Populations of some species of kangaroo rats that are endemic to the San Joaquin Valley, California, have shown substantial declines in recent years. In this paper, we summarize 4 separate studies during which Tipton kangaroo rats (Dipodomys nitratoides nitratoides) have declined to near extinction. Although kangaroo rat populations typically exhibit great fluctuations in abundance, the highly fragmented and isolated condition of current populations coupled with declining numbers and naturally low fecundity threaten species survival. Many of the smaller populations may have been extirpated and many of the larger populations may not be viable. Extinction of the species may be avoided by expanding the size and suitability of existing preserves and natural areas, creating connections between those habitats that are suitable for genetic exchange, and implementing appropriate habitat management actions. We discuss some ongoing and planned actions that may contribute to achieving these goals.
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