MIGRATION DATA ON CITY HALL TOWER. 



BY WILLIAM L. BAILY. 



(Read before the Seventeenth Congress American Ornithologist's Union, Philadel- 

 phia, November 14th, 1899.) 



In the centre of the city of Philadelphia, five hundred feet and more 

 above the pavement, on top of the City Hall Tower, stands the colossal 

 bronze figure of William Penn, encircled with a ring of arc lights which 

 burn the night long. Unintentionally this beautiful circle, crowning the 

 highest point for miles around, has been the destroyer of many birds 

 during their nocturnal migrations between their winter and summer 

 homes. As much as we deplore this unfortunate destruction, we have 

 been able at the same time to obtain some interesting data upon the 

 subject of migration. 



In 1897, August 28th, there appeared in thePhiladelphia Evening Bul- 

 letin an account of a rare bird that was found on the balcony just below 

 the lights of the tower. The discovery of a dead bird at such a great 

 height was a curiosity indeed to the keeper of the tower and his assist- 

 ants, and its correct identity even puzzled the mind of the learned re- 

 porter, who pronounced it a rare specimen ; but why it had chosen this 

 lofty spot to breathe its last was a mystery to all who were called into 

 consulation. My attention was attracted to the article, and upon in- 

 vestigation, I found the bird to be a young Sora Rail. This was the first 

 bird that had flown against the tower since the lamps had been lighted, 

 on July 4th of the same year. I immediately took steps to interest Mr. 

 Slaughter, the superintendent of the electrical department, and from 

 that day to this, records have been kept of all birds that have been 

 found, the species being noted and the sex when possible, as well as 

 the conditions of the weather. More than a hundred specimens have 

 been saved, about seventy of which Mr. Slaughter has had mounted and 

 perched in a glass case made for the purpose. Each morning during 

 the migrating periods, the tower, roofs and court below have been 

 scoured and the specimens submitted to me for identification. Fifty- 

 six species have been found, and at least one of each has been mounted 

 or the skin saved. In all, five hundred and twenty-nine specimens have 



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