86 Cooper on the California Pygmy Owl. 



NOTES ON THE BREEDING HABITS OF THE CALIFORNIA 

 PYGMY OWL (GLAUCWIUM CAL1FORNICUM), WITH A 

 DESCRIPTION OF ITS EGGS. 



BY WILLIAM A. COOPER. 



To Mr. George H. Ready, whose untiring exertions in the oological 

 line have placed him among our most reliable collectors, I am under 

 obligations for the material for this article. 



June 8, 1876, while collecting in the bed of the San Lorenzo 

 River, two miles from Santa Cruz, Cal., he saw a male Pygmy Owl 

 with a Brown Towhee in his claws alight on one of the topmost 

 branches of a dead, isolated poplar-tree standing on the bank of the 

 river. Mr. Ready did not hear the bird call his mate, but in a mo- 

 ment she came out, took the food brought to her, and returned to 

 the nest, which was in a hole in the trunk of the tree, about seventy- 

 five feet from the ground. 



An hour's climb, which he pronounces the most difficult and 

 dangerous he ever attempted (it being quite windy at the time), 

 brought him to the nest, which was in a Woodpecker's deserted 

 burrow, about nine inches deep and two inches across the mouth. 

 The female bird was incubating on two eggs, and would not leave 

 the nest. After removing her and the eggs, together with the 

 Towhee (the head and neck of which were gone), Mr. Ready exam- 

 ined the nest. The eggs rested on a bed of twigs and a few feathers 

 forming a lining three inches deep ; in removing this he accidentally 

 broke another, an unfertilized egg, situated in the middle and com- 

 pletely covered by the twigs. The question arises, Was this nest 

 made by the Owl? Taking into consideration the facts that Owla 

 usually build no nest ; that the twigs of which the nest was 

 formed were identical with those used by Troglodytes parkmanni, 

 and that this Wren builds in similar places, sometimes as high, and 

 is a persistent builder ; that the feathers may have been placed 

 there by the Wrens, or have accumulated from birds the Owls fed 

 upon, — it seems probable that the nest was really a Wren's of which 

 the Owls had taken possession. In regard to the addled egg, the 

 Owls ami Wrens may have contested for possession ofthe nest, and 

 the egg been covered up by twigs brought by the latter : or it may 

 have been laid in a hollow formed by the twigs which the Owls 



