134 BULLETIN 203, UNITED STATES NATIONAL MUSEUM 



The chestnut upper tail coverts can be seen only when the bird is in 

 certain positions. Its activity will mark it as a wood warbler, and it is 

 the only one of this family likely to be found on its breeding grounds 

 among the mesquites in the nesting season. 



Enemies. — Mr. Howard (1899) says that "many nests are destroyed 

 by wood-rats and snakes." And Mr. Dawson ( 1923) writes : 



Dwarf Cowbirds are prominent in the formidable host of enemies which this 

 tiny bird must face. Sometimes the warblers are able to entrench themselves 

 behind apertures so narrow that the Cowbird cannot get in; and once we saw 

 the Cowbird's foundling resting unharmed, but also harmless, upon the "door- 

 step," not less than two inches distant from the warbler's eggs. Another nest, 

 more exposed, contained three eggs of the arch enemy, and had been deserted 

 by the troubled owners. The Gila Woodpecker is an especially persistent 

 enemy. Accustomed as he is to polling and prying, he seems to take a fiendish 

 delight in discovering and devouring as many Lucy Warblers' eggs as possible. 

 We caught several of these villains red-handed, and we found reason to believe 

 that more than half of the nests in a certain section had been wrecked by them. 

 Add to these the depredations of lizards, snakes, and, possibly, rats, and the 

 wonder is that these tiny gray waifs are able to reproduce at all. 



DISTRIBUTION 



Range. — Southwestern United States to central Mexico. 



Breeding range. — Lucy's warbler breeds north to southern Utah 

 (Beaverdam Wash, Zion National Park ; Calf Creek, Garfield County ; 

 and the San Juan Kiver) ; and southwestern Colorado (Montezuma 

 County near Four Corners) . East to Colorado (near Four Corners) ; 

 western New Mexico (Shiprock, possibly San Antonio, mouth of 

 Mogollon Creek, and Bedrock) ; southeastern Arizona (Bisbee) ; and 

 northeastern Sonora (Moctezuma). South to northern Sonora (Moc- 

 tezuma and Saric) ; southern Arizona (Baboquivari Mountains, Men- 

 ager's Dam, and Gadsden) ; and southern California (Picacho and 

 Silsbee). West to southern California (Silsbee, Mecca possibly, and 

 Chemehuevis Valley) ; western Arizona (Fort Mojave) ; and south- 

 western Utah (Beaverdam Wash). 



Winter range. — ^The few available records place the winter home 

 of Lucy's warbler in central western Mexico from Jalisco (Bolailos 

 and Lake Chapala) to eastern Guerrero (Iguala). 



Migration. — Few migration dates are available for a species with 

 such a limited range. Early dates of arrival are : Arizona — Tucson, 

 March 12. California — Mecca, March 29. Utah— St. George, March 

 23. A late departure date is : Arizona — Tombstone, October 3. 



Egg dates. — Arizona : 58 records, April 22 to June 27 ; 30 records, 

 May 2 to 21, indicating the height of the season. 



