Birders,

A very interesting and useful article on Alder Flycatcher songs has
appeared in the just-published issue (Spring 2004) of the Journal of
Field Ornithology. The citation is as follows:

Lovell, Scott F. and M. Ross Lein. 2004. Song variation in a
population of Alder Flycatchers. Journal of Field Ornithology
75(2):146-151.

The article does not compare songs of Alder Flycatchers from different
geographic areas, but instead is a detailed analysis of songs of 13
males
from a population west of Calgary, Alberta.

The paper makes several very interesting points, confirming a number
of observations and suspicions I had about flycatcher songs:

(1) Song development in flycatchers and other suboscine passerines is
apparently genetically programmed, and learning plays little if any
role in song development. As a result, both individual and geographic
variation in songs is far less in suboscines than in oscines (the true
songbirds).

(2) Alder Flycatcher songs contain 3 distinct notes. (Those who claim
that they contain only 2 notes either are having trouble hearing the
softer 3rd note, or are describing them inaccurately.)

(3) (Quote from article): "Our results indicate that there is little
variation in songs within individuals.... Visual examination of songs
of two marked males....also indicates that songs of individuals do not
change from year to year."

(4) Multivariate statistical analyses showed that there was enough
variation among individuals in this population that at least 91% of
the songs could be correctly assigned to the right individual (based
on measured characteristics of sonagrams). However, the paper hints,
but does not state outright, that inter-individual differences might
be difficult to pick out by the human ear. It suggests, however, that
these differences might be sufficient for the birds to identify each
other as individuals by the song.

The paper includes 8 sonagrams of 6 different individuals.

For anyone with some biological training and an interest in flycatcher
songs, I think this article should be required reading.

Wayne C. Weber
Delta, BC
contopus at telus.net