Winter
& Pacific Wren Songs: What to Listen For
1. Musicality-On
average Pacific Wren’s song is higher-pitched than Winter Wren although both songs cover the same range of frequencies (i.e. 4 to 8
kHz). Within the individual notes of Winter Wren notice that there is much less frequency change
relative to Pacific Wren where many of the individual notes span the whole range from 4 to 8 kHz.
Individual notes that change frequency faster (i.e. that are steeper on a sonagram-Pacific Wren) sound
less musical (more mechanical) than those that change frequency slower.
2. Speed of Delivery-Pacific
Wren delivers its song at a much faster rate (Sibley states more than twice as fast) than Winter Wren. Notice that this
IS NOT the length (duration) of the song (variable in both species but actually averages longer
in Pacific Wren than Winter Wren although in the example given the Winter Wren’s song is over 9
seconds in duration and the Pacific’s only somewhat over 8 seconds) BUT the number of notes per
unit time.
3. Pacific Wren has more trills closer together than
Winter Wren-Some authors state that
Pacific Wren has >50% trills in a song whereas Winter Wren has <50%. I
have not examined the validity
of this but in any event it is much harder to assess this in the field
compared with the differences in
1 and 2 above. Pacific Wren also has a much larger song repetoire (30 versus 2) but this is also difficult to assess quickly
in the field.
Both species have remarkable long songs composed of a
variety of individual notes and
trills.