One candidate (D. nitratoides brevinasus) and three endangered kangaroo rats (Dipodomys ingens. D. n. nitnatoides, D. n. exilis) occur in the San Joaquin Valley. California. Loss and fragmentation of their habitats because of cultivation were the main causes of endangerment. The major barriers to recovery of these and other species of the region are: the large size of the area (over 10 million acres) which renders insignificant the small amount of funds spent on range-wide population assessments; spreading scarce funds and administrative actions over many threatened and endangered species (1 5 species of plants and animals in the San Joaquin Valley are listed); giving land acquisition priority over habitat protection; and failure of the administrative processes dealing with endangered species to ensure funding needed for research and monitoring. There are no programs for monitoring populations. Data needed to conduct viability analyses, estimate size of habitat units required for species recovery, manage species habitat, and regulate land uses are mostly unavailable. We review the knowledge needed for management and recovery of listed and potentially jeopardized kangaroo rats in the San Joaquin Valley Region, list problems that pose major barriers to recovery, analyze research methods, and present a suggested program of research to support recovery planning.
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