Vol. XXI. pp. 35-38 January 23, 1908 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



NOTES ON DIURNAL MIGRATIONS OF BATS. 

 BY ARTHUR H. HOWELL. 



Very little seems to be known about the migrations of bats, 

 either as to their extent, the manner in which they are per- 

 formed, or the species which have the migratory habit. Indeed, 

 it is only within comparatively recent years that any mention 

 of this habit among bats has appeared in literature. 



In 1888 Dr. C. Hart Merriam published a paper* under the 

 title " Do any Canadian Bats migrate? Evidence in the affirma- 

 tive," in which he showed conclusively that two species of tree- 

 dwelling bats — Lasiurus cinereus and Lasioni/cteris noctivagans — 

 inhabiting the Canadian fauna of North America, perform regu- 

 lar migrations. The evidence presented consisted in records of 

 the occurrence in winter of these species far to the southward of 

 their breeding range and the occurrence of Lasionycteris in spring 

 and fall at Mount Desert Rock, a small barren islet thirty miles 

 off the coast of Maine. The only other detailed account of bat 

 migration with which I am familiar is that given by Mr. G. S. 

 Miller, Jr., in a paper published in " Science "t wherein he de- 

 scribes the appearance and disappearance of bats at Cape Cod, 

 Massachusetts. The species noted by him were the Red Bat 

 (Lasiurus borealis), the Hoary Bat (Lasiurus cinereus), and the 

 Silver-haired Bat (Lasionycteris noctivagans), and their migrations 

 were recorded as occurring in the evening (after sunset) on nu- 

 merous dates between August 21 and September 13. The speci- 

 mens observed were flying chiefly along the face of bluffs near 

 the light-house. No evidence of a southward movement was 

 discovered, but the fact that no bat could be found on the Cape 



•Trans. Royal Soc. Canada, V, Section IV, pp. 85-87. 

 + Science (X. S.) V, Xo. 118, pp, 5-11-548, April -J. 1897. 



<>— Proc. Biol. Soc. Wash., Vol. XXI, 1908. (35) 



