SMALLER MAMMALS OF NORTH AMERICA 



415 



the rough rock walls of the cliffs they inhabit. 

 Their only notes appear to be shrill squeaks 

 and squeals when quarreling among themselves 

 at night. They also express annoyance or 

 alarm by a rapid drumming on the ground 

 with their hind feet, just as is done by some 

 of the hares and rabbits. 



On Santa Margarita Island, in Lower Cali- 

 fornia, I found the most curiously located 

 habitations of these animals I have seen, the 

 bulky stick nests being placed well back in the 

 midst of a mangrove thicket growing in a tidal 

 lagoon. At high tide the mangroves were iso- 

 lated from shore by several rods of water, so 

 that only at low tide were the rats able to go 

 ashore. In going back and forth they followed 

 certain lines of nearly horizontal mangrove 

 stems, the discoloration on the bark plainly in- 

 dicating the routes which finally led to dry 

 land by little trampled roads across the muddy 

 ground bordering the shore. 



Back a little way from shore others of the 

 same species were living in burrows guarded 

 by orthodox stick and trash-pile nests among 

 the cactuses. 



Woodrats, especially in northern localities, 

 gather stores of pinyon or other nuts, potatoes, 

 corn, and any other non-perishable food avail- 

 able to meet the season of storms and scarcity, 

 concealing these supplies in cavities in the nests 

 either above or below the ground. They eat 

 many kinds of fruits, seeds, leaves, and other 

 parts of plants, sometimes including bark of 

 shrubs or small trees and even cactus pads. 



As a rule each nest is occupied by a single 

 rat, but sometimes several may be found in 

 one, and the well-worn trails that so often con- 

 nect the entrances of neighboring nests bear 

 evidence that woodrats have a social disposi- 

 tion. In most localities woodrats are distrib- 

 uted sparingly, but occasionally become so 

 abundant in favorable places on brushy plains 

 that colonies containing hundreds of nests may 

 be found in limited areas. They sometimes be- 

 come so plentiful about ranches as to make 

 serious inroads on grain and other crops. They 

 also give the Forest Service much trouble by 

 digging up the pine seeds planted in their great 

 reforesting nurseries. 



Woodrats are mainly nocturnal in habits and 

 appear to be extremely active throughout the 

 night. Each morning in the vicinity of their 

 nests the light soil shows a multitude of tracks, 

 and in places I have seen little roads in the 

 sand several hundred yards long which they had 

 made by repeated trips to a feeding ground. 



No sooner is a cabin built in the mountains 

 than they move in and establish themselves 

 under the floor, or locate a nest near by and 

 use the house as their nocturnal resort. 

 Throughout the night the patter of their busy 

 feet may be heard as they race about on the 

 floor or rustle about the roof, and often over 

 the sleeping forms of their unwilling hosts. 



Their activities are sources of mingled amuse- 

 ment and vexation. Small, loose articles, in- 

 cluding table knives, forks, and spoons, vanish 

 and all manner of trash, including horse drop- 

 pings, are brought in, thus establishing their 



title to the cognomen of "trade rats." If the 

 owner of a cabin leaves it for a few days, he 

 may find on his return that the rats have taken 

 possession and during his absence have tried 

 to fill it with trash of all kinds, in order to 

 make a comfortable home for themselves. 



At one cabin in the mountains of New Mex- 

 ico where I lived one summer several moun- 

 tain rats made free of the place and at night 

 persistently tried to add our shoes to their nest 

 under the floor. An hour or so after retiring 

 we would hear our shoes scrape slowly across 

 the floor, and in the morning they would be 

 found stuck toe down in the broad crack where 

 the floor ended near the wall. In the woodrat 

 country when small articles are missed from 

 camp it is always worth the trouble to investi- 

 gate the nearest rats' nests. 



Woodrats are plentiful on the Mexican table- 

 land, making their nests under cactuses or 

 thorny agaves, where they are persistently 

 hunted as game by the natives, who prize them 

 as a special delicacy. I saw them regularly 

 sold in the markets of the cities of San Luis 

 Potosi and Aguas Calientes, where the method 

 of marketing them was unique. As soon as 

 they were dug from their nests, their lower 

 incisors w T ere broken off close to the jaw to 

 render them powerless to bite, and then the 

 rats were placed alive in a strong sack and 

 carried to town. 



The vendor would sit on a curb at the mar- 

 ket and either kill and dress them there or 

 shout his wares by telling every one who passed 

 that he had "country rats ; very delicious ; live 

 ones ; fat ones ; very delicious ; very cheap." 

 The natives all praised their delicate flavor and 

 one I had served me as a special courtesy was 

 really good, tasting like young rabbit. 



THE HARVEST MOUSE (Reithrodonto- 

 mys megalotis and its relatives) 



{For illustration, see page 425) 



In size, proportions, and color the harvest 

 mice, of all our American species, most closely 

 resembles the common house mouse. Many 

 of them are decidedly smaller than that animal 

 and they rarely, if ever, exceed it in size. They 

 may be distinguished from the house mouse by 

 their browner colors, more hairy tail and espe- 

 cially by a little groove which extends down 

 the front of each upper incisor. 



The mice of this group include many species 

 and have a wide distribution ranging from Vir- 

 ginia, in the eastern United States, to the Pa- 

 cific, and from North Dakota, Montana, and 

 Washington southward through Mexico and 

 Central America to northern South America. 



They reach their greatest development in 

 number and diversity of species in the region 

 about the southern end of the Mexican table- 

 land, where I have caught them from the trop- 

 ical lowlands, near sea level, up to an altitude 

 of 13,500 feet, at timber-line, on Mount Iztac- 

 cihnatl. 



These delicately proportioned and graceful 

 little beasts are habitants of grassy, weed- 



