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LIBRARY OF THE
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39
»~52
-73 FIELDIANA - ZOOLOGY
Published by
CHICAGO NATURAL HISTORY MUSEUM
Volume 39 SEPTEMBER 18, 1961 No. 52

A New Race of Crow, Corvus enca,
from the Philippines

AUSTIN L. RAND
CHIEF CURATOR, DEPARTMENT OF ZOOLOGY
AND

Dioscoro S. RABOR
ASSOCIATE, DEPARTMENT OF ZOOLOGY

In the course of Dr. Rabor’s field work in northeastern Luzon,
in 1960, he collected two specimens of the crow, Corvus enca, which
provide a substantial range extension of the species, and, as he rec-
ognized, represent an undescribed subspecies. For this we propose
the name:

Corvus enca sierramadrensis, new subspecies

Type.—Chicago Natural History Museum No. 260,006, from
San Pascua, Gonzaga, Cagayan Province, in Sierra Madre, Luzon.
Adult female, collected April 20, 1960, by D. S. Rabor.

Diagnosis.—Most like C. e. samarensis, from Samar, but bill
shorter and more slender, culmen less arched; concealed bases of
feathers of neck and forepart of body grayer; plumage generally
more intensely black.

Range.—Known only from Cagayan Province of extreme north-
eastern Luzon.

Remarks.—The discovery of this species on Luzon has some zo0o-
geographical implications. Hitherto, its supposed absence there has
suggested that some historical factor might have been responsible
for its not reaching Luzon. Now that we know that it occurs in the
three largest main islands of the Eastern Philippine Province (Luzon-
Samar—Mindanao), as well as the Mindoro District and the Palawan
group (small and large islands), it would seem that the distribution

pattern and the great variations in abundance in the Philippines
Library of Congress Catalog Card Number: 61-17859 a. ~

No. 927 577 HIDD rR ~

OV 24 196
Por eidia SITY OF ILL

578 FIELDIANA: ZOOLOGY, VOLUME 39

(Luzon, scarce and local; Samar, common; Mindanao, rare and local;
Mindoro, rare; Palawan, common) may be due to ecological factors.

The three Philippine races, judging by present material, are fairly
distinct as follows:

(a) C. e. pusillus Tweeddale.—Palawan (type locality), Balabac,
Calamianes, Mindoro. Plumage with a grayish sheen, especially on
under parts; feathers of foreback, breast, and neck with white bases;
bill long but slender; wing, tail, and tarsus long.

Meinertzhagen (1926, Nov. Zool., 33: 72) listed Mindoro birds
as “subsp.,”’ saying that they were glossier than pusillus, especially
on crown and forehead. While there may be a difference, in that the
Mindoro birds are very slightly darker and glossier, and on measure-
ments the Mindoro birds have a slightly heavier bill than do Pala-
wan birds, these characters are not nearly evident enough to keep
them separate, judging by present material.

(b) C. e. samarensis Steere.—Samar (type locality) and Minda-
nao. Like pusillus, but plumage more intensely black above and
below, and with a purplish blue gloss, especially on upper parts;
feathers of neck with concealed bases grayish white; bill long but
deeper and with culmen more arched; wing, tail, and tarsus shorter.

Dorst (1947, L’Oiseau et Rev. Francaise d’Orn., 17, (n.s.), p. 74),
who separated violaceus of Ceram (with the Philippine birds puszllus
and samarensis as subspecies), as a different species from enca, con-
sidered Mindoro birds as referable to samarensis. Our material lends
little support to this allocation (see above). We have seen no Min-
danao specimens, but we assume that they are samarensis, as usually
considered.

(c) C. e. sierramadrensis Rand and Rabor.—Extreme northeastern
Luzon (see above for characters). This race shows an intensification
of the plumage characters which separate samarensis from pusillus,
and it is as small or even slightly smaller than samarensis on wing,
tail, and tarsus measurements, again separating it more widely from
pusillus, but the bill is slender as in pusillus and is shorter than in
either of the other two races.

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