October 21, 1904.] 



SCIENCE. 



539 



a day or two old. When several are together, 

 this note seems to attract them to each other, 

 ■while the ordinary call-note does not, and the 

 alarm note has the very opposite efiect. 



There is absolutely no instinctive fear of 

 man, cats, dogs, hawks or other objects, if 

 these enter quietly into the environment of 

 the birds, but a sudden shadow or unusual 

 noise causes them to utter the characteristic 

 cries of alarm (rarely), or usually to perform 

 certain acts — wholly instinctive — which have 

 for their object an escape from some supposed 

 danger. Under such conditions the terns, 

 which are not so protectively colored as the 

 skimmers, take time to run to a near-by corner 

 or shadow before squatting, while a skimmer 

 crouches instantly, and with two or three side- 

 wise flicks of feet and legs almost buries 

 himself. 



The act of pecking is instinctive to a cer- 

 tain extent, but is acquired very slowly and, at 

 first, imperfectly, in this way. By imitation 

 it is learned quickly and is performed success- 

 fully within a few minutes. 



The art of flying is wholly instinctive, all 

 the species learning the use of their wings as 

 soon as the primaries are large enough to sup- 

 port them. 



The characteristic method of feeding, which 

 has given their name to the skimmers, begins 

 to be apparent after three or four weeks, the 

 birds then taking a piece of fish from one's 

 hand with a quick run past, holding the bill 

 so low that it almost touches the ground. A 

 skimmer two months old ' skimmed ' often 

 through a small pool of water in its enclosure. 



At first the young skimmers are very weak 

 and helpless and are not able to compete with 

 terns of the same age in getting their share 

 of fish, but after about forty days they obtain 



the upper hand and soon become so aggressive 

 and domineering that they have to be sepa- 

 rated and confined with individuals of their 

 own species. 



One interesting result attained is the suc- 

 cessful establishing of a colony of laughing 

 gulls in the zoological park. These birds re- 

 quire three years to assume the adult breeding 

 plumage, and for two seasons some twenty- 

 five birds have made their home in the park, 

 without the loss of an individual. Several of 

 their number migrated south in the fall of 

 1903 and returned the following spring. Thus 

 the wonderful homing instinct of these birds 

 has been controlled and extended by bringing 

 the eggs or the very young birds to a new 

 locality, arid though the park individuals 

 doubtless mingled with others of their kind, 

 possibly even associating with their actual 

 parents, yet the Heim Liebe overcame all 

 other attractions. 



With the erection of the two new bird houses 

 now almost completed, opportunity for experi- 

 ment and observation upon the collections of 

 the society will be undertaken, on a scale of 

 elaborateness and thoroughness hitherto im- 

 possible. C. William Beebe. 



New York Zoological Sooiett. 



height measurements of the african 



PYGMIES. 



Apropos of the presence of the group of 

 African pygmies from the Wissmann Falls 

 region in the exhibit of the department of 

 anthropology at the World's Pair, it may be 

 pertinent to summarize the height measure- 

 ments given by various modern travelers who 

 have recorded their observations. Unfortu- 

 nately, the circumstances under which some of 

 these observations were made were not con- 



Observer. 



Du Challlu 



Schweinfnrth 



Wissmann and Wolff 



Stanley 



Johnston 



Belgian OflSeers 



Verner 



Verner 



Verner 



