Media Contact: Janice Mackey, CDFW Communications, (916) 322-8908
Keystone Species Plays Important Role in Sensitive Food Chain
The California Department of Fish and Wildlife (CDFW) completed its annual survey of the endangered Tipton kangaroo rat (k-rat) at the Semitropic Ecological Reserve in southern San Joaquin Valley.
The annual survey revealed that even with the current drought conditions, k-rats are continuing to survive and reproduce as well as dominate the small mammal community on the reserve. If dry conditions continue, researchers expect lowered reproduction in subsequent years. Nonetheless, population highs and lows are a natural part of their life cycle.
“By monitoring the k-rat population, we can also assess what is happening with other endangered species such as the San Joaquin kit fox, which depend on kangaroo rats as their primary prey, and blunt-nosed leopard lizards, which utilize their burrows,” said Erin Tennant, CDFW environmental scientist.
The k-rat monitoring is also a benchmark for the overall health of the small mammal community on the reserve. Annual surveys on this site and other locations demonstrate that small mammal communities have dynamic populations with shifts in species dominance and abundance.
Using a mark-recapture methodology, the population was assessed by capturing k-rats and other small mammals with live traps. Captured k-rats were marked on the belly with a non-toxic pen to determine on subsequent days if they had been previously captured.
The endangered Tipton k-rats are a sandy brown color with a white underbelly and long tails. Their large back legs enable them to jump up to nine feet in a single bounce, much like a kangaroo, in order to escape predators. They have large heads with big eyes and exceptional hearing which can even detect the silent sound of an owl approaching.
Their specialized metabolism allows them to receive all the water they need from a seed diet which provides the ability to survive in harsh desert climates.
Funding for this research and similar efforts on the reserve’s in the San Joaquin Valley are supported by a State Wildlife Grant (SWG) and administered through the U.S. Fish and Wildlife Service.