1 68 



ZOOLOGICAL SOCIETY BULLETIN 



Sprawler's name is now meaningless, as he is 

 rapid!}' learning the use of his legs as supports, 

 instead of sand-oars, thanks to the surgical thread. 



When the shadow of my hand passes over them 

 the terns and skimmer crouch as closely as possible 

 to the sand, but when I speak to them they rush 

 toward my approaching hand, which they have 

 already learned means food. At a temperature of 

 110° in the direct rays of the sun, they pant vio- 

 lently. At 75° they shiver; and 90° in the shade 

 seems to satisfy them best. 



When eager for food the terns gape widely, 

 straight upward, and flutter their wings vigorously. 

 The heron pecks forward, or often downward, 

 while the skimmer, when excited by the touch 

 and smell of a bit of fish, pecks very ineffectively, 

 turning his head to the right and then reaching 

 straight ahead. I still have to force his bill open 

 to get the pieces of soft tish far enough down for 

 him to swallow them. 



At 12 A.M. to-day .Skimmer's bill measures gh 

 mm. in height across the nostrils, while Samson's 

 mandibles are only 5 mm. at the same point. 



At 2 P.M., after sleeping most of the morning. 

 Heron waked up and showed remarkable energy. 

 From his elevated vantage point in the small stick 

 basket he surveyed the terns and even followed 

 them as they walked about the edge of the twigs, 

 ambling on his tarsi (his toes being not yet un 

 curled) and pecking at their heads. 



There is a decided difference in color between 

 the terns and the skimmer. The terns are light 

 yellowish above, with tufts of black scattered on 

 the back and wings. The chin and upper throat, 

 and the face below the eyes are black. The re- 

 mainder of the under parts is fluffy white. The 

 feet and legs are reddish, the bill is light with 

 the terminal fourth black. Skimmer is of a much 

 lighter hue above — a light sandy gray — with less 

 conspicuous black spots. There is no black about 

 the head, and the under parts are white. The legs, 

 and especially the feet, are darker in color, being 

 more brownish. The bill is partly red, partly 

 brown. 



July 29. — When feeding time comes, Samson 

 jumps frantically u]) and down, and Heron rolls 

 his eyes and climbs toward his spoonful by means 

 of feet, wings and bill. Skimmer grows but little, 

 and still has to be fed by force. 



July 30. — None of the young birds seemed to 

 relish their food to-day, so a new diet was prepared. 

 Heretofore the fish (tiny killie-fish) was half boiled, 

 chopped and mi.xed with ants' eggs. Now a hearty 



meal was given to the ever ravenous wood ibises, 

 and two hours later a little judicious teasing per- 

 suaded them to disgorge a mass of finely commin- 

 uted fish, sweet-smelling and, I hoped, adapted to 

 the digestion of the little terns. I was right, as it 

 proved, for at one feeding they ate more than they 

 had during the entire dav. 



When frightened the terns now run to the dark- 

 est corner, but Skimmer gives several side flicks 

 with his feet, making thus in an instant a little 

 cavity into which he sinks, drops his head close to 

 the sand and — disappears, his back almost flush 

 with the general level of the sand. It is a mar- 

 velous bit of instinctive jugglery. 



July 31. — Sprawler — who sprawls no more — 

 and Gull fight lustily over bits of fish. 



The reason why Skimmer so persistently refuses 

 to accept food is because in his bill — as in that of 

 the adult bird — the sensitive area is confined to 



COMMON TERN, 7 D.WS (ILD. 



the base. The food must be put on or back of 

 the tiny tongue to e.xcite the nerves of swallowing. 



Sprawler and Gull now pick up things, and once 

 the former chased a cockroach about. Gull 

 learned to peck by watching Sprawler. The 

 latter picked up a bit of fish, Gull snatched it from 

 him, dropped it, and when Sprawler made another 

 rush at it. Gull picked it u]) for himself — his first 

 attem])t. 



Aug. 2. — All the birds are doing finely on wood- 

 ibis — pre-digested fish. 



Four least terns, three weeks old, were placed in 

 the box. These birds had been weaned to whole 

 fish — very small ones, of course. I offered one 

 about an inch long to Sprawler, who fairly leaped 



