WHITNEY'S ELF OWL 441 



another day, as we were entering the mesquite forest, between the 

 saguaro plain and the Santa Cruz River, we saw a Gila woodpecker 

 fly out of a hole, about 15 feet up in a mesquite stub; the bird, which 

 was a male, made such a fuss that we felt sure that his mate must be 

 sitting on a set of eggs in that hole. Mr. Willard climbed up, chopped 

 out the hole, and, much to our surprise, pulled out a female elf owl 

 and three of her eggs. I killed and skinned both of these birds and 

 am sure of the sexes. Whether the owl had eloped with the gay 

 woodpecker, or whether she had driven him from his newly made 

 home, or whether the woodpecker was trying to take possession of 

 the hole for his family, I will leave it to the reader to decide. 



Clyde L. Field writes to me: "I have taken eggs of Whitney's elf 

 owl on the east slope of the Santa Catalina Mountains, Ariz., at an 

 elevation of 4,800 feet, and in the Santa Rita Mountains, Ariz., at 

 6,100 feet. I took a bird from a hole in which she would likely soon 

 have laid. The nests were all in sycamore trees, there being no giant 

 cactus for miles. Mesquites were growing nearbv. Once, when I was 

 camping in a dry creek, an elf owl could be heard throughout the night. 

 The sound seemed to come from a sycamore some hundred feet away. 

 In the morning a dead stub was noticed in the tree, in which a Gila 

 woodpecker had nested for several seasons. After much hard work 

 I enlarged the hole and found the owl. It was too early for eggs, 

 also for the woodpecker. Three weeks later I returned. The wood- 

 pecker had moved up the creek. An Arizona crested flycatcher had 

 moved into the woodpecker's nest and sat on four eggs. The owl 

 was still at home and also had four eggs. I collected both sets. Ten 

 days later I again looked in on them. The flycatcher had taken the 

 owl's home and had three eggs. The owl was using the flycatcher's 

 old nest but had not laid yet. From watching three elf owls' nests, we 

 found that they lay every other day." 



Several other accounts of the nesting habits of the elf owl have been 

 published, but they do not differ materially from the accounts given 

 above. Mr. Gilman (1909) found one nesting in a woodpecker's 

 hole in a cotton wood tree. Although it may show a preference for 

 the giant cactus, it apparently will nest in any other suitable hole in 

 any kind of a tree within its habitat. 



Eggs. — Major Bendire (1892) says: "From two to five eggs are laid 

 to a set, but the most common number found is three. Of thirty-eight 

 sets taken by Mr. F. Stephens, who found the first eggs of this species, 

 twenty-four sets contained three each, twelve sets contained four, 

 and two sets five eggs. * * * The eggs of the Elf Owl are pure 

 white in color and oval in shape, the shell is finely granulated, and while 

 some specimens are rather glossy, the majority are only moderately 

 so." The measurements of 50 eggs average 26.8 by 23.2 millimeters ; the 



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