Mar., x9ot [ THE CONDOR 33 Some Architectural Traits of the Western (ioatcatcher (Polioibtila c?erulea ohscora.) BY CORYDON (?HAMBERLIN, VALLECITo? CALIF. V?ith sketches from nature by the author. HE few observations on t%lioptila c. obscura here recorded cannot do justice to this very interesting sub- ject and are offered only in lieu of a more complete study. Of all the birds it has been my lot to make unhappy, I cannot think of any one whose good qualities have appealed to me more strongly than the Western Gnatcatcher. He is the embodiment of many good characteristics; whenever seen he is a delight to the eye and his note, if not musical, is unique and unmistakable and you may be sure of him whenever you hear it. On his arrival in this latitude, near the first of April, he adds new life to the woods and his lease, tease-e may be heard incessantly on every hand. When he first appears in his trim "tailor-made" suit of black, white and gray he seems at once the very personification of dandyism and well-bred modesty, but no one can accuse him of vanity for he forgets his appearance entirely in the pursuit of work as he is a model of in- dustry. Mr. (;natcatcher is thoroughly domes- tic in his nature and usually establishes two homes each breeding season. How many fake nests he builds or how many of his pretty houses are robbed or torn up by his enemies I cannot tell. It is as an ai'chitect principally that I wish to dwell on the gnatcatcher and will re- turn to this part of the subject further on. The name ?natcatcher is ntisleading as regards the diet of this species, for I have repeatedly seen one tackle a butterfly almost as large as himself and bag his game, too. I think however his food is largely made up of the eggs and larvae of insects which are found on the under-side of leaves and in the crevices of bark. I have also seen him feed on small flying insects which may have been gnats or mosquitoes. The bluejay is strongly in evidence as an enemy of the gnatcatcher and loves to tear .the half-finished nest from its foundation and sit in the top of the tree with it sticking out on the sides of his bill like bunches of gray whiskers. The gnatcatchers usually resent such intrusion, and worry the jay until he drops the nest or flies away with a harsh mocking cry. I have known a pair of gnatcatchers to chase a jay from tree to tree until he was a safe distance from their nest when they would suddenly disappear to be found half an hour later in their own tree resting and scolding softly. An unaccountable habit which this species has is that of congregating in flocks and flying from tree to tree with much noise and fluttering.. I cannot imagine anything but a free-for-all cake walk that can be compared to this gre- garious movement. I have often thought at such times that they were driving bluejays away for I have always seen jays flying about noiselessly on such occasions but I cannot with certainty give the cause of such assemblages, for they usually broke up when I ap- proached the center of disturbance. It may however have been merely a choir practice or some social function,-who knows? During the spring of'95 I first became acquainted with the Western Gnat- catcher near Lakeport, Lake Co., this state. In the latter part of April I ob- served them building their nests. All of the first nests I found were in small white oak trees from six to ten feet from the ground. Of the first few nests I saw being built none were finally oc- cupied on their original site. One pair near my camping place moved their nest and made it over three times before being satisfied to deposit eggs in it. Each time that the nest was nearly complete, the birds would discover a