50 
THE CONDOR 
Vol. XV 
of birds were feeding extensively upon grass- 
hoppers. Taking into account numbers of 
individuals as well as destructive capacity of 
each species, the relative importance of the 
five ablest destroyers was as follows: (1) Bi- 
colored Blackbird, (2) Western Meadowlark, 
(3) Killdeer, (4) Bullock Oriole, and (5) 
California Shrike. 
It is shown that with abnormal increase of 
such an insect as the grasshopper, many birds 
appropriate this food source for the time be- 
ing, and at once factor in checking the out- 
break. The principle is emphasized that birds 
turn to the sort of food most readily avail- 
able. While figures are given which show 
conclusively that the birds of the region could 
not have controlled the plague after once 
well under way, the author reasons by infer- 
ence that many incipient insect outbreaks may 
be checked by birds at the outset, so that they 
never reach a point where great damage re- 
sults. In the Los Banos outbreak, the insects 
had become so abundant locally that the birds 
when under observation made no noticeable 
headway against the pests from day to day; 
but it was possible to figure the value of the 
birds in hastening the end of the insect raid, 
and even in lessening the amount of aggre- 
gate damage sustained at the time. 
Mr. Bryant’s paper is commendable in its 
accurate detail of fact. More particularly is 
it admirable in the calm and judicious mode 
of drawing inductions. There is no discord- 
ant note of sentimentality to mar the paper 
as a scientific contribution. — J. Grinnelp. 
A Revision of the Forms of the Great 
Blue Heron (Ardea herodias Linnaeus). 
By Harry C. ObErholser (Proc. U. S. Nat. 
Mus., vol. 43, December 12, 1912, pp. 531-559). 
In this treatment of the Great Blue Heron 
ten geographical races are recognized, four 
of them being first described here. Descrip- 
tions, critical comments, and other details of 
the work are presented with all the painstak- 
ing care and accuracy characterizing previous 
contributions of the author, whose series of 
studies of various difficult groups forms such 
a valuable portion of the ornithological litera- 
ture of recent years. 
The paper under consideration is of espe- 
cial interest to California ornithologists, in 
that two of the new subspecies described are 
from this state. Ardea herodias hypcronca, 
type locality Baird, California, is the name 
applied to the form inhabiting California in 
general, excepting the southeastern desert re- 
gion and the Santa Barbara Islands. Hyper- 
onca is distinguished from the Eastern A. h. 
herodias by its greater size alone, being ex- 
actly similar in color ; as the much paler col- 
ored tregansai occupies the desert and Great 
Basin regions intervening between the habi- 
tats of hyperonca and herodias, it is quite 
logical to recognize in nomenclature the dif- 
ferences between the two latter forms. 
As much cannot be said of the island sub- 
species described. The characterization of 
Ardea herodias oligista is based upon a single 
immature bird from San Clemente Island, 
and such sweeping generalizations are made 
trom the weak basis afforded by this one 
specimen that it almost appears that the au- 
thor is giving expression to a preconceived 
belief that there should be a separate island 
subspecies, rather than to a dispassionate ex- 
position of what his material actually reveals. 
The only difference claimed for the island 
race is its smaller size. Coloration is de- 
clared to be the same as in the mainland form 
hyperonca. The one specimen available, 
though admittedly an immature bird, is said 
to be “evidently full grown”. From the date 
of capture, August 26, this may, perhaps, be 
questioned. At any rate it is unfortunate that 
the only character ascribed to the race is one 
that might be explained by the immaturity of 
the single specimen examined. The subspe- 
cies described upon the strength of this one 
young bird from San Clemente Island is giv- 
en a range including “Santa Cruz, San Nico- 
las, Anacapa, Santa Catalina, and probably 
other islands of the group”, although certain 
of these islands have as little in common with 
one another as they have with the mainland. 
We are also told that “this race is prob- 
ably confined to the Santa Barbara Islands, 
as the species is said to be resident there”. 
Just what grounds there are for the latter 
assertion is not apparent, and it is doubtful if 
the statement could be proved. The islands 
are such a short distance from the mainland 
that the intervening channels can be but in- 
considerable barriers to a strong flying bird 
like the Great Blue Heron. In the present 
paper (page 536) we are told of a specimen 
of A. h, herodias taken at sea about 130 miles 
off the coast of New Jersey! Furthermore, 
a favorite feeding ground of the herons about 
the islands is on the extensive beds of float- 
ing kelp, which support the birds easily, and 
form convenient resting places at short in- 
tervals, should any such be required. 
Altogether, even conceding the possibility 
of the existence of a race of Ardea herodias 
confined to the Santa Barbara Islands, we 
cannot admit it to be proved, nor even demon- 
strated to be reasonably probable, in the 
paper under discussion, while there are many 
facts that argue against it. 
The description of the subspecies oligista 
seems ill considered, and is an undoubted 
blemish in what appears to be in other re- 
spects an excellent piece of work. It would 
