WESTERN WOOD PEWEE 279 



Casual records. — A specimen was taken at Bermuda on April 30, 

 1852, and one was obtained at Santiago de las Vegas, Cuba, on April 

 12, 1928. One was collected at Springfield, in southeastern Colorado, 

 on May 12, 1905. 



Egg dates. — Illinois: 21 records, May 20 to July 22; 11 records, 

 June 18 to July 16, indicating the height of the season. 



Massachusetts: 31 records, June 8 to July 12; 15 records, June 15 

 to 27. 



New York : 37 records, May 22 to July 23 ; 19 records, June 15 to 20. 



South Carolina : 6 records, May 22 to June 24. 



MYIOCHANES RICHARDSONI RICHARDSONI (Swalnson) 



WESTERN WOOD PEWEE 



Plate 41 



HABITS 



A study of museum specimens would strongly suggest that richard- 

 soni should be considered a subspecies of virens, but those who are 

 familiar with the two birds in life recognize certain differences in voice 

 and nesting habits that seem to warrant the separation of the west- 

 ern bird as a full species, distinct from our eastern wood pewee. In 

 this connection the reader is referred to a discussion of the subject by 

 no less an authority than Dr. Joseph Grinnell (1928b), who says, after 

 "examination of large series of specimens," that "there is practically 

 complete intergradation by way of individual variation between rich- 

 ardsonii and virens, in structural characters. Why should differences 

 in voice or in nesting habits weigh against the use of the trinomial in 

 this case any more validly than they do in other quite similar cases 

 where the trinomial is in current undisputed employment?" 



Another keen observer, A. J. van Rossem (Dickey and van Rossem, 

 1938) seems to concur in this view, for he lists the western wood pewee 

 as Myiochanes virens richardsonii (Swainson). The western wood 

 pewee enjoys a wide distribution, as a summer resident, over the west- 

 ern half of this country, as the eastern bird does over the eastern half. 

 Whether and to what extent the two forms intergrade where their 

 ranges meet does not seem to have been satisfactorily determined. 



Samuel F. Rathbun writes to me of its haunts in Washington : "In 

 the Puget Sound region the western wood pewee can be regarded a 

 common summer resident. But, although its distribution is general, 

 for it is found alike in the cities and towns as well as the outside coun- 

 try, I have observed that it is somewhat partial to certain localities 

 and absent from others of the same general character. It shows a 

 liking for some cultivated valley through which a stream flows, or the 



