Comments on the Contents of a Grebe's Crop 1 



By Howard H. Cleaves 



On Wednesday, November 4, there was brought to me a 

 horned grebe Colymbus auritus, which had been shot at Princes 

 Bay, Staten Island, on the same date. 



I skinned the bird, and through curiosity opened its crop to 

 determine its contents. Of shrimps there were several. I found 

 also the somewhat mangled remains of a number of "spuring" 

 or silversides. I then found what seems to be the body of a 

 young mossbunker, which was pretty well preserved. Most in- 

 teresting of all was a rather large red rubber band. These were 

 distributed through a mass of more thoroughly digested food. 

 There were many very small, white pebbles, which evidently aided 

 in the process of digestion. 



A large part of the mass mentioned above consisted of what 

 I finally made out to be feathers. There must have been many 

 of them. Mr. James Chapin tells me that he has ascertained 

 from Mr. Waldron De Witt Miller, of the American Museum 

 of Natural History, that it is a regular habit with the horned 

 grebe to pluck feathers from its own body and swallow them. He 

 could, however, give no explanation of the purpose of the grebe 

 in doing so. 



Mr. Chapin suggested that the grebe probably mistook the red 

 rubber band for a sandworm when it was swallowed, and that 

 is the most likely explanation, although I did not find the slightest 

 remains of any true worms. It would seem they should have 

 been discovered if they form a part of the grebe's regular diet. 



1 Read at the meeting of the Section of Biology, November 14, 1908. 



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