BIRD NOTES AFIELD 



I noticed that whenever the birds dived the wings were 

 thrown out, seemingly to assist in swimming, instead of being 

 folded close to the body, as with most diving birds. Later ob- 

 servations confirmed the theory that they swim under water, 

 using their wings as well as their feet, for they may frequently 

 be seen from the Farallon rocks propelling themselves in this 

 manner while submerged. Indeed, the form of the wing is 

 curiously analogous to that of the penguin, being shaped some- 

 thing like a flipper, and very stiff and compact. It is, of 

 course, only an analogy, the penguin's wing being scaled, 

 while the character of the murre's wing is due to the stiffness 

 and shortness of the feathers. It seems not improbable, how- 

 ever, that the murre is gradually losing the power of flight, just 

 as the great auk lost it, in order to gain greater freedom in 

 swimming under water. Its difficulty in rising from the sur- 

 face of the wave and its habit of awkwardly falling back into 

 it would seem to argue in favor of this view, despite its swift 

 flight in a strong wind. 



In all this digression it must not be forgotten that the 

 breeze was still blowing and our little craft tumbling about as 

 it approached the bar of the Golden Gate. An occasional 

 Brandt's cormorant flapped past, its long neck stretched far 

 ahead of the clumsy, black body, as if trying its best to part 

 company with so slow a companion. When a little way out at 

 sea, we noticed, slightly isolated from the mainland, a large 

 rock completely whitened with the guano of this bird, a fact 

 indicating the presence of a large rookery. 



The wind, which had been uncomfortably brisk inside the 

 bay, left us almost entirely after we were well off the shore, 

 and we were soon rolling aimlessly on the broad ocean swells, 



[38] 



