158 



THE XIDIOLOGIST 



Notes on the Blue=fronted Jay. 



WHILE on a collecting trip in the 

 mountains a few miles from San Jose, 

 Cal., two years ago, I found several 

 nests of the Blue-fronted Jay. Although the 

 bird is common throughout the mountains of 

 Santa Clara, Santa Cruz, and Monterey Coun- 

 ties, wherever I have been the nests are not easily 

 found, being usually in wild, wooded canyons, 

 and retjuiring a careful search, as the birds are 

 never seen nor heard near the nest until it is 

 found. 



The first nest was near the end of a limb in a 

 live oak tree, forty feet up. Throwing a couple 

 of rocks at it, I was surprised to see a Blue- 

 fronted Jay fly from the nest, as I had supposed 

 it was a rat*-6 nest. Climbing up, I managed, 

 after much stretching, to reach the four incu- 

 bated eggs. The nest was composed of twigs 

 and Spanish moss, with an inner lining of mud, 

 and that in turn was lined with rootlets and dry 

 grass. The outside depth was six inches, in- 

 side three inches; outside diameter eight inches, 

 inside four and one half. After packing up the 

 eggs I traveled quite a distance down the gulch 

 and found two other nests in wild cherry trees, 

 not over ten feet high, containing young birds 

 that flew away as I approached. This was on 

 the roth of May. A couple of days after I 

 found three or four other nests several miles 

 from this gulch in oak, laurel, and buckeye trees, 

 in a similar location. 



On the 25th I visited this gulch again, and 

 found three eggs that I took to be a second set. 

 The nest, of the usual material, was near the 

 end of a limb in a laurel tree, twelve feet from 

 the ground, but the eggs were entirely different 

 from any other set I have taken. In all three 

 eggs about the larger ends there are short, 

 raised lines that look much like small hairs had 

 been laid on the eggs and covered with a light- 

 bluish ground color. Some of them are just 

 discernible, while others are in bold relief. 

 The spots are also different, being almost 

 blotches, whereas in the usual egg the spots are 

 generally not larger than a pin head. One is 

 spotted or blotched all over, the next has a 

 dozen spots about the larger end, while the 

 last has a weak sjjlash of dark-brown on the 

 blunt end, otherwise it is spotless. Their size 

 is normal, being 1.25X.92, 1.24X.91, 1.21X.90. 

 This year I sjjent several days in search of 

 their nests, and found but a few. 



On the 3d of May I spent the whole day 

 looking for nests, over the very ground where I 

 had taken several sets la.st year, and didn't find 

 an egg. Although the birds were there, and prob- 

 ably the nests, they were " out of sight." May 



the 7th I started out to search for their nests 

 in an unexplored portion of the county, a few 

 miles from the known nesting sites. After 

 spending four days in the search, I returned 

 home with twelve sets. Of these, six were of 

 four eggs, four of three, and two of five. These 

 are the only sets of five I have taken. I think 

 that sets of three are as common as four, and 

 some years more common. The bird is in- 

 variably found on the nest if there is a full 

 clutch of eggs, and the further they are ad- 

 vanced in incubation the closer the bird sits. 

 Have put my hand within three inches of the 

 tail before the bird would fly. On one occasion 

 I found a nest twenty feet from the ground, away 

 out on a slender laurel limb. Threw several 

 stones, but the bird didn't budge. Wishing to 

 know the reason why, I climbed the tree, went 

 out on the limb within eight feet of the nest, 

 and began shaking the limb. I finally shook so 

 hard a young bird was suddenly shaken out of 

 the nest, and after I had seen the heads of two 

 more under the old bird, I left her still sitting. 

 When scared from the nest the bird will call its 

 mate, and together they make the woods ring 

 with their scolding. They occasionally become 

 so enraged they will peck at the limb on which 

 they are standing with all the energy they are 

 capable of. In the spring the birds may be 

 found in the morning and evening along the 

 open hillsides feeding on worms and insects. 

 In the fall and winter acorns are the principal 

 food. The. nests were usually placed near the 

 ends of limbs, though a few were found placed 

 against the body of the tree, one in jjarticular 

 being in the crotch of a large oak six feet from 

 the ground. The amount of mud varies great- 

 ly in dift'erent nests, one being found with a 

 layer of mud nearly an inch in thickness. An- 

 other nest found on the nth of May had small 

 balls of earth in it the size of Hummer's eggs, 

 with but a scanty lining of rootlets. In a series 

 of these eggs now before me there is considera- 

 ble variation in shape and markings. One set 

 closely resembles those of the California^ 

 Thrasher, another is marked exactly like the 

 eggs, of the Yellow-billed Magpie, and others 

 the eggs of the California Jay. Some have 

 but few spots, principally about the larger ends, 

 while others have the ground color nearly ob- 

 scured, so thickly are they spotted. The usual 

 ground color is light-blue, which is spotted with 

 various shades of brown and not infrequently 

 with lavender and purple. One of the largest 

 sets I have taken measures as follows: 1.29X- 

 .92, 1.29X.92, and 1.18X.86; one of the smallest 

 measures 1.16X.87, n6x.86,and 1.14X.86. The 

 average of eighty eggs is 1.22X.89. 



R. H. Bfxk. 

 Berryessa, Cal. 



