eWestern BirdsThe Quarterly Journal of Western Field Ornithologists
Vol. 46, No. 4
Western Field Ornithologists
Comparison of Vocalizations of Four U.S. Subspecies of the White-breasted Nuthatch
Edward R. Pandolfino and Nathan D. Pieplow
ABSTRACT: There are distinct regional differences among the vocalizations of the White-breasted Nuthatch (Sitta carolinensis), but only one subspecies (S. c. carolinensis) has been the subject of published vocal analyses. We used recordings made throughout the ranges of four U.S. subspecies to compare their vocalizations qualitatively and quantitatively, finding that these vocalizations may be categorized in three groups, eastern (S. c. carolinensis), interior west (S. c. nelsoni and S. c. tenuissima), and Pacific (S. c. aculeata). All four subspecies sing a simple song consisting of an evenly spaced series of overslurred notes. The rate of this song varies from <5 notes/sec to >12 notes/sec. The pitch of these songs increases from east to west, being lowest in S. c. carolinensis and highest in S. c. aculeata. Sitta c. aculeata also has an additional song unique to that taxon consisting of a series of sharply slurred, evenly spaced notes that fall, then rise, and then fall in pitch. Both S. c. carolinensis and S. c. aculeata frequently give a simple call note that is very distinctly and rapidly modulated; it is significantly higher in pitch in S. c. aculeata than in S. c. carolinensis. Neither interior subspecies makes a similar call. Both interior subspecies commonly give two calls absent from the repertoires of S. c. carolinensis and S. c. aculeata, one consisting of tightly paired notes given at a constant pace, the other a very rapid, unevenly spaced series of single notes given in short bursts. We found no diagnostic differences between the two interior subspecies in either song or calls.