412 BULLETIN 2 03, UNITED STATES NATIONAL MUSEUM 



ivy, bayberry, Virginia creeper, and sumac. It is often seen feeding 

 on the ground probably on grass and weed seeds. Its food habits 

 seem to be wholly b-eneficial. 



Behavior. — The pine warbler is normally quite deliberate in its 

 movements, as it creeps in a leisurely manner over the trunks and 

 larger branches of the pines, searching for insect eggs or larvae in 

 the crevices in the bark. It clings to or climbs over the trunks as 

 easily as a brown creeper, and explores the bases of the needle clusters 

 or hangs from them in the manner of a titmouse. It is quite lively at 

 times, as it flies from the top of one tree to another, sometimes for a 

 long distance, or as it darts out into the air after a passing insect. 

 It frequently feeds on the ground, picking up seeds, grubs or insects; 

 Eidgway (1889) says that "when on the ground it progresses by a 

 graceful gliding walk, much after the manner of the Red-poll War- 

 bler {D. falmavum) .'''' If disturbed while feeding on the ground, it 

 flies up and clings to the trunk of the nearest tree ; but it is usually 

 rather tame and approachable. On its breeding grounds it is almost 

 constantly in song, flying about from tree to tree, and where it is 

 common, the voices of several may be heard in various directions. 

 E. E. Stewart (1943) writes: 



In late August and September, following the breeding season, these birds show 

 a drastic change in habits and frequently occur in small flocks around the head- 

 quarters buildings. Here they generally may be found associating with Blue- 

 birds {Sialia sialis) and Chipping Sparrows (Spizella passerina) , feeding on the 

 ground as well as in the bushes and trees of the orchards and landscaped areas. 

 While watching these mixed floclis it was noticed that the Pine Warblers were 

 extremely quarrelsome, frequently fighting among themselves, as well as giving 

 chase to Bluebirds, Chipping Sparrows and, on one occasion, a Vesper Sparrow 

 {Pooecetes gramineus). 



Voice. — Aretas A. Saunders contributes the following study : "The 

 song of the pine warbler is a short trill or series of rapid notes. It is 

 not loud but is quite musical and pleasing in quality. The notes are 

 rarely all on one pitch but vary up or down a half tone. The number 

 of notes, in those songs in which the separate notes are distinct, varies 

 from 8 to 27, averaging 13. A few songs are made up of a single 

 trill, that is, the separate notes so rapid that they cannot be counted. 



"Of my 17 records of this song, only 2 are all on one pitch, the re- 

 mainder showing variation. This slight variation in pitch is one of 

 the characters of this song that distinguishes it from chipping spar- 

 rows, juncos, or other species that sing a simple trill. The pitch in 

 my records varies from A"' to E"", a range of three and a half 

 tones. Single songs rarely vary more than a tone and a half. Songs 

 vary in length from 1 to 2% seconds. 



"I have noted no difference that is definite between the songs of 

 migrating birds and of those on breeding grounds, I have no definite 



