ECOLOGY OF ISLE ROYALE. 417 



North America. The typical form however, ranges from Labrador and 

 the Arctic Sea, westward to the north shore of Lake Superior, Ontario, 

 to the Eocky Mountains, Michigan, northern Pennsylvania and New 

 York. In spite of its activity, four other forms have become more or 

 less differentiated but their ranges are not well defined, laoustris oc- 

 curs west of Hudson Bay, energumenus from Pacific Coast from British 

 Columbia to Alaska, ingens from the Yukon Valley and vulvivagus 

 from the Gulf States. 



11. Putorius cicognani Bonap. Bonaparte's or Least Weasel. Only 

 one specimen was secured, and this is a white skin taken by Michael 

 Hollinger in the vicinity of the Club House, at the head of Washington 

 Harbor, on December 31, 1904. (No. 33016). 



Dr. Merriam ('96, p. 6) has called attention to the close correlation 

 between the geographic range of the cicognani group of weasels and 

 the field mice (Microtus) , but upon Isle Boyale these mice are appar- 

 ently lacking; it is probable therefore that the White-footed mice form 

 an impertant element in their food. 



Ecological Notes. — ^Very little seems to be known of the breeding 

 habits of this species. It is reported (Cones, '97, p. 109) to have three 

 litters of young a year, with four or more, frequently five, in a litter. 

 The nest, located in a depression in the ground or a hollow tree, is com- 

 posed of dry vegetation. The female shows almost unlimited courage 

 in the defense of her young. The food consists of small mammals, birds 

 and eggs, and insects. As to its native habitat preferences, in the Adiron- 

 dacks Merriam ('86, p. 54) says: "It inhabits all parts of the wilder- 

 ness, being found along water-courses, in deep swamps, and on rocky 

 ledges and mountain sides." Like the Mink, it tracks its prey by scent. 



The seasonal color changes of this weasel are of special interest. 

 Ehoads speaking of Pennsylvania weasels ('03, p. 172) says "Bona- 

 parte's weasel always turns white in winter even in its most southern 

 distribution, but the New York weasel [P. novchoraccnsis] in the tran- 

 sition and austral zones very rarely turns white, the winter pelage be- 

 ing merely paler than that of summer." 



Geographic Range. — The typical form ranges over forested areas 

 of Labrador; New England; New York; Pennsylvania, in the moun- 

 tains; Ontario; Northern Michigan; Minnesota; Colorado; British Co- 

 lumbia and Southeastern Alaska.. In 1896, ISIerriam said : "It probably 

 occurs also in northern Michigan and Wisconsin." Merriam ('96, p. 

 12) recognizes two varieties: richardsoni ranging from British Colum- 

 bia and the interior of Alaska to Hudson Bay, and alascensis from 

 southern Alaska. 



12. Putorius novel)oraGensis De Kay. New York Weasel or Ermine. 

 Two specimens were secured; one a small pale brown skin and skull 

 (No. 33015) on December 31, 1904, by Michael Hollinger, near the head 

 of Washington Harbor, and the other a, much larger white skin taken 

 in January, 1905, (No. 33019). Both of these specimens are referred 

 to this species with doubt by Dr. Merriam. 



Ecological Notes. — The breeding season occurs in February or March, 

 and the young are born in April and May. The number of young in a 

 brood appears to vary greatly, from two to a dozen, although four to 

 six is perhaps the average number (Coues, '77, p. 125, 134). In the 



