UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 793 



^^T » >v^i f^iy Contribution from the Bureau of Biological Snrvev. <: 



Contribution from the Bureau of Biological Survey, 

 E. W. NELSON, Chief. 



JTL^'^V"** 



Washington, D. C. 



PROFESSIONAL PAPER. 



July 31, 1919 



LEAD POISONING IN WATERFOWL. 



By Alesaxdee Wetmore, Assistant Biologist. 



Introduction 



History 



Species of birds affected 



Symptoms of lead poisoninj 



CONTENTS. 



Page. 

 1 

 2 

 3 

 3 



Page. 



Post-mortem appearance 5 



Results of experimental work 7 



Prevalence of shot in marsli areas 9 



Conclusions . 10 



INTRODUCTION. 



Lead poisoning in various species of "vrild ducks and other water- 

 fowl has recently attracted attention among person^ interested in 

 game birds in the United States. Though for a number of years this 

 disease has been reported in periodicals devoted to sport and from 

 other sources, it is little recognized and understood, and few sports- 

 men have any knowledge of it. Already it is causing the loss of a 

 considerable number of waterfowl each jenr, and there is no doubt 

 that as time goes on it will assume greater importance. Lead i)oison- 

 ing in waterfowl has its origin in the large quantity of expended shot 

 that from year to year is deposited in the mud about shooting points 

 and blinds in marshes, shallow bays, and lakes. Birds find and 

 swallow these leaden pellets while searching for food, and many are 

 seriously affected by the poison thus taken. Present knowledge in- 

 dicates that the mallard, canvas-back, and pintail ducks and whistling 

 swans have suffered most, but a number of other species will probably 

 be included in the list when the matter is more fully investigated. 



Many opi^ortunities have come to the writer to handle and examine 

 ducks and other birds suffering from lead poisoning during the past 

 three years, and he has had occasion to carry on experiments to ascer- 

 tain the cause and manner of the affection. The results are outlined in 



Note. — This bulletin is a report of studies made of a serious malady among' ducks and 

 other waterfowl in the United States. It is for the information of sportsmen, naturalists, 

 and others interested in game birds. 

 120366°— Bull. 793—19 



