152 Dr. R. W. Slmfeldt on 



observe this Swift in its favourite haunts ; for all through 

 north-western New Mexico occur deep, even-walled canons 

 of rock, to which Micropus melanoleucus resorts to rear its 

 young. 



Early in the spring of 1885 (April) I found some two 

 dozen pairs of them in just such a canon about three miles 

 west of Fort Wingate. The walls of this magnificent gorge 

 are of solid rock, being nearly 350 feet deep in some places, 

 and for the most part roughly perpendicular, though fre- 

 quently arching over and outwards at their summits. It 

 was within the deep and crack-like fissures seen in the walls 

 of the eaves of these latter recesses, away high up on either 

 side of this rocky chasm, that Micropus resorted to lay its 

 eggs. So wisely had every pair of these birds chosen the 

 cleft wherein their nests were hidden, that all my plans and 

 attempts to secure a set of eggs proved futile'; and Professor 

 Coues tells us that they " do not appear to have been taken 

 yet, but are presumed to be white, as in all the species the 

 eggs of which are known " ^. 



However, I find Dr. Heermann, the ornithologist who 

 accompanied one of our early surveys, expressing himself in 

 the following words upon the nidification of the " White- 

 bellied Swift '' in his report. He says : — " I met this bird 

 several times, first in San Fernando Pass, near ' Los Angeles,'' 

 again near Palm Spring, between Colorado desert and Valle- 

 cita ; again near Tucson, and, lastly, in Texas, always, 

 however, flying at a great height, being either far beyond 

 or on the extreme limit of gun-shot range, and was there- 

 fore unable to do more than slightly wound one of them. 



" From the extent of their wings, the birds of this family 

 appear to be formed to live in the air, where, in fact, they 

 pass most of their time, gliding about in extensive circles, 

 without effort, and apparently little motion of the wings. 



''This ease of flight stands them in good need in their 

 migratory movements, allowing them readily to pass into 

 warmer climes. During pleasant weather they find their 



* E. Coues, ' Key to North American Birds,' 2nd ed. (Boston, 1884), 

 p. 456. 



