29o Correspondence. [ July 



CORRESPONDENCE. 



{Correspondents are requested to urUe briefly and to the point. No attentionwil 



be paid to anonymous communications. 



The Delaware Valley Ornithological Club. 



To the Editors of the Auk : — 



Dear Sirs: — The majority of the readers of 'The Auk' have no doubt 

 spent a good deal of time in the study of bird migration and in the syste- 

 matic arrangement of their field notes with a view to reaching general 

 facts in regard to the subject. While a single observer making careful 

 notes for a number of years can determine many interesting facts, such as 

 the average time of arrival and departure of the various birds at his 

 station, and the relation of the 'migration waves' to meteorological varia- 

 tions ; still there are many other points bearing on the subject of migra- 

 tion which it will be impossible to study without the assistance of other 

 workers in the same field. 



Recognizing the advantages to be gained by combined work, a number 

 of ornithologists residing in the vicinity of Philadelphia have organized 

 he Delaware Valley Ornithological Club, for the study of the birds of 

 southeastern Pennsylvania and southern New Jersey, with especial refer- 

 ence to their migration in the valley of the Delaware River. The active 

 membership of the club is limited and consists only of those who have 

 had considerable experience in field work and are known to be thor 

 oughly reliable. An associate membership has been added to include 

 beginners in the study who can furnish data subject to the approval of the 

 active members, and in return can receive the benefit of their experience. 



The following is a brief outline of the methods, of work of the Club t 

 Daily field notes are taken by the members, and recorded systematically on 

 monthly charts containing vertical columns for the days and horizontal 

 ones for the birds in the order of their occurrence during the month. The 

 spaces are sufficiently large for recording the number of birds seen (as 

 recommended by Mr. Batchelder, in the April number of 'The Auk'), and 

 short abbreviated notes as to singing, mating, nesting, etc. Across the 

 top of the chart are blanks for recording the curve of temperature varia- 

 tion, the direction and force of the wind, and other corellative notes. In 

 addition to these individual charts there are "combined monthly charts," 

 on which the notes of all the observers are recorded followed by private 

 marks indicating their various stations. These charts are passed from one 

 member to another and when all the data have been recorded are repro- 

 duced by a copying process and copies furnished to each observer. In the 

 same way it is proposed to have yearly charts on which will be recorded 

 the first and last occurrence, arrival and departure of bulk, and other gen- 

 eral facts relating to each species. 



The Club meets in Philadelphia twice a month, when all matters of 

 importance are discussed and specimens exhibited. 



Another aim of the Club is to keep a complete record of all the birds 

 which occur in southeastern Pennsylvania and southern New Jersey, and 



