Order Lagomorpha

Pikas, Hares, and Rabbits

At least 92 species of lagomorphs are distributed throughout the world.  This order includes the hares and rabbits (family Leporidae) and pikas (family Ochotonidae).  Mammals assigned to this order superficially resemble rodents, but lagomorphs differ from rodents in several essential features.  One is the peculiar tandem arrangement of the front (incisor) teeth, with a large tooth in front on each side and a small peg-like tooth directly behind it.  Also, the number of premolars is 2/2 or 3/2 (2/1 or 0/0 in rodents), so that the total number of teeth is 26 or 28 and never as few as the 16 to 22 found in rodents.  

This group of mammals is largely diurnal or crepuscular in habit; the food is almost entirely vegetable manner -- grasses, forbs, and bark of trees and shrubs.  Because of their usually large size and food preferences, lagomorphs frequently come into conflict with grazing, agriculture, and forestry interests.  No lagomorphs hibernate. 

 

KEY TO THE HARES AND RABBITS OF TEXAS

1. Interparietal bone indistinct to absent; ears large (>100 mm from notch); tail with black dorsal stripe.  Lepus californicus (black-tailed jackrabbit).

Interparietal bone distinct; ears shorter (<100 mm from notch); tail entirely white or brown in color ...................... 2

 

2. Greatest length of skull in adults >75 mm; total length of adults usually near 500 mm; dorsal surface of hind foot brown in color; distinct cinnamon-colored eye ring.  Sylvilagus aquaticus (swamp rabbit).

Greatest length of skull in adults <75 mm; total length of adults usually <450 mm; dorsal surface of hind foot white in color; eye ring whitish to buff in color........... 3

 

3. Ear 65% to 85% as long as hind foot; hind foot usually <90 mm; ear usually >60 mm; auditory bullae large and coarse in texture; nuchal patch typically tan in color. Sylvilagus audubonii (desert cottontail). 

Ear 50% to 63% as long as hind foot; hind foot usually >90 mm; ear usually <60 mm; auditory bullae small and smooth in texture; nuchal patch typically reddish in color ..................... 4

 

4. Hind foot near 100 mm; ear near 70 mm; premolar enamel patterns highly complex and convoluted.  Sylvilagus robustus (Davis Mountains cottontail).

Hind foot near 90 mm; ear near 55 mm; premolar enamel patterns smooth walled and simple.  Sylvilagus floridanus (eastern cottontail).

 

Family Leporidae

Hares and Rabbits

There are 11 genera and 61 species of rabbits and hares in the world.  Two genera and five species occur in Texas.  Rabbits are small (relative to hares), are solitary to gregarious, and give birth to altricial (poorly developed) young.  Hares are generally larger and often solitary and give birth to precocial (well-developed) young.  All rabbits and hares are adapted for foraging in open habitats, have large ears, and are capable of instant flight and considerable speed to escape predators.  They are strictly vegetarian, feeding on a variety of grasses and forbs. 

 

 

From The Mammals of Texas, Seventh Edition by David J. Schmidly and Robert D. Bradley, copyright © 1994, 2004, 2016.  Courtesy of the University of Texas Press.