42 Vol. IX 



MIGRATION AND NESTING OF THE SAGE THRASHER 



BY M. FRENCH OILMAN 



THIS bird, Oroscoptes mowtanus, was a favorite of mine from boyhood, tho I 

 saw little of him, merely a passing acquaintance, as it were. He seemed to 

 attend strictly to his own business, that of migrating, but was never nervous 

 or flurried. He apparently never had time for frivolities or any side trips, tho I 

 can't say that he hurried on his way. He would run to a bush, halt an instant, 

 and then on to another. If bushes were far apart he would sometimes fly from one 

 cover to another, halt, and then forward again. A worm in the interval, did not 

 turn him aside; he would swallow it and move on. He knew just where he was 

 going, and while in no haste to arrive, was not to be diverted from the straight and 

 narrow path. He seemed to be aware that a straight line was the shortest di.stance 

 l^etween two points, and even if pursued could not be forced many points off his 

 course. 



These were my earlier impressions of his character and caused much interest 

 and some observation of his migrating. These few notes on the travels of the sage 

 thrasher were made in southern California and include territory about thirty- 

 five miles long and three or four wide, San Gorgonio Pass, extending from Palm 

 Springs on the Colorado desert, 500 feet elevation, to the summit of the Pass, 2500 

 feet elevation. 



At Palm Springs the thrashers usually appeared about the middle of Januar3\ 

 tho I have seen them there during the latter part of December. They came in 

 from a southeasterly direction, across the desert, moving from bush to bush as I have 

 described. Their rate of travel seems very slow in view of the fact that they 

 always appear to be moving forward. Some seasons they would be a month in 

 traversing the thirty or thirty-five miles, a speed of about a mile per day. I am 

 satisfied that this is their average speed across the country I have mentioned, as I 

 have observed it on short distances as well. I have seen the birds at all points be- 

 tween the two localities named, and the dates of observance practically coincide 

 with the estimated speed of travel. I have noticed the birds five or six miles east 

 of town and a week later they would appear a mile or two west of town. I walked 

 a mile and a half to school, to the east of my home, and would see the first birds in 

 the morning at the school end of the line. On m_v way home in the evening I 

 would overtake them about a mile from where I had seen them earlier in the day. 



Now I do not pretend to give these figures as an estimate of their rate of travel 

 during the entire migration. To do so would be absurd, as their destination is so 

 far from where I observed them. At a mile per day they could never reach their 

 nesting place, raise a famil^^ and get back to winter quarters. I do not know the 

 nearest point where their nests may be found; but from some experience in their 

 nesting haunts in southwestern Colorado, I believe some parts of the Mojave Desert 

 would be promising. 



In forming any theory of migration so much data is necessary that I hesitate. 

 Any one, however, has some right to an opinion, and mine is that the sage thrasher 

 migration is local rather than general. I have never seen them on their return 

 trips in the autumn and some seasons they have failed to materialize in the spring 

 movement. I saw them in their nesting places in Colorado as late as October 30, 

 and judging from movements of some of our California birds in perpendicular mi- 

 grations, these thrashers would not go to the Mexican line to spend the winter. 



