10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I43 



Scolopacidae. — Likewise, the sandpipers, as they run up and down 

 the beach or fly swiftly to new hunting grounds, use a fairly large 

 flight apparatus (flight muscles, 23 to 32 percent and hearts, I to 

 1.54 percent) and small to moderate lower extremities (4.5 to 

 9 percent). 



Recurvirostridae. — The birds in this group are similar to the 

 other shore birds, being equipped for strong flight. 



Laridae. — The flight apparatus of gulls and terns differs in con- 

 formity with their respective habits. The slow-flying gulls, which soar 

 much, possess rather small hearts (0.85 percent), moderate flight 

 muscles, and moderate lower extremities (5 to 6 percent), while the 

 more active terns, which dash about and dive for fish, have larger 

 hearts (0.84 to 1.08 percent), flight muscles about the same, and 

 lower extremities only half the size of those in gulls. 



Rynchopidae. — Skimmers are almost identical with terns with 

 respect to their equipment; they are swift and dextrous as they plow 

 the surface of the water for food. 



Columbidae. — Doves and pigeons can be divided into two groups 

 according to heart size. In one group hearts range from 0.28 to 

 0.56 percent of the body; in the other, from 0.93 to 1.29 percent. 

 Those of the first group are Leptotila cassini, Leptotila rujinucha, 

 Geotrygon costaricensis and Geotrygon chiriquensis, while all other 

 species including Leptotila verreauxi, are in the second group. We 

 are unable to explain the differences between the two species of the 

 genus Leptotila. The contrast in muscle values between Leptotila 

 cassini and Leptotila verreauxi, both collected at sea level, is striking. 

 The heart of verreauxi is larger (P<o.oi), while the pectoral muscles 

 of cassini are larger (P<o.oi ) . The heart of Columbigallina passerini 

 of Florida is larger than that of Columbigallina talpacoti (P<o.05) 

 of Panama; the heart of Claravis pretiosa is larger (P<o.oi) than 

 that of Claravis mondetoura. The flight muscles of all pigeons are 

 almost as large in proportion (31 to 44 percent) as those in tinamous, 

 and the supracoracoideus is as large or nearly as large as the "rest" 

 group. The wings are quite large (buoyancy ratio, 3.0 to 3.65), the 

 legs small to moderate (4.5 to 7.8 percent). Both the wild and 

 domesticated species of Columba are powerful long-range fliers, while 

 Columbigallina flies but short distances. 



Psittacidae. — Parrots are usually strong fliers and make good use 

 of their legs. The female Brotogeris is larger than the male. All have 

 fairly large hearts (1.03 to 1.52 percent) and large flight muscles 

 (25 to 28 percent). The supracoracoideus is one-third to one-half 



