Vol. XXVIII 

 1911 



Ewing, English Sparrow and Bird Mites. ooO 



THE ENGLISH SPARROW AS AN AGENT IN THE DIS- 

 SEMINATION OF CHICKEN AND BIRD MITES. 



by h. e. ewing. 

 Observations. 



During the summer of 1905, while the author was engaged in 

 making collections of various external parasites near Areola, 111., 

 a large hay-barn was found in which a multitude of English Spar- 

 rows had nested. From the roof of the barn there extended up- 

 ward a large cupola, the inside of which soon proved to be perfectly 

 alive with sparrows. Numerous nestlings were found, either 

 concealed in the some score of large, trashy nest-bundles, so 

 characteristic of the species, and which occupied the various 

 recesses and corners of the wooden structure, or, being now almost 

 full-fledged, had fluttered out of the nests whence their ill spent 

 attempts at flight had caused no small amount of concern on part 

 of the parents. However, as is not usually the case, the sparrows 

 evidently did not have complete possession of this veritable 

 hatching house for their species for a few pigeons had also 

 shared with them the use of this structure, and an examination 

 revealed some three or four nests of these. Luckily for us collectors 

 the cupola was provided with a trap door, so after entering the 

 structure we were enabled to capture several of the live birds and 

 examine them for parasites. None of these birds were killed, but 

 a perfectly enormous number of parasites were secured, and among 

 them was found a very great number of what seemed to be the 

 common poultry louse, or chicken mite, Dermani/ssus gallinoe Redi. 

 Later studies have fully established the correctness of this offhand 

 determination. 



Since the sparrow has been recognized for some time as being 

 one of the many hosts of an allied species (Dermani/ssus avium 

 DeGeer), for a long while I was inclined to doubt that this mite 

 was the real mite of poultry, yet the near proximity of the hay- 

 barn to a chicken-house, which at least for some years had been 

 known to be infested with the chicken mite, strongly suggested to 



