380 BULLETIN 179, UNITED STATES NATIONAL MUSEUM 



and wild bees. Beetles made up over 11 percent of the food, 3 

 percent of which were useful species and 8 percent harmful beetles. 

 "Three stomachs, collected at the same time in Carmel Valley, are of 

 interest. They contained respectively 42, 45, and 40 percent of 

 scolytid or engraver-beetles. This was in the region of the Monterey 

 pine {Pinus radiata)^ and there is no doubt that these insects prey 

 upon those trees, and probably were taken when migrating in a 

 swarm to fresh foraging grounds. A few moths, with some uniden- 

 tified insects, make up the remainder of the animal food, a little 

 more than 1 percent." 



Behavior. — All swallows are swift and graceful in flight, but the 

 violet-green combines these attractive qualities with exquisite beauty 

 of form and color and with fearless confidence in human friendli- 

 ness. It is a pleasure to watch these dainty birds, as they sweep 

 by in loose flocks or smaller groups low over the herbage in the 

 open fields, over the surface of some small pond, or up and down 

 the bed of some canyon stream, winnowing the air for insect prey. 

 It is delightful to have one show its confidence in human nature 

 by gliding by us almost within arm's reach, showing alternately 

 its snow-white breast and the metallic colors of its back, with an 

 occasional flash of golden sheen. But they do not always course 

 low over the ground or water; on clear, warm days, when the in- 

 sects are flying high, they are often seen circling at a great height, 

 when they seem to be just white-breasted swallows. They are 

 often seen perched in long rows on the telegraph wires, like other 

 swallows, or sunning themselves in the tops of leafless trees. They 

 have endeared themselves to many bird lovers by the almost friendly 

 way they have accepted the artificial homes erected for them in our 

 towns and cities, returning each spring to greet their human friends. 



Voice. — The early-morning flight notes are referred to under court- 

 ship. Ralph Hoffmann (1927) mentions these as follows: "Before 

 dawn when the Robin chorus is in full swing, Violet-green Swallows 

 fly about in the darkness repeating over and over two or three 

 slight notes, tsip tseet fsip. Their ordinary notes are a rapid 

 twitter." 



Field marks. — The violet-green swallow might easily be mistaken 

 for a tree swallow at a distance, though its wing strokes are more 

 rapid and it sails less ; it appears to me somewhat chunkier in form, 

 though it is actually very little shorter. When reasonably near, the 

 white patches on the sides of the rump are very conspicuous from 

 either above or below. At short range, the white of the throat may 

 be seen to extend well up on the sides of the neck and over the 

 eyes, whereas in the tree swallow the eyes are entirely surrounded 

 in the black of the crown. The colors of the back may be dis- 

 tinguished only in good light. 



