SMALLER MAMMALS OF NORTH AMERICA 



491 



numbers run in cycles of about seven years 

 each. 



As the hares increase in numbers some of 

 the birds and mammals which prey upon them 

 increase proportionately. This is specially 

 marked with the big northern lynxes. The 

 skins of varying hares are gathered and sent 

 to the London fur market with other furs, in- 

 cluding those of lynxes. In the records of 

 sales of the Hudson's Bay Company there are 

 direct increases of the numbers of Canada 

 lynx skins sold corresponding with the in- 

 creases in the sales of varying hare skins. As 

 the number of hare skins abruptly decreases 

 following the outbreak of epidemics among 

 them, there are correspondingly abrupt de- 

 creases in the numbers of lynx skins sold. 



This correlation is shown in the records ex- 

 tending back many years and illustrates the 

 interdependence in nature between the vari- 

 ous forms of animal life. The far-reaching 

 tragic effect of the sudden disappearance of 

 the snowshoe rabbits is not confined to the 

 wild habitants of the forest, as it has not_ in- 

 frequently brought starvation and death into 

 many lonely Indian lodges in the great north- 

 ern wilderness. 



THE ARCTIC HARE (Lepus arcticus and 



its relatives) 



{Por illustration, see page $io) 



Many parts of the northernmost circumpolar 

 lands are occupied by large hares, which attain 

 a weight of more than ten pounds. They are 

 about the size of large jack rabbits, but are 

 more heavily proportioned, with much shorter 

 ears and shorter, stronger legs. There are sev- 

 eral species and geographic races of these ani- 

 mals, all of which are snowy white in winter 

 except for a small black tip on each ear. In 

 summer the southern arctic hares change to 

 a nearly uniform dull iron gray or grayish 

 brown. The northernmost animals of Elles- 

 mere Land and north Greenland, where the 

 summer is brief and severe arctic conditions 

 prevail, retain their white coat throughout the 

 year. 



In keeping with the cold climate of their ter- 

 ritory, the furry coat of the arctic hares is 

 long and thick, especially in winter, when the 

 ears, legs, and even the soles of *^he feet, as 

 well as the body, are heavily furred. The 

 coats of the hares of north Greenland and ad- 

 jacent region are so heavy and fleecelike that 

 during the spring molt they come off in felted 

 patches as the new coat is assumed, giving the 

 hares a curiously ragged appearance. 



In the region between the areas in which the 

 summer coat remains wholly white and where 

 it is completely changed to grayish, there is a 

 gradual transition, with the lessening severity 

 of the climate, through every intermediate de- 

 gree between the two. As in the case of the 

 snowshoe rabbit, the large hind feet and long 

 spreading toes of its big northern relative are 

 so heavily covered with hair that they form 

 broad fluffy pads, which enable the hares to 

 travel lightly over the arctic snowfields. 



The distribution of arctic hares is confined 

 to the barrens or tundras beyond the limit of 

 trees. They range practically to the land's end 

 of northern Greenland and Ellesmere Land. 

 To the southward in North America they range 

 down the coast of Labrador and across to 

 Newfoundland, where they are limited to the 

 open barrens. They also occur along the 

 shores of Hudson Bay and follow the tundras 

 bordering Bering Sea to the peninsula of 

 Alaska. 



In Ellesmere Land they are reported to be 

 extraordinarily numerous at times in certain 

 little valleys, and tlie fur traders on the coast 

 south of the Yukon Delta informed me of 

 similar gatherings in spring on gently sloping 

 hillsides in that region. Photographs taken in 

 Ellesmere Land show many of these hares 

 scattered over a small area, each crouched in 

 a compact form and all heading in the same 

 direction to face the wind. Such gatherings, 

 at least those in Alaska, occur during the 

 mating period, after which the animals scatter 

 over the area they occupy. 



An account of the big northern hares would 

 be incomplete without reference to the wliite- 

 tailed jack rabbit, the largest of all American 

 hares and a near relative of the arctic species. 

 It attains a weight of twelve pounds or more 

 and appears like a giant of its kind. It has 

 longer legs than the arctic hare and a longer 

 tail. In summer it is grayish or buffy, with a 

 conspicuous pure white tail. Throughout most 

 of its range in winter it becomes pure white 

 except the black tips to the ears, but near the 

 southern border the change to white is not so 

 complete as in the North. The distribution of 

 the white-tailed jack rabbit extends from Min- 

 nesota to the Cascade Mountains and from the 

 Saskatchewan River, in Alberta, south to south- 

 ern Colorado. 



Arctic hares have from one to seven young 

 in a litter each spring. Owing to the climatic 

 conditions under which they exist, it is doubt- 

 ful if more than a single litter is born each 

 year. 



The manner in which animal life adapts it- 

 self to its environment is beautifully illustrated 

 by the arctic hares of north Greenland and 

 Ellesmere Land. There the conditions are rig- 

 orously arctic and continuous winter night ex- 

 tends through a period of several months. In 

 all this region the scanty and dwarfed vegeta- 

 tion is covered with snow and ice the larger 

 part of the year. The hares living there are, 

 with little question, a geographic race of those 

 living farther south, but have developed into 

 larger and stronger animals, with heavier fur, 

 to meet the sterner conditions of life. 



Their claws are nnich larger and heavier, so 

 tliat they may dig tlie snow from tlie hidden 

 herbage. Most marvelous of all, the anterior 

 ends of both jaws are lengthened and the in- 

 cisors set so that they project and meet at an 

 acute angle, thus serving, tweezerlike, more 

 readily to pick out the lowly vegetation im- 

 bedded in the snow. 



In most parts of their range arctic hares are 

 scarce and rarely encountered. Each winter 

 during my residence on the coast of Bering 



