The Kangaroo Rats of California: endemism and conservation of keystone species

Abstract

This review describes the great diversity and endemism of Kangaroo Rats Dipodomys spp. in California. Many species are formally listed as endangered and others are likely to be listed in the near future. We review recent efforts to conserve these small bipedal rodents. We argue that they deserve special emphasis because they have been shown to play key roles in ecosystem structure and composition. Indeed, many of the plant communities occupied by Kangaroo Rats have now been identified as at risk because of excessive habitat destruction and fragmentation. It is clear that preservation of Kangaroo Rats and their plant communities will not be achieved through simply setting aside blocks of habitat as reserves. Conservation areas will require active management in order to maintain existing biodiversity, but further studies are required to ascertain how best to manage these communities. We believe that Kangaroo Rats are important subjects for management studies and ecosystem monitoring. Preliminary studies of the size of reserves required to maintain viable populations of one species show that despite the often high abundance of Kangaroo Rats (35 animals/ha), large areas (>5 000 ha) will be required. Therefore, considerable biodiversity is likely to be protected by focusing on these species, particularly if conservation and recovery efforts are applied on a regional scale.