Black-tailed Prairie Dog or Marmot
Cynomys ludovicianus

HABITAT & DISTRIBUTION: Once found throughout the US from Canada in the north to Mexico in the south. Today, thought of as pests they have been eradicated by ranchers and are restricted to a few isolated populations on the mid grass prairies from central Texas to the Canadian border. These prairie dogs are never found in moist areas.  

DESCRIPTION:  Cynomys ludovicianus varies in length between 352 and 415 mm.  Males tend to be longer and 10 to 15% heavier than females, weighing in between 850 and 1,675 g.  Weight varies seasonally, with both males and females reaching their highest weights in the autumn, and lowest in winter.  Black-tailed Prairie Dogs are generally tan in colour, with a lighter coloured belly. Their tail has a black  tip on it, which is where their name comes from. They have small ears, but keen hearing, and small, dark eyes, with good vision.

Gestation is from 33 to 38 days, litters ranging from 1-8 are born blind, naked, and mostly helpless. Fur is evident by the age of 3 weeks, and eyes are open by approximately 5 weeks of age.  Pups may nurse from females other than their own mother.