THE HOARY BAT 223 



The discovery by Dr C. Hart Merriam ' that the Hoary 

 Bat annually performs a migration ^ no less extensive than that 

 of many birds seems to put a very different complexion 

 upon the matter, and makes Wolley's record one of the most 

 interesting ever contributed to British mammalogy. This bat 

 is known to breed only in the boreal zones of North America,^ 

 but in winter it occurs at least as far south as the most 

 southern border of the United States. It has been taken on 

 the Bermudas, showing that it is able to cross a strip of ocean 

 having" at its narrowest extent a width of over 600 statute 

 miles, that is between the Islands and Cape Hatteras, which 

 lies very little north of due west of the Bermudas. It is, 

 however, much more likely that the bats commence their oceanic 

 passage at some point much further to the north, such as 

 Cape Cod, the distance from which to the Bermudas is 

 about 700 statute miles. They certainly pass Cape Cod on 

 migration, since Mr Gerrit S. Miller, jun.,'' found them 

 there on passage in the autumns of 1890 and 1891, in 

 the former year from 26th August to 2nd September, in 

 the latter from 25th August to 12th September. The 

 distance from Cape Cod to the Orkneys is about six times 

 that to the Bermudas, but if a bat started its flight 

 from Nova Scotia or Newfoundland, the distance might 

 be reduced, in the latter case to four and a half times. It 

 seems, therefore, to enter the bounds of possibility that a 

 creature which habitually passes over 600 or 700 miles of 

 ocean should occasionally be blown the whole way across the 

 Atlantic, especially if its passage happened to coincide with 

 some great hurricane. The season at which Wolley's bat was 

 found at South Ronaldshay corresponds with that of the 

 autumnal migration of its kind past Cape Cod, and it would 

 almost seem that the species deserves to be included in the 

 same category as the various American birds which from 

 time to time strike our coasts. But the case of a bat is 



1 Trans. Royal Soc. (Canada), 1887, iv., 85-87. 



2 Some observations of A. H. Howell {Proc. Biol. Soc, Washington, xxi., 35-38, 23rd 

 Jan. 1908) suggest that, when migrating, bats may fly at high elevations, and by day ; 

 but further information is needed, and our knowledge of the subject is still very slight. 



^ Miller, North American Fauna, No. 13, 112, 1897. 

 * .Science, New Series, v., 542-543, April 2, 1897. 



