Description
This kangaroo rat is part of the ''Range and habitat
Stephens's kangaroo rat was once found in limited regions in southern California,Brock, Rachel E., and Douglas A. Kelt. "Influence of Roads on the Endangered Stephens Kangaroo Rat (''Dipodomys Stephensi''): Are Dirt and Gravel Roads Different?" Biological Conservation, vol. 118, no. 5, 2004, pp. 633–640. . but now due to development leading to habitat loss the populations are now only found in select nature reserves in San Jacinto Valley, San Bernardino, and northwestern San Diego counties in California. Roads surround all the locations that they live or are found to live. This creates problems if they are paved and used often because of car fatalities. However, the Stephens's kangaroo rat has been found to inhabit and colonize dirt roadsides. This may be due to the type of habitat they prefer. The Stephens's kangaroo rat prefers sparsely vegetated areas, about 15% cover, that have annual grasslands with low shrub cover of sagebrush. Further more they like seral stage, intermediate, plant communities that are retained by fires, grazing, and or agriculture. They are also limited to gravely soil that cannot be too dense. This is because they have to burrow into it to make their tunnel systems for nesting and storage.Food and foraging behavior
With living in sparsely covered habitat and making bare spots in the land the rats create trails. They use these trails to get around easily from food source to food source. These trails lessen some of the dangers of foraging, as they make for a clear path for fast getaways leading straight to their burrow. Even though they move along their cleared trails to go to different food sources and the use to escape terrestrial predators they have to worry about aerial predators. They deal with this by foraging under the remaining shrubs that are left standing for seeds. Seeds are the on the main course for this kangaroo rat, and that means that they are a granivorous. In doing dissection of kangaroo rat stomachs it was found that their diets composed of red brome (''Bromus rubens''), common Mediterranean grass (''Schismus barbatus''), and red-stemmed filaree (''Erodium cicutarium''). All of these species were introduced to North America. Ants, chewing lice, and darkling beetles were also found in their stomachs but not as prominent as the plant species listed above.Impacts on their environment
Stephens's kangaroo rats have been shown to have a keystone like effect on their sounding environment. One way this is seen is by digging burrows. By digging burrows the soil fertility increases and the water infiltration increase as well. This then leads to larger plant diversity. Seed caching is also another means of how they change their environment. Seed caching is when they bury seeds to hide them so they can come back later for them. They don't always find them again or eat them and this leads to a greater diversity of plants around their burrow. Erodium, which is an invasive species, is able to outcompete native species. This then diminishes the natural diversity within the habitat. Stephens's kangaroo rat is able to help decrease the impact by controlling the impact of the Erodium by keeping the numbers down. These kangaroo rats clear patches of ground, which allows it to keep a seral stage environment. This removal of vegetation also keeps down the number of granivorous rodents down. This then allows for plants to have a greater chance to disperse and reach full development.Population ecology
Due to the dispersal and location of the populations of kangaroo rats they have experienced isolation from other populations. In two populations a haplotype, haplotype A, was found, but it was not found in a populations further away. This suggests that there is a decrease of gene flow between the different populations of kangaroo rats. Another haplotype type designates a different story as to the genetics of this species. A haplotype CC is widespread but not in a random fashion. The haplotype CC mostly dominates in the south with very little appearance in the north and central regions. This high frequency of haplotype CC in the south and the lack of different haplotypes unrelated to haplotype CC suggest that there was a population bottleneck that occurred in the south. It seem likely that the population of southern Kangaroo rats now would have repopulated from a small group in the south due to them living in a disconnected valley from the central and northern populations.Metcalf, Anthony E., et al. "Geographic Patterns Of Genetic Differentiation Within The Restricted Range Of The Endangered Stephens Kangaroo Rat ''Dipodomys stephensi''." Evolution, vol. 55, no. 6, 2001, p. 1233. .References
{{Taxonbar, from=Q308213 stephensi Endemic fauna of California Mammals of the United States Fauna of Riverside County, California Natural history of the Peninsular Ranges Endangered fauna of California Mammals described in 1907 Taxonomy articles created by Polbot ESA endangered species