The Carlisle Mosquito Online

Friday, December 16, 2005


Pine Warbler Dendroica pinus

On December 3, my wife D'Ann saw a warbler on our sunflower heart feeder. I had seen the bird, but assumed it was an American Goldfinch; they love sunflower hearts. The warbler returned the next day with many goldfinches, and we identified it as a Pine Warbler. When seen next to a goldfinch, the warbler is larger, with a longer bill. The warbler's tail is longer and narrower, and only the outermost tail feathers are white above. The goldfinch has a smaller head, but probably a bigger stomach. The Hilton Pond Center for Piedmont Natural History (South Carolina) website (1) has excellent photos of the two birds, and compares differences in appearance.

This is our late-season record for Pine Warblers in Carlisle. Birders would say that a Pine Warbler is a "good bird" at this time of year, since most have migrated. According to Ken Harte's records for the annual Christmas Bird Count (CBC), there was a previous record of Pine Warblers in 1986, and also on last year's count day, reported by Leslie Thomas. Winter reports of Pine Warblers are more common in southeastern Massachusetts. Almost the entire Pine Warbler population winters in the southern United States (2).

Pine Warblers breed in Carlisle, and in the spring and early summer you might hear its warbling trill in areas with stands of pine. Its genus name Dendroica derives from a Greek word meaning "tree-dweller" and the species name derives from the Latin word pinus, for pine (3). In the breeding season we often hear males singing in our yard, where there are large white pines. We have never seen a nest, but we have seen females collecting nest material, in late April and early May, at the Cranberry Bog and Towle Land. According to Harrison (4), the nest is almost always in a pine, built well away from the trunk on a limb, usually 30-50 feet above ground. The nest is well hidden by clusters of needles and is difficult to see from the ground.

Warblers eat mostly insects, but during the winter they will eat seeds, fruit, and suet. A birder in Hardwick, Mass. recently reported (on Massbird listserve) seeing a Pine Warbler at a feeder eating suet, thistle (nyger) seed, and millet. Last year's CBC Pine Warbler visited the Hartes' suet feeder the week after the count; our bird, however, seems uninterested in suet. We're hoping our warbler stays for the CBC, but keeping the sunflower heart feeder filled until the day of the count (January 2) will be expensive!

The writer is grateful to Ken Harte for providing CBC data.


1. Hilton Pond Center for Piedmont Natural History

2. K. Kaufman, Lives of North American Birds, Houghton Mifflin, 1996, pp. 534-5.

3. E. S. Gruson, Words for Birds, Quadrangle Books, 1972, p. 241.

4. H. H. Harrison, Birds' Nests, Peterson Field Guides, Houghton Mifflin Co., 1975, p. 194.

2005 The Carlisle Mosquito