20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
here, though it was difficult to judge their number accurately because 
of the difficulty in penetrating the extensive mangrove swamps. 
The bird taken is typical of the resident race of Panama, being 
dark in color, with a heavy bill that measures 22.8 mm. in depth 
through the nostril. Another common name for this species is yaboa 
coronada. 
HETEROCNUS MEXICANUS (Swainson): Bare-throated Tiger Bittern, 
Jorralico 
Tigrisoma mexicanus SWAINSON, in Murray, Encyclopedia of geography, July 
1834, p. 1383. (México.) 
This curious heron, now rare in many parts of mainland Panama, 
was fairly common on Coiba where it lived in the mangrove swamps. 
Morning and evening these birds came out on the open flats or on 
areas of mud left by the receding tide, sometimes far from any 
cover. It was possible to approach them without much precaution, 
and undoubtedly it is this lack of wariness that has destroyed them 
in more settled areas, since they are easy marks for a gun, or, for 
that matter, for a well-aimed stone. They move quietly in feeding, 
often remaining motionless for long periods. Crabs seemed to be a 
principal source of their food. 
On January 21 as my cayuco, driven by an outboard motor, entered 
the mouth of the Rio San Juan, I saw four, evidently two pairs, 
engaged in a display in which they swelled out the breast and neck, 
showing a prominent orange streak down the sides. At the same time 
the bill, with the long neck fully extended, was pointed directly up- 
ward. As their legs are short they presented a most unusual, almost 
grotesque appearance. 
An adult female taken January 14 has a wing measurement of 
350 mm. 
Family THRESKIORNITHIDAE: Ibises 
EUDOCIMUS ALBUS (Linnaeus): White Ibis, Coco Blanco 
Scolopax alba LINNAEUS, Systema naturae, ed. 10, vol. 1, 1758, p. 145. (South 
Carolina.) 
Small bands frequented the extensive swamps, particularly where 
the Rio San Juan entered Bahia Damas. From here they ranged out 
to feed, as twice, at sunset, I saw a flock of a dozen flying low over 
the water of the bay past the Colonia Central bound for a roost in 
the distant mangroves. 
