106 THE ZOOLOGIST. 



Lesser Grebe, P.Jiuviatilis, Tunst. — A rare occasional visitor, 

 only seen on the Tyne. A pair, one of which I saw in the flesh, 

 were shot by a loafer at Smithy Burn on Jan. 14, 1878. It is 

 odd that this bird has not been observed more frequently, since 

 Mr. Hancock, in his Catalogue of Northumberland birds, includes 

 it as a resident. 



AMERICAN ORNITHOLOGISTS' UNION. 



BIRD MIGRATION. 



At the first congress of the American Ornithologists' Union, 

 held in New York City, September 26th to 28th, 1883, a Com- 

 mittee was appointed to investigate in all its bearings, and to the 

 fullest extent possible, the subject of the migration of birds in 

 the United States and British North America. The work will 

 not be limited to the accumulation of records of the times of 

 arrival and departure of the different species, but will embrace 

 the collection of all data that may aid in determining the causes 

 which influence the progress of migration from season to season. 

 For example, severe storms, gales of wind, protracted periods of 

 unusually high or low temperature (for the locality and time of 

 year) are among the atmospheric conditions that are known to 

 exert marked effects upon the movements of birds. The opening 

 of the leaves and the flowering of certain plants, with the cor- 

 relative appearance of a multitude of insects, are also among 

 the actors that have to do with the abundance of many species. 

 Hence the careful registration of certain meteorological phe- 

 nomena, and of the state of advancing vegetation from day to 

 day, will constitute prominent items in the record-books of the 

 observer. 



For the purpose of rendering the result of the season's work 

 as full and valuable as possible, the Committee earnestly solicits 

 the co-operation of every ornithologist, field-collector, sportsman, 

 and observer of nature in North America. 



For convenience in collecting and arranging the enormous 

 mass of material which will be accumulated by the joint labours 

 of this army of field workers, it has been deemed advisable to 

 divide the vast expanse of territory embraced in the United 



