MAMMALS. 61 



sity of roads. They clamber over logs and even climb trees, but 

 generally keep under cover as much as possible to avoid their enemies. 

 While mainly nocturnal they are often caught in traps in the woods 

 during the daytime and especially toward evening, when they seem 

 to be most active. Their food consists chiefly of green grass and a 

 great variety of small plants and seeds. Their stomachs usually con- 

 tain a combination of green-plant tissue and the white starchy part 

 of seeds, but they are always eager for rolled oats or any kind of 

 grain that is offered as trap bait. They seem, however, not to be 

 inquisitive and rarely get into camp supplies or do any mischief 

 except where provisions are left on the ground unprotected. In fact, 

 their presence is rarely discovered by the camper or even by the ex- 

 perienced woodsman and fur trapper who spend much time in their 

 habitat. A few traps, set in proper locations, will soon reveal the 

 presence of the mice, and a tin can at the bottom of a hole in the 

 ground will often be found occupied by some that have tumbled in 

 during the night. 



Four to six embryos in females taken for specimens indicate 

 the size of their families; but little is known of their actual breeding 

 habits other than what is learned from an occasional nest of hairless 

 young found under an old log, board, or other protecting cover. 

 Much remains to be learned of the habits of such obscure small mam- 

 mals by those who have time and patience to make careful' studies of 

 them on their home grounds. 



LARGE-rooTED Meadow Mouse : Mlcrotus rwhardsoni macropus 

 (Merriam). — The largest of all the meadow mice, often measuring 8 

 to 10 inches in total length, are common along the streams and in the 

 meadows and wet places throughout the Canadian and Hudsonian 

 Zones of the park. They are semiaquatic in habits and are rarely 

 found far from water. In many places their large trails and runways 

 extend through the shallow^ water of the marshes or lead into the 

 edges of small streams or ponds and reappear on the opposite sides. 

 Often along the creek banks one will be seen to jump into the water 

 and swim across the stream dee]) below the surface. Their dense fur 

 and large hind feet are well adapted to a partially aquatic life, even 

 in the cold streams up to the snow l)anks. Their burrows often 

 honeycomb the creek banks, and their summer nests, in which the 

 young are raised, are found in cavities to which these burrows lead. 

 In winter some of their big grassy nests are placed on the ground 

 under the deep cover of soft snow, and as the snow disappears in 

 spring their runways show a network of tunnels over the surface. 



Grass and sedges form the principal part of their food in both 

 winter and summer. In winter they are gathered from the surface 

 of the ground under snow, and in summer the tender shoots are cut 



