Distribution and Habits of Kangaroo Rats at Morro Bay

Low genetic diversity in an endangered species: recent or historic pattern?

“…This habitat is geographically isolated from that of other populations (subspecies) by approximately 10 km. The population size in 1957 (and presumably earlier) was estimated to be 8000 individuals (Stewart and Roest, 1960). By 1986, however, only 50 individuals remained with available habitat having been reduced by 98% to 12.6 ha.…”

“…This subspecies occurs as a single population in a small sand dune complex (567 ha.) along the coast of Central California (Stewart and Roest, 1960). Historic genetic subdivisions are considered very unlikely due to the small and contiguous nature of the suitable habitat (Stewart and Roest, 1960).…”

“…along the coast of Central California (Stewart and Roest, 1960). Historic genetic subdivisions are considered very unlikely due to the small and contiguous nature of the suitable habitat (Stewart and Roest, 1960). This habitat is geographically isolated from that of other populations (subspecies) by approximately 10 km.…”

Native Small Mammal Use of an Invasive Grass: Heermann's kangaroo rats (Dipodomys heermanni) and Veldt grass (Ehrharta calycina) in Coastal California

“…Veldt grass is becoming the dominant plant in the coastal dune scrub community on the California central coast and has changed the vegetative composition of these coastal communities (Kelt, 1988). (Kelt, 1988 (Stewart andRoest 1960, Congdon andRoest, 1975, Kofron andVillablanca submitted). Therefore, Veldt grass is typically regarded as being detrimental to kangaroo rats.…”

“…Previous research on the Lompoc kangaroo rat focused on gaining insight into Morro Bay kangaroo rats' food and habitat preferences (Stewart andRoest, 1960 andCongdon andRoest, 1975), breeding behavior and captive breeding programs (Roest, 1991), reintroductions of captive kangaroo rats into the wild (Gambs, 1986), and competitors (Gambs, 1986, reviewed in Kofron and Villablanca submitted seeds had significant effects on local plant community structure, since test plots that excluded kangaroo rats showed a significant change from desert shrubland to grassland exhibiting at least a threefold increase in tall perennial and annual grasses along with an increase in arid grassland rodents (Brown and Heske, 1990). Kerley et al (1997) merriami and D. ordii) were responsible for the grass cutting under field conditions.…”