308 
REPORT OF THE CHIEF OF ENGINEERS. 
A description of tlie first plumage of this form is added from a fledgeling taken at 
Eagle Lake, California, in July. ... .. ., „ , . OTW i 
Prevailing color above, plumbeous brown ; head with bluish cast , w ngiua<I tail 
blue, as in adult; below ashy white ; feathers on throat and breast.show n ™ 
of streaks; sides of head and an imperfect bar across breast d y p 
conspicuous white line above and behind the eye. 
Pep.isoreous Bonaparte. 
r. oliscurus, Ridgw. Oregon Gray Jay, “Meat Bird.” 
This bird was not recognized as distinct from the Canada jay (P. canadensis )until quit© 
recently, when Mr. Ridgway described under the above name specimens liom bboal- 
water Bay, and indicated 'Washington Territory, Oregon, and the northwest coast 
generally'as its habitat. Mr. Ridgway, however, included the form under head of 
canadensis, presuming it to represent the Pacific coast variety ot that bird, as cajn- 
.talis does the Rocky Mountain form. ... 
A recent investigation, in connection with Mr. Ridgway. of a better series ot speci¬ 
mens than was available when obscnrus was described, leads to the belief that this toirn 
is entirely distinct from the Canada jay, its peculiarities being of a kind not explain¬ 
able upon any theory of geographical variation. As good descriptions of obscurus are 
found elsewhere, I need here merely allude to its chief distinctive points, viz . the 
conspicuous white shafts of the feathers of the back and scapulars, and the ashy 
white under parts, tending to brown only along the sides. In these particulars it dif¬ 
fers conspicuously from the others. 
During the past season obscurus was found to be a resident of the mountains from. 
Northern California to the Columbia River, its range being thus extended very materi¬ 
ally. The young in nesting plumage were taken near Camp Bidwell, California. 
My specimens from the above region agree with the types in essential respects ; in 
fact the only difference appears to be in regard to the amount of white, especially on 
forehead, it extending farther back towards the occiput than in the coast examples, 
while the general tints also are lighter. 
A comparison of specimens of the Canada jay from Alaska and Maine reveals con¬ 
siderable difference. In fact, extreme examples of the Alaska type appear to show 
peculiarities of color sufficient to warrant their separation as a variety. Even, how¬ 
ever, in the small series from the former region in the Smithsonian collection, there is 
a very noticeable amount of purely individual variation, and some specimens cannot 
be discriminated from Maine examples. So that, on the whole, I do not consider the 
difference sufficient to justify a new name.* 
That the Rocky Mountain form eapitalis intergrades completely with canadensis there 
can be no doubt, although typical specimens of eapitalis offer very tangible differences. 
In the northern Rocky Mountains, as in Montana, the peculiarities of this race very 
sensibly diminish, and the tendency towards the canadensis type is marked. From 
farther south and in its region proper, no specimens appear to be found which are not 
wholly characteristic of eapitalis. 
The following measurements express the variations in size between the forms : 
Wing. 
Tail. 
Bill. 
Tarsus. 
P. canadensis: 
Average of 6 specimens... 
5. 61 
5.93 
.75 
1.35 
Largest individual..:. 
5. 84 
6. 07 
.83 
1. 45 
Smallest individual. 
5. 33 
5.54 
.73 
1.33 
Alaska specimens, P. canadensis: 
Average of 7 specimens. 
5. 43 
5. 66 
.77 
1. 33 
Largest individual.. 
5. 67 
5. 65 
.85 
1.40 
Smallest individual... 
5. 10 
1.26 
Yar. eapitalis: 
Average of 10 specimens. 
6. 04 
5. 99 
.80 
1. 36 
Largest individual. 
6. 35 
6.12 
.82 
1. 40 
Smallest individual... 
5. 72 
5. 55 
.73 
1.34 
P. obscurus: 
Average of 7 specimens. 
5. 53 
5. 38 
.71 
1. 31 
Largest individual. 
5. 78 
5.58 
. 69 
. 321 
Smallest individual. 
5.23 
5.12 
.72 
.261 
* Since the above was written Mr. Ridgway informs me that he has given the name fuw.ifrons to 
the Alaskan coast form. 
