COMMON ROCK WREN 289 



of spiders, beetles, and other insects that it finds among the rocks, it 

 is surprising how many insects are to be found even in such unpromis- 

 ing places. R. C. Tate (1925) says that, in Oklahoma, its favorite 

 food seems to be "earth worms, and grubs from the bark of trees." 

 Junius Henderson (1927) states that Aughey includes the rock wren 

 among the birds that feed their young on locusts in Nebraska. Knowl- 

 ton and Harmston (1943) report that, of 74 stomachs of Utah birds 

 examined, 30 contained 59 adult grasshoppers and 1 nymph. 



Behavior. — The sprightly little rock wren adds a delightful spark 

 of life to the barren rocky landscape where he chooses to make his 

 home, a tiny bit of cheerful companionship for the lonely traveler 

 and a charming surprise in some unlikely spot. He is a busy, active 

 little body, dodging out of sight among the rocks, or perching for 

 a moment on some nearby stone to look us over, for he is not par- 

 ticularly shy. Dr. Oberholser (1921) pictures him very well as 

 follows : 



If started up from work or rest his quick, jerky flight to the nearest point 

 of observation preludes a sharp, harsh note of Interrogation and alarm, almost 

 startling in its suddenness and volume, which degenerates into a prolonged 

 sputtering scold, as the bird works himself into a ridiculous frenzy of voice and 

 of action over what he doubtless regards as a wholly unvparranted and quite 

 reprehensible intrusion. But his is an acquaintance that may well be cultivated, 

 for once we are in his confidence he is found to be more tlian ordinarily interest- 

 ing; he will sing for us, and this performance is by no means monotonous or 

 unattractive; or, confiding in our friendship, he may even lead us to the spot 

 where, protected under an overhanging ledge or hidden away in a crevice of 

 the rocks, is bis little home. His lot, with several voracious mouths to feed in 

 this all too barren land, might readily seem to be a hard one, but this is only 

 apparent, for the desert yields to the patient toil of this little worker far more 

 than falls under the gaze of the passing traveler. 



As we know so little about the roosting habits of birds, the following 

 note by R. M. Bond ( 1940) is of interest : 



The night of October 15, 1939, two Rock Wrens (Salpinctes olsoletus) were 

 found asleep in a shed near some cliffs in southern Alameda County. The 

 wrens were perched side by side on the rough, vertical side of a mud wasp 

 nest {Sceliphron, sp.) which was built on the 4 inch side of a 2 by 4 inch rafter. 

 The position of the wrens was vertical, substantially that of a perching wood- 

 pecker or creeper (Certhia), with the tails jammed against the mud wasp nest 

 for support and the feet at about mid-breast level, and far enough apart to show 

 the outer toe on each side when the bird was viewed from behind. It was not 

 possible to see exactly how the heads were held, but apparently they were 

 placed with the beak pointed downward between one wing and the body. One 

 of the birds awoke and slipped away in the beam of my flashlight, but the other 

 did not stir. I left the birds for about 15 minutes, and returned with another 

 observer. The wakeful bird had returned to its former position and posture, and 

 slipped away again. The heavy sleeper was picked up by hand. It is doubt- 

 ful if the birds could have been reached by any small mammal, because of the 

 position of the roosting site. 



