59 



more insectivorous. The wood duck is almost extinct except in cap- 

 tivity. 1 It is the most beautiful of all the duck family; therefore the 

 introduction of this bird would help to perpetuate its kind, and also be of 

 use in keeping down all noxious aquatic insect life. WM. C. HERMAN, 

 Instructor in Pharmacology, Medical College of the University of 

 Cincinnati.* 



Gulls and terns that breed on islands in inland lakes are 

 effectual destroyers of many insect pests. In many parts of 

 the world gulls follow the plow and pick up grubs, wireworms, 

 etc., that are found in the upturned soil; gulls also greatly 

 assist in checking irruptions of destructive field mice and other 

 small rodents. 



Terns and some other sea birds aid fishermen by guiding them 

 to schools of food fish. The birds find schools of small sur- 

 face fish on which larger marketable fish feed, and by flocking 

 to feed on little fish the birds point out to the watching 

 fishermen the places where they must cast their nets. Both 

 seine fishermen and line fishermen watch these birds closely, 

 and often are guided largely by the actions of the gathering 

 flocks. Gulls and terns serve also to guide mariners in foggy 

 weather along dangerous coasts. These birds breed in large 

 colonies on isolated islands. Navigators of coasting craft know 

 well the locations of these islands and their position in relation 

 to the channels. In thick fog a vessel often stops at certain 

 points until the listening navigator can hear the cries of the 

 breeding birds on some well-known island. These cries, by 

 giving warning of the rocks and locating their direction, enable 

 him to correct his course. In summer fogs longshore fishermen 

 often verify their courses by watching the undeviating flight 

 of terns flying to some well-known island with food for their 

 young. 



Dr. Frank M. Chapman has shown, in an interesting paper 

 on the ornithology of the first voyage of Columbus, that we 

 possibly owe the discovery of America by Columbus to the fact 

 that he happened to approach the land at the right time and 

 place to cross the line of the autumnal flight of birds that were 

 flying from the Bermudas to the Bahamas and Antilles. The 



1 Since this was written laws protecting the wood duck have been passed, and the species has 

 increased considerably in numbers in some parts of the United States. 

 Journal of the American Medical Association, October 17, 1914, p. 1410. 



