536 Bulletin American Museum of Natural History [Vol. LIII 
the habitual perching trees of the birds: these shells were not in the least 
injured, but the corneous operculum was always lacking. 
The North American subspecies of the snail-hawk, Rostrhamus 
sociabilis plumbeus Ridgway, has similar habits, as was frequently ob- 
served.! InSouthern Florida, the adult birds eat mainly Pomacea palu- 
dosa (Say) and also feed their young with the same snail. Another in- 
teresting American snail-eating bird is the northern courlan or limpkin, 
Aramus vociferus (Latham), of Florida, the Greater Antillesn, and the 
coasts of Central America. Thespecies most commonly eaten in Florida 
is Pomacea paludosa (Say). Mr. C. W. Johnson informs us that he ob- 
served a captive limpkin which was fed withthis snail. ‘““The bird,” he 
says, was very skillful in removing the animal from the shell; none of the 
shells were broken, but the opercula were missing, evidently swallowed 
with the animal. The exact method used by the bird to remove the 
animal from the shell was not observed.’? TheSouth American courlan, 
Aramus scolopaceus (Gmelin), has similar habits, as described by W. B. 
Barrows?: “They seem to feed almost exclusively on the large, fresh-water 
snail (Ampullaria) and the bills of many examined showed a perceptible 
lateral curve at the end, which I suppose is due to the constant wedging 
of the billin the apertures of these shells.” Wesuggest that this peculiar 
structure of the bill is a constant feature and probably an adaptation to 
a snail diet, like the recurved and drawn-out bill of Rostrhamus. 
We are under great obligations to Dr. J. P. Chapin for the following 
notes on the molluscan food of African birds. 
“Tt might naturally be supposed that mollusks would furnish an 
abundant food supply for the aquatic birds of Africa, yet this is far from 
being the case. ‘There seems, indeed, to be only a single species with a 
specialized diet of mollusks, namely the open-bill stork, Anastomus 
lamelligerus.* Africa has no snail-hawk, and mollusks form such a small 
‘Scott, W. E. D., 1881, Bull. Nuttall Ornith. Club, VI, p. 16. 
Bailey, H. B., 1884, The Auk, I, p. 95. 
Wayne, A. T., 1895, The Auk, XII, p. 366. : 
Nicholson, D. J. 1926. ‘Nesting habits of the everglade kite in Florida.’ The Auk, XLIII, pp. 
62 67, Pls. 11I-1v. 
*See also Pearson, T. Gilbert, 1917, ‘Birds of America,’ I, p. 201. 
81884, The Auk, I, p.277. Observations made along the Lower Uruguay River. 
“Another group of birds which specialize in eating mollusks are the oyster-catchers, genus Hzema- 
topus, family Charadriide. They are confined for the most part to the sea coasts, but the Palearctic 
Hzmatopus ostralegus ostralegus Linneus occasionally migrates to central Africa, and I collected one at 
Avakubi on October 3, 1913. Its stomach, however, contained only insects and a millipede. 
Along the coasts the oyster-catchers live very largely upon marine mollusks. Last summer in the 
Pearl Islands, off Panama, we collected three Hematopus palliatus Temminck, and Dr. Van Name gave 
me the following report on their stomach, contents: 
Stomach No. 1. 21 operculate mollusks. 
Stomach No.2. 5 large operculate mollusks. 
5 small mollusks. 
2 small crabs of family Pilumnide. 
Stomach No. 3. 1 large operculate mollusk. 
4 small mollusks. 
_ «_Lcrab, family Pilumnide. 
_Asecond species of Hematopus, H. moquini Bonaparte, probably occurs at the mouth of the Congo, 
for it isa South African bird that ranges north—so it is said—to the Gaboon. Its feeding habits are said 
to be the same as those I have indicated for H. palliatus. |J.P. Chapin.] 
