1 66 



ZOOLOGICAL SOCIETY BULLETIN 



SKIMMER, 14 DAYS OLD. 



LEAST TERN, SI DAYS OLD. 



NOTES ON HATCHING AND REARING 

 SEA-BIRDS. 



By C. WILLIAM BEEBE, 



CURATOR OF BIRDS. 



Illuslralioiis from photographs by /he author. 



IN July of last year when we returned from our 

 trip to Cobb Island {vide Annual Report of 

 the Zoological Society for 1903, pp. r6i to 

 181) we brought with us some two dozen eggs of 

 various sea-birds. These were from the nests of 

 black skimmers, common terns, laughing gulls, 

 clapper rails and green herons, only one egg be- 

 ing taken from each nest, and all in advanced 

 stages of incubation. At first no special care was 

 taken of the eggs, as the embryos were intended for 

 embryological study, and three days elapsed be- 

 tween the time of collecting them and the date of 

 their examination. They were brought to New York 

 in an empty kodak case, and several were cracked 

 or partly broken on the way. The temperature 

 during this time ranged from 60° to 80°. These 

 apparently unfavorable conditions were sufficient 

 to keep the embryos in a living active state. Their 

 vigor was so pronounced that the eggs were placed 

 at once in an incubator, in a temperature of 102°, 

 with the result that almost all, even the cracked 

 ones, hatched within from one to five days. 



I devoted what time I could spare to feeding 

 and watching the first quintet of these little fellows, 

 hatched so far from their home among the Vir- 

 ginia sand dunes, and a few hasty notes taken 

 during the first two weeks of their existence seem 

 worthy of record. These five birds were: Two 

 common terns (Sterna hirundo)^ a black skimmer 

 {Rynchops nigra), a laughing gull {Lariis atriciUa), 



and a green heron (Biilorides virescens). For 

 convenience of observation, all the birds were con- 

 fined together in a large wooden box, glass-fronted, 

 wire-roofed and with a flooring of fine, white sand. 



July 23. — Tern number one hatched at 6 a.m. 



July 24. — Tern number two and a skimmer 

 emerged at 6 a.m. All the birds which hatched 

 from this lot of eggs broke shell early in the morn- 

 ing except the green herons, which appeared to be 

 governed by no time rule. 



This morning I removed tern number one from 

 the incubator, and fed him a number of times with 

 macerated fi.sh, the little fellow readily opening 

 his mouth for food. 



While yet wholly within the egg terns utter a 

 peep! peep, much like a chicken, but the instant 

 they tumble out, before their feathers have begun 

 to dry, they utter the typical tear-r-r of the old 

 birds, only, of course, very fine and weak in tone. 

 When calling for food their utterance is an oft- 

 repeated, indescribable sound which may be per- 

 fectly imitated by drawing air in between one's 

 teeth. The tear-r-r is always given when the 

 young birds are suddenly awakened from sleep. 



July 25. — A little green heron hatched to-day, 

 pot-bellied, with immense yellow feet and legs — 

 as unlike the terns as can be imagined. 



The second tern and skimmer were placed in 

 the sand box. Tern number one has weak thighs, 

 his legs sprawling out sideways, refusing to sup- 



