TACHYCINETA THALASSINA, YIOLET-GREEN SWALLOW. 87 



Hah. — Middle and Western Provinces. North to British America. South throu^'h 

 Mexico to Guatemala. ° 



List of specimens. 



19208 

 19210 

 19211 

 19350 

 19351 



31 

 15 

 14 



Wind River.. . 



do 



do 



G. Bull Creek. 

 do 



$ 



May 26, 18G0 



do 



do 



June 7, 1860 

 June 5, 1860 



F. V. Haydeu. 



do 



do 



G. H. Trook.. 

 do 



Not obtained by Lieutenant Warren's Expedition. 

 Later Ejpedilions. — 61665, Utah. 



A fine series of this lovely Swallow was procured by Captain Ray- 

 nolds, and its eggs are also in tbe collection. The locality is apparently 

 at about the northeast limit of distribution of the species. It does not 

 appear to be recorded north of Washington Territory and Vancouver. 

 In winter it retires beyond the United States, reaching to Guatemala. 

 Its breeding range appears to comprise all suitable localities in that por- 

 tion of the (Jnited States it occupies, as well as parts of Mexico ; to the 

 southward, it chiefly occupies elevated and wooded situations. 1 found 

 it abundant in the Raton IMountains of New Mexico, in June ; it was 

 then doubtless breeding. In Arizona, as I have already recorded [l. c), 

 it is very abundant, being the characteristic Swallow of the, pine regions, 

 ■where it breeds ; it arrives at Fort Whipple about the liOth of March, 

 and remains until late in September. Dr. Cooper noticed its arrival in 

 the Santa Clara Valley, California, as early as March 15th, and further 

 observes that it ''frequents chiefly the groves of oaks along the sides of 

 the valleys and across the whole coast range, excepting the windy and 

 cold neighborhood of the sea. They range at least as far north as the 

 Straits of Fuca, and across the interior to the eastern base of the Rocky 

 Mountains." Dr. Suckley report.s its arrival at Paget Sound about the 

 10th of May. Mr. Allen found it in July and August, in Colorado, in 

 the Ganlen of the Gods, about Castle Rock, and at Lake Pass. 



A well known and often recorded point in the economy of the Swal- 

 lows, is the readiness with which they modify their ways of nesting ac- 

 cording to circumstances. Those species, like the Barn Swallow, the 

 Wliite-bellied and Cliff Swallows, and the Purple Martin, which inhabit 

 populous countries, have almost completely changed their modes of nid- 

 itication, now breeding in the convenient places aflbrded by buildings, 

 or in .shelters expressly provided for tlieir use. In the case of the Cliff 

 Swallows, the change is of very recent date, and many records are pre- 

 served of the precise time when, in particular localities, the birds de- 

 serted cliffs to build under eaves, or when, adopting tliis habit, they 

 appeared and bred in places where they were before unknown. With 

 the Purple Martins the modification occurred earlier, and I am not aware 

 that the time is recorded. But in the west both these birds still adhere 

 to their primitive Avay.s. Along the ^Missouri I saw great numbers of 

 nests of Cliff Swallows stuck in batches on the high vertical water- 

 worn exposures; and in Arizona the Martins occupied the blasted tops 

 of tall ])iiie-trees, in colonies, having driven olf the Woodpeckers, right- 

 ful i)roi»rietors of the holes that riddled the trunks. It becomes an 

 interesting specula'iion whether the Bank Swallow will ever abandon its 

 burrows, ami so far modify its fossorial nature as to build in chinks and 

 crannies, or aihx a nest anywhere about a building. As far as is now 

 known, the \'iolet-green Swallow retains its primitive habits, but the 

 same easy adaptal)ility to varying circumstances may be observed in 

 this case, warranting the inference that before long it will accept the con- 



