1920 j Wetmore, Birds of Lake Burford., N. Mex. 407 



seeming to prefer for cover, thickets of scrub oak and clumps of Ribes 

 and Amelanchier. The birds were common on my arrival and males were 

 singing, but they may be late in nesting as a mated female collected June 9 

 was not yet ready to lay. 



76. Oberholseria chlorura (Audubon).* Green-tailed Towhee. — 

 Fairly common on the sage grown slopes above the lake. Males were 

 heard singing daily, and occasionally the birds were observed skulking 

 about in the dense growth. A nest found on June 11 was placed in a sage 

 about two feet from the ground. It was large and well-cupped in form 

 and was composed externally of grass and weedstems while the lining 

 was made of finer material. It contained three eggs whitish in color, well 

 spotted with brown and lilac. 



77. Zamelodia melanocephala (Swainson). Black-headed Gros- 

 beak. — This grosbeak was rather rare in occurrence about the lake. Males 

 were observed on June 2 and 9 in a gulch in the hills. 



78. Piranga ludoviciana (Wilson). Western Tana ger. — This Tana- 

 ger was fairly common among the Yellow Pines in the hills. The song 

 resembled that of the Scarlet Tanager but was short, slightly more broken 

 and somewhat less harsh in tone. 



79. Progne subis (Linnaeus). Purple Martin. — Migrant birds were 

 observed above the lake on June 8, 9 and 13. 



80. Petrochelidon lunifrons lunifrons (Say). Cliff Swallow. — 

 One cliff Swallow was seen with a flock of Violet-green Swallows on May 25 

 and on the morning of May 26 a flock of 25 appeared. The birds were 

 common from then on. Old nests were observed under the cliffs in several 

 localities but the birds did not begin building this year until June 9. On 

 June 11 they were building nests on the sandstone cliff above the Laguna 

 de la Puerta. The birds came down to the lake shore in little bands of 

 ten or a dozen and alighted close together with trembling wings extended 

 at an angle from their backs, standing high on their legs to avoid soiling 

 their feathers. After alighting they leaned over, filled the mouth with 

 mud with one or two sharp digs and then rose to fly back up the steep 

 slopes to the colony. Males frequently alighted on the backs of the fe- 

 males as they gathered mud and copulation took place while the birds 

 were on the ground. Males as well as females took part in nest-building, 

 as a male shot here had the mouth filled with mud held in a mass in the 

 mouth cavity above the tongue. 



81. Hirundo erythrogastra Boddaert. Barn Swallow.— A male 

 came about the cabin at the lake on June 10, examining ledges under the 

 eaves, and a pair was seen on June 14. 



82. Tachycineta thalassina lepida Mearns. Northern Violet- 

 green Swallow. — These swallows came in flocks about the cabin at the 

 lake during May and swung tirelessly back and forth in the wind, barely 

 skimming over the tops of the sage brush, in search of the many Chirono- 

 mids that had taken refuge there. Often they came beating about me ) 



*Oreospiza chlorura of the A. O. U. 'Check List.' 



