252 



MAMMALS OF AMERICA 



MUSK-RAT 

 Ondatra (or Fiber) zibethica { Liunacits) 



Other Name. — Musquash. 



General Description.— A large rat-hke rodent with 

 long, naked, vertically compressed tail. Head broad 

 and blunt ; ears almost hidden in long fur ; body thick- 

 set, heavy; tail long, about one-half total length; legs 

 short ; hind feet specialized, long, with toes partly 

 webbed ; tail much deeper than wide, almost naked and 

 scaly, with scattered long hairs; pelage of two coats, 

 a dense soft underfur and long outer coat of hard 

 glistening hairs. 



Dental Formula. — Incisors, 

 molars. 



; Canmes, ; Fre- 



— o , 

 — o ' 



Molars, ^-J=i6. 



3~3 



Pelage. — Adults : Sexes identical. Seasonal varia- 

 tion very slight. General color dark chestnut brown 

 above; underpants brownish-white; underfur every- 

 where slaty-black ; throat whitish ; chin with brown 

 spot ; feet brown ; tail blackish-brown ; individuals vary 

 from this pattern to much darker. Young : Slaty-gray. 



Measurements. — Total length. 2i inches; tail verte- 

 brae. 10 inches ; hind foot. 3.5 inches. Weight. 2 pounds, 

 4 ounces. 



Range. — Southeastern Canada, northeastern and east 

 central United States. 



Food. — Quite omnivorous; besides many types of 

 vegetation such as stalks and roots of flags, lilies and 

 reeds, considerable animal food is eaten, mainly clams, 

 fish and insects. 



Re.Tiarks. — The Musk-rat is in reality only a highly 

 specialized, enlarged Vole, and this relationship is 

 shown in a number of characters. They are widely 

 spread over North America from northern Mexico to 

 the Arctic Coast, and have become differentiated into 

 fourteen species and subspecies, of which only a few 

 need be cited below. 



Rel.med Species 



Musk-rat. — Ondatra zibethica zibethica (Linnaeus). 

 Typical animal as described above. From New Bruns- 

 wick and Quebec west to Minnesota, south to northern 

 Georgia, Arkansas, and south along .Atlantic seaboard 

 to Delaware Bay. 



Large-toothed Musk-rat. — Ondatra zibethica macro- 

 don (Merriam). Color darker and richer; teeth larger 

 than common Musk-rat. ^liddle .Atlantic Coast region 

 of the United States. 



Labrador Musk-rat. — Ondatra ziebethica aquilonia 

 (Ban.nsK Smaller and blacker than the common Musk- 

 rat. Labrador. 



Pallid Musk-rat. — Ondatra zibethica pallida 

 (Mearns). .About two-thirds as large as common 

 Musk-rat ; coloration paler. Colorada River Valley, 

 California, and .Arizona, east to the Rio Grande Valley 

 in New Mexico. 



Oregon Musk-rat. — Ondatra zibethica occifitalis 

 (Elliot). Largest of the Musk-rats; coloration dark. 

 Northern Willamette \'alley and coast of Oregon. 



Photograph by S. A. Lottndge 



YOUNG MUSK-RAT 

 Everything is food that comes to the Musk-rat's table 



