MORRO BAY KANGAROO RAT Dipodomys heermanni morroensis (Merriam) 



Order: RODENTIA Family: HETEROMYIDAE 



Distinguishing characteristics : "The darkest colored of all known kangaroo rats" 

 (Grinnel, 1922) . "The dark coloration of D. h. jolonensis is further intensified in 

 D. h. arenae and reaches an extreme in morroensis" (Boulware, 1943). Dorsal color 

 tawny-olive, clearest on sides and strongly overwashed with blackish on tops and 

 sides of head and down middle of back; facial cresents broad, continuous and jet black, 

 involving whole top of nose for at least 5 mm . ; dorsal and ventral tail stripes almost 

 solid black and very broad, each more than twice width of either white lateral stripe; 

 tail weakly crested and tufted; white band across outer side of flank usually incomplete 

 or lacking. 



Present distribution : Restricted to sandy soils comprising an area of about 1.7 square 

 miles on the south side of Morro Bay, San Luis Obispo County, California. 



Former distribution : Probably about the same since historic times , but possibly also 

 including an area on the north side of Morro Bay. 



Status : Suitable habitat now reduced to approximately 2 square miles; habitat 

 destruction continuing . 



Estimated numbers : Population density estimated to average five per acre; total 

 population probably less than 3,000. 



Breeding rate in the wild : Breeding activity is greatest during the spring and summer, 

 but some breeding may also occur during the fall and winter. Females probably bear 

 one or two litters annually , each containing two to four young . 



Reasons for decline : Destruction of habitat, especially by community development; 

 predation by house cats . 



Protective measures already taken : Taking and possession prohibited by State law. 

 Extension of Montana de Oro State Park places additional habitat under public stewardship . 



Measures proposed : Establishment of proposed Morro Bay Ecological Reserve would 

 provide additional protection. 



Number in captivity : Unknown, but probably very few. 



Breeding potential in captivity : Probably fairly good with proper facilities and 

 management. 



Remarks : This kangaroo rat is closely restricted to moderately compacted, sandy soils 

 covered by fairly open scrub vegetation. Its range is bordered by coastal sand dunes, 

 salt marsh, cultivated land, and chaparral. Some chaparral areas exist within the range 

 and can be temporarily colonized following fires. Significant range extensions are pre- 

 vented, however, by surrounding hard soils. Destruction of the habitat began in the early 



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