Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Variation in Duration and Frequency Characters in the Song of the Rufous-Collared Sparrow, Zonotrichia capensis, with Respect to Habitat, Trill Dialects and Body Size

Paul Handford and Stephen C. Lougheed
The Condor
Vol. 93, No. 3 (Aug., 1991), pp. 644-658
DOI: 10.2307/1368196
Stable URL: http://www.jstor.org/stable/1368196
Page Count: 15
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Variation in Duration and Frequency Characters in the Song of the Rufous-Collared Sparrow, Zonotrichia capensis, with Respect to Habitat, Trill Dialects and Body Size
Preview not available

Abstract

We present data on variation in frequency and duration characters of the advertising song of Zonotrichia capensis, the Rufous-collared sparrow, and information on the qualitative structure of the introductory "theme." These data are analyzed with respect to their relationships with altitude, habitat type, body size, syrinx size and the dialect variation shown by the terminal trill. Principal components analysis shows that the major axis of variation (PC1) in the frequency and duration variables is one primarily of increasing frequency and bandwidth of the trill (mainly due to increasing maximum trill frequency), increasing frequency of the theme, and of increasing song length, mainly contributed by theme length; increasing values on PC2 correspond to an increasing theme bandwidth and maximum theme frequency, with decreasing theme length and increasing trill length. PC1 scores from this analysis are negatively correlated with altitude over the whole sample. Higher-altitude habitats are usually structurally open, lower-altitude habitats usually mixed or closed. Songs from the nine categories of original, natural vegetation differ significantly in their PC1 scores, while contemporary vegetation structure has no significant effect: songs from the open-country habitats, desert, puna and grassland are shorter, have lower frequency and narrower bandwidth than all woodland, thornscrub and forest songs. With the exception of the very slow-trilled songs from the Monte desert dialect, there is a positive relationship between trill interval and PC1 score: slower-trilled songs (longer trill interval; lower trill rate) are longer, of higher frequency and broader bandwidth. The slow-trill Monte dialect songs are anomalous in having PC1 characteristics like the fastest-trilled dialect songs (puna and grassland). There is a significant negative relationship between body size and PC1, though it is nonlinear: birds from all habitats but puna are very similar in having smaller body size. Syrinx size is not correlated either with measures of body size or with habitat. It is concluded that most variation in song modal frequency and bandwidth is due to learning processes, rather than to size constraints of the body or organs.

Page Thumbnails

  • Thumbnail: Page 
644
    644
  • Thumbnail: Page 
645
    645
  • Thumbnail: Page 
646
    646
  • Thumbnail: Page 
647
    647
  • Thumbnail: Page 
648
    648
  • Thumbnail: Page 
649
    649
  • Thumbnail: Page 
650
    650
  • Thumbnail: Page 
651
    651
  • Thumbnail: Page 
652
    652
  • Thumbnail: Page 
653
    653
  • Thumbnail: Page 
654
    654
  • Thumbnail: Page 
655
    655
  • Thumbnail: Page 
656
    656
  • Thumbnail: Page 
657
    657
  • Thumbnail: Page 
658
    658