure 4.9. Yellow-naped amazon parrot contact calls from three dialects. (A)
Sonograms and waveforms of contact calls from two birds at three roosts (i–iii) in
the (a) northern, (b) southern, and (c) Nicaraguan dialects. (B) Multidimensional
scaling of spectrogram cross correlations with calls from 16 roosts. Each point represents an individual coded by roost: northern (open symbols), southern (closed
symbols), Nicaraguan (heavy-lined open squares), border roosts (cross and plus
symbols). Minimum-area polygons enclose birds classified from each of the three
dialects. (From Wright 1996. Reprinted with permission from The Royal Society.)
J.W. Boughman and C.F. Moss
A)
B)
C)
i.
ii.
iii.
iii.
iii.
ii.
ii.
i.
i.
Time (sec)
0
0.5
1.0
1.5
2.0
2.5
0
0
0
4.0
2.0
4.0
2.0
4.0
2.0
1.25
0.75
0.25
–0.25
–0.75
–1.25
–1.75
–2.25
dimension 2
dimension 1
–2
–1
0
1
2
A)
B)
Sound amplitude (mV) and frequency (kHz)
Figure 4.9. Yellow-naped amazon parrot contact calls from three dialects. (A)
Sonograms and waveforms of contact calls from two birds at three roosts (i–iii) in
the (a) northern, (b) southern, and (c) Nicaraguan dialects. (B) Multidimensional
scaling of spectrogram cross correlations with calls from 16 roosts. Each point represents an individual coded by roost: northern (open symbols), southern (closed
symbols), Nicaraguan (heavy-lined open squares), border roosts (cross and plus
symbols). Minimum-area polygons enclose birds classified from each of the three
dialects. (From Wright 1996. Reprinted with permission from The Royal Society.)