State Route 58 Widening Project - Bakersfield Freeways

Chapter 4.
Results: Biological
Resources, Discussion of
Impacts and Mitigation
One federally listed species has potential to occur in the BSA: the San Joaquin kit
fox. The following analysis covers background information on this species, the
presence of this species in the BSA, Avoidance and Minimization Measures, project
effects on the kit fox, compensatory mitigation, and cumulative effects of the TRIP
projects.
4.1. Federally Listed or Proposed Animal Species
Occurrences
4.1.1. Discussion of San Joaquin Kit Fox (Vulpes macrotis mutica)
The San Joaquin kit fox is a federally listed endangered species and a State-listed
threatened species. Kit foxes are primarily nocturnal, but can also be crepuscular or at
times diurnal. Typically, they emerge at sunset to hunt prey such as kangaroo rats
(Dipodomys sp.), black-tailed jackrabbits, desert cottontails, and California ground
squirrels (Thomas Reid Associates 1994). San Joaquin kit foxes prefer open habitats
such as grasslands and open scrubland (USFWS 1998). In the southernmost portion
of their range, the kit fox is commonly associated with valley sink scrub, valley
saltbush scrub, upper Sonoran subshrub scrub, and annual grassland (USFWS 1998).
The species also inhabits grazed grasslands, petroleum fields, urban areas, and land
adjacent to tilled or fallow fields (USFWS 1998). Kit foxes may also occasionally
utilize agricultural lands, including croplands and orchards (Warrick et al. 2007),
although areas that are routinely disturbed by agricultural practices have a limited
capacity to support them.
Kit foxes use dens throughout the year to rear pups, to avoid water loss and heat
stress in summer, to minimize metabolic costs in winter, and to escape predation
(USFWS 1998). While kit foxes prefer loose-textured soils for denning, they are
found on virtually every soil type (Bakersfield and Caltrans 2010).
The San Joaquin kit fox has historically occurred throughout most of the San Joaquin
Valley from San Joaquin County in the north to Kern County in the south (USFWS
State Route 58 Widening Project Biological Assessment 29