BREWSTER: BIRDS OF THE CAPE REGION, LOWER CALIFORNIA. 141 
Ammodramus rostratus sanctorum (Ripew.). 
San Benito SPARROW. 
Passerculus sanctorum Ripeway, Proc. U.S. Nat. Mus., V. 1883, 588 (San Benito I.). 
P [asserculus] sanctorum RipGway, Loc. cit., 538, 539 (crit.). 
Ammodramus (Passerculus) sanctorum Couns, Auk, XIV, 1897, $2, 93 (crit.). 
Ammodramus sanctorum McGrecGor, Osprey, Il. 1897, 42 (deser. habits, nest and 
eggs from San Benito Islands); Auk, XV. 1898, 264, 265 (descr. female, 
juvenal plumage). 
Among the Passerculi collected by Mr. Frazar in or near the Cape Region 
are six specimens which, although variously intermediate in size between 
A. rostratus and A. r. guttatus, are colored more nearly like the latter. On 
comparing them with eleven examples (including the type) of A. r. sanctorum 
from the San Benito Islands, which Mr. Ridgway has been kind enough to 
send me for examination, I find that five belong, without question, to that 
recently separated — or rather resuscitated — insular race. The sixth bird is 
smaller than any of the others, and, indeed, not larger than one or two of the 
largest representatives of halophilus from Point Abreojos, but in respect to 
coloring it appears to agree more closely with sanctorwm, to which, not t without 
hesitation, I have finally decided to refer it. 
This subspecies, originally named by the late Dr. Coues upwards of twenty- 
five years ago, but not until some time afterwards formally recognized either 
by him or by other ornithologists, is represented, as I have just said, by several 
skins in Mr, Frazar’s collection, obtained at Carmen Island on March 6, and at 
San José del Cabo between October 10 and November 9. Mr. Ridgway has 
also mentioned three specimens “resembling ‘ P. sanctorum’ in coloration” 
which were collected by Mr. Belding at La Paz in January and February. 
From this we may infer that the bird is of regular and not very uncommon 
occurrence, in or near the Cape Region, in autumn, winter, and early spring. 
It is believed to be confined to Lower California at all seasons, and its only 
known breeding grounds are on the San Benito Islands. These islands, three 
in number, are described by Mr. R. C. McGregor as “situated about twenty 
miles west of Cerros Island. The two largest have each an area of several 
square miles and are from 200 to 400 feet high. The islands are quite dry 
during the summer season. For nine months almost no rain falls, while the 
porous and rocky character of the soil precludes the existence of springs or 
the formation of marshes and pools. The flora is semi-desert in nature. 
Several species of cacti and some small insular plants make up the vegetation, 
there being nothing which attains the size of a shrub or tree. Both the large 
islands are very hilly and these have been cut up by the heavy winter rains. 
The gullies so formed are often difficult or impossible to cross. It will thus 
be seen that the home of Ammodramus sanctorwm is essentially different from 
that of any of the salt marsh Ammodrami.” 
