RATS AND MICE FAMILY 



245 



summer is brown or brownish gray with a black 

 stripe down the back, becomes almost snow- 

 white in winter. 



The variety known as Nelson's Lemming oc- 

 curs in Alaska. E. W. Nelson was able to take 

 some of these Lemmings alive. He states that 

 they were amusing, inoffensive little creatures 

 and from the first allowed themselves to be 

 handled without attempting to bite. " They 

 would climb up into my hand and from it to 

 my shoulder without a sign of haste or fear, 

 but with odd curiosity, keep their noses con- 

 tinually sniffing and peered at everything with 

 bright bead-like eyes, ^\l^en eating they held 

 their food in their fore paws." 



Lemmings have the appearance of small 

 Rats. They feed mainly on mosses, stalks and 

 roots of grasses, and the tender shoots of birch, 

 and in searching for food make long galleries 

 under the snow. They make nests, usually of 

 hair and rye grass : they have two broods a year ; 

 and produce four to six young at a birth. It 

 is often stated that American Lemmings do not 

 migrate as those of the Old \\'orld do : but Rae 

 observed some as migrating northward near the 

 mouth of the Coppermine River early in June, 

 1 85 1. An account of this migration is given by 

 him in the Journal of the Linnacan Society 

 as follows : " I am not aware if it is generally 

 known that the Lemmings of North America 

 migrate much in the same manner as do those of 

 Norway and Sweden. When traveling in June, 

 1851, southward from the Arctic Coast along 



the west bank of Coppermine River, and north 

 of the Arctic Circle, we met thousands of these 

 Lemmings speeding northward, and as the ice 

 on some of the smaller streams had broken up, 

 it was amusing to see these little creatures run- 

 ning backward and forward along the banks 

 looking for a smooth place with slow current 

 at which to swim across. Having found this, 

 they at once jumped in, swam very fast, and on 

 reaching the opposite side gave themselves a 

 good shake, as a dog would, and continued their 

 journey as if nothing had happened." 



One species of the Hudson Bay Lemming is 

 found in abundance arouiid Fort Churchill and 

 on the Barren Grounds. These Lemmings fre- 

 quent the gravelly ridges, the remains of old 

 sea-beaches, bordering the bay. Mr. Edward 

 A. Preble who, with his brother, captured about 

 120 specimens in 1900, states that they make 

 burrows but no runways. The only food found 

 in the burrows was a few leaves of the bear- 

 berry. Each burrow seemed to be tenanted by 

 only a single individual, except in the case of 

 a mother Lemming and young. The breeding 

 season seemed to be nearly over in August, and 

 every litter found consisted of three. The young 

 " were very readily tamed and took rolled oats 

 and crumbs of bread within a few hours of 

 their capture. They sat on their haunches and 

 held their food in their fore feet like Squirrels. 

 The old ones fought viciously when captured, 

 and their sharp incisors and strong jaws made 

 them somewhat formidable." 



Other Names. — Eastern Vole. 

 Mouse. 



General Description. — .'\ medium-sized Mouse, short- 

 tailed, with body rather heavier than that of the com- 

 mon House Mouse. Head large and blunt; ears low 

 and almost hidden in the fur; body thick-set; tail 

 short, about twice as long as hind foot ; fur long, 

 overlaid with coarse hairs; legs short; soles of feet 

 naked and having six plantar tubercles ; molar teeth 

 with a great number of sharp angles in the enamel, 

 ■thus furnishing many sharp cutting edges ; mammae 

 eight ; general color dusky gray or brownish. 



Dental Formula.— Incisors, r-' ; Canines, '^^ 



' I — I ' ' o — o 



3—3 



COMMON MEADOW MOUSE 

 Microtus pennsylvanicus ( Ord) 

 Field X'ole. Field 



Pre- 



molars, — — ; Molars, 



=16. 



Pelage. — Adults: Sexes identical. Summer. Upper 

 parts, dull chestnut-brown varying to bright yellowish- 

 chestnut, darkened along back with coarse black hairs ; 



under parts, dusky gray or tinged with cinnamon ; 

 feet brownish ; tail dusky above, slightly paler below. 

 Winter. Colors duller and uniformly grayer through- 

 out; tail indistinctly bicolor. Young: Uniform dark 

 slate-gray. 



Measurements. — Total length, 6.7 inches ; tail ver- 

 tebrae, nearly 2 inches ; hind foot. .8 inch. 



Range. — Eastern United States and westward to 

 Dakota and Nebraska. 



Food. — Omnivorous to a considerable degree, but 

 principal articles of diet, grass, grain and green vegeta- 

 tion. 



Remarks. — Meadow Mice are found in so many 

 habitats, and are so susceptible to environmental condi- 

 tions, that they have become differentiated in many 

 different details such as color, size, character of pelage, 

 length of tail, number of little pads on the feet, etc. 

 There are at least 76 species and subspecies in this 

 country. Only a few may be listed here. 



