BIOLOGY

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FIELDIANA ZOOLOGY

Published by
CHICAGO NATURAL HISTORY MUSEUM

Volume 34 APRIL 18, 1955 No. 31

A NEW SPECIES OF THRUSH FROM ANGOLA

AUSTIN L. RAND

CURATOR, DIVISION OF BIRDS

In the first shipment of birds from Angola, from the collection
made in 1954 by Gerd Heinrich for Chicago Natural History Museum,
were three specimens of a thrush that is so obviously a new species
that it is described here in advance of the study of the rest of the
collection.

Cossypha heinrichi sp. nov.

Type. Chicago Natural History Museum no. 221,000. Duque
de Braganza (about 30 km. northeast), northern Angola. Adult,
sex(?). Collected May 30, 1954, by Gerd Heinrich.

Diagnosis. A large-sized member of the genus Cossypha ap-
proaching albicapilla in size, and with a long graduated tail like
that species but at once distinguished from all the other members of
the genus by the coloration: the whole head and neck are pure
white; the breast, abdomen and under tail coverts, outer tail feath-
ers, and rump are rich dark orange rufous; the back is dark grayish
olive; and the central tail feathers are black.

Description. Adult, sex(?) [= female]; head and neck all around
pure white; back grayish olive, some of the feathers with faint dark
tips that give a lightly scaled appearance; rump and upper tail
coverts, and under parts from breast to under tail coverts and thighs
deep orange rufous, darkest on breast; lesser upper wing coverts
like back; greater wing coverts similar, but grayer; primary coverts
blackish, lightly washed with grayish olive on outer webs; primaries
and secondaries blackish, and, except for the outmost, narrowly
edged with grayish olive and the inner secondaries washed with olive;
central tail feathers black; next two black on inner web and chest-
nut on shaft, outer web, and tips of inner web; next three pairs of
rectrices chestnut, about like rump; outer pair damaged, but one of
the pair all chestnut like the others, the other broken, but appar-

No. 746 327

THE UB-^RY Of THE

Ntf.

JUL 8 1955

328 FIELDIANA: ZOOLOGY, VOLUME 34

ently with a black margin to outer web for distal half. Under wing
coverts grayish black, tipped with chestnut; rest of under wing
unpatterned grayish black.

First year plumage: Sex(?) [=male?]; similar to the adult but
the greater wing coverts and many of the lesser ones with chestnut
tips; a few blackish tips to some rump feathers; the next to the cen-
tral pair of rectrices chestnut with only a narrow edging of blackish
on inner web; and the distal half of the outer web of the outer pair
of rectrices blackish. In addition, the rectrices are narrower and
more pointed.

Nestling plumage, male (reconstructed from a bird molting into
first year plumage) : Head, neck, and breast buffy ochraceous, the
feathers with blackish margins that give a scaled appearance; back
similar but more ochraceous and with wider black margins; abdo-
men buffy ochraceous.

Details of external structure: Bill very similar in detail of shape,
subterminal notch, position, shape and feathering of nostrils to
albicapilla and heuglini and about half way between the more slen-
der, shorter bill of heuglini and the longer, stouter bill of albicapilla;
rictal bristles small and inconspicuous as in albicapilla; tail long,
slightly longer than wing, and strongly graduated as in albicapilla,
the outer tail feathers about two-thirds as long as the central ones;
wing rounded, with first (outermost) primary somewhat longer than
one-half of second ; wing tip formed by tips of fourth, fifth, and sixth
primaries, which are subequal; tarsus booted and slender.

MEASUREMENTS

First
Adult 9? year d"? Juv. d"

Wing 115 119 114

Tail 128 132

Culmen (from base) 21 24 23

Tarsus 37 40 39

(damaged)

Range. Known only from the type locality near Duque de
Braganza in northern Angola.

Remarks. Mr. Heinrich sent three specimens of this striking
new species, all from the one locality. On the back of one of the
labels is the note, "Savannah with scattered bushes and small trees."
The specimens were taken in April and May; the well-grown imma-
ture still bearing much nestling plumage but molting into the white-
headed adult plumage, was taken April 3, and the other immature

3 /

RAND: THRUSH FROM ANGOLA 329

in plumage very similar to that of the adult on April 8. This indi-
cates that the breeding season was past.

In large size and in long, graduated tail this species seems closest
to C. albicapilla of the savanna belt of Upper Guinea and as far south
and east as Cameroon and French Equatorial Africa. However, it
lacks the elongated feathers of the nape of albicapilla, has a pro-
portionately longer tail, and a more slender tarsus. The rufous
plumage is very much darker, and the mantle is olive, instead of
black. The color pattern of the all white head and neck seems unique
in the genus and the orange rufous coloration is much darker and
richer than in any other species. It seems advisable to consider it a
species, near albicapilla.

'*

UNIVERSITY OF ILLINOIS-URBANA