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Title: An assessment of techniques for monitoring San Joaquin kit fox population abundance on Naval Petroleum Reserve No. 1, Kern County, California

Abstract

The monitoring of San Joaquin kit fox (Vulpes macrotis mutica) population abundance on Naval Petroleum Reserve No. 1 (NPR-1) by the US Department of Energy (DOE) is one aspect of compliance with the Endangered Species Act of 1973. Monitoring of the kit fox population is essential to determine the need for specific management programs, to assess the impacts of development activities, to evaluate the results of specific management programs, and to gather information on kit fox biology and ecology as they relate to other aspects of the NPR-1 environment. Several techniques are available to monitor population abundance, but the choice of methods used is dependent upon the specific objectives of the monitoring program. The inherent problem with most available techniques is the lack of uniformity of procedures and statistical repeatability, and the need for validation of indices and population estimates against known populations. If sufficient numbers of foxes can be captured, closed population models using capture-recapture data provide reasonable estimates of population size. Capture data can also be used to determine the minimum trappable population, and the minimum population size during those sessions when fewer than 40 foxes are trapped. The scent-station survey is the best method available for estimatingmore » relative kit fox abundance.« less

Authors:
Publication Date:
Research Org.:
EG and G Energy Measurements, Inc., Goleta, CA (USA). Santa Barbara Operations
OSTI Identifier:
6361705
Report Number(s):
EGG-10282-2159
ON: DE87012715
DOE Contract Number:
AC08-83NV10282
Resource Type:
Technical Report
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; FOXES; MONITORING; NAVAL PETROLEUM RESERVE; CALIFORNIA; COMPARATIVE EVALUATIONS; POPULATIONS; ANIMALS; FEDERAL REGION IX; GEOLOGIC DEPOSITS; MAMMALS; MINERAL RESOURCES; NORTH AMERICA; PETROLEUM DEPOSITS; RESERVES; RESOURCES; USA; VERTEBRATES; 510500* - Environment, Terrestrial- Site Resource & Use Studies- (-1989)

Citation Formats

Harris, C.E.. An assessment of techniques for monitoring San Joaquin kit fox population abundance on Naval Petroleum Reserve No. 1, Kern County, California. United States: N. p., 1987. Web.
Harris, C.E.. An assessment of techniques for monitoring San Joaquin kit fox population abundance on Naval Petroleum Reserve No. 1, Kern County, California. United States.
Harris, C.E.. Wed . "An assessment of techniques for monitoring San Joaquin kit fox population abundance on Naval Petroleum Reserve No. 1, Kern County, California". United States. doi:.
@article{osti_6361705,
title = {An assessment of techniques for monitoring San Joaquin kit fox population abundance on Naval Petroleum Reserve No. 1, Kern County, California},
author = {Harris, C.E.},
abstractNote = {The monitoring of San Joaquin kit fox (Vulpes macrotis mutica) population abundance on Naval Petroleum Reserve No. 1 (NPR-1) by the US Department of Energy (DOE) is one aspect of compliance with the Endangered Species Act of 1973. Monitoring of the kit fox population is essential to determine the need for specific management programs, to assess the impacts of development activities, to evaluate the results of specific management programs, and to gather information on kit fox biology and ecology as they relate to other aspects of the NPR-1 environment. Several techniques are available to monitor population abundance, but the choice of methods used is dependent upon the specific objectives of the monitoring program. The inherent problem with most available techniques is the lack of uniformity of procedures and statistical repeatability, and the need for validation of indices and population estimates against known populations. If sufficient numbers of foxes can be captured, closed population models using capture-recapture data provide reasonable estimates of population size. Capture data can also be used to determine the minimum trappable population, and the minimum population size during those sessions when fewer than 40 foxes are trapped. The scent-station survey is the best method available for estimating relative kit fox abundance.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Apr 01 00:00:00 EST 1987},
month = {Wed Apr 01 00:00:00 EST 1987}
}

Technical Report:
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  • San Joaquin kit fox (Vulpes macrotis mutica) population size was estimated semiannually on the US Department of Energy's Naval Petroleum Reserve No. 1, Kern County, California, between December 1980 and August 1986 using capture-recapture data. Estimates were derived using a calendar graph (minimum population size) and appropriate models that allowed for unequal probability of capture. A total of 469 foxes were captured 930 times. There was a significant decline between the peak population estimates (164, minimum population size; 262, closed population model estimate) obtained in winter 1981 and the estimates for winter 1985 (41, minimum population size; 56, closed populationmore » model estimate). Population trends for the portion of the study area affected by petroleum development activities did not differ from those observed in undeveloped habitats. Closed population model tests provided evidence of behavioral response and heterogeneity of capture probability in the kit fox. The proportion of animals known to be alive but untrapped each session ranged between 14% and 77% which also indicated variable trap response. Closed population models provided reliable estimates of population size and its variance when the number of individual foxes captured was at least 40 to 50. Use of the Jolly-Seber open population model with this data set was rejected by the goodness-of-fit test because of the small number of marked foxes that were captured each trapping period and the small number of marked foxes from each release that were eventually recaptured.« less
  • Between 1980 and 1986 DOE sponsored field studies to gather sufficient information to determine the status of the species on Naval Petroleum Reserve-1 and to evaluate the possible effects of MER. Transect surveys were conducted in 1979 and 1984 to document the distribution and relative density of fox dens. Radiotelemetry studies were initiated to provide information on reproductive success, den use patterns, responses to petroleum field activities, food habits, movement patterns and home ranges, and sources and rates of mortality. Techniques for conducting preconstruction surveys to minimize possible negative effects of MER activities on foxes plus a habitat restoration programmore » were developed and implemented. DOE determined during this biological assessment that the construction projects and operational activities necessary to achieve and sustain MER may have adversely affected the San Joaquin kit fox and its habitat. However, the direct, indirect, and cumulative effects of MER will not jeopardize the continued existence of the species because: (1) results of the extensive field studies did not provide evidence that MER effected negative changes in relative abundance, reproductive success, and dispersal of the species; (2) a successful policy of conducting preconstruction surveys to protect kit fox, their dens, and portions of their habitat was initiated; (3) the Secretary of the Interior did not designate critical habitat; (4) a habitat restoration plan was developed and implemented; (5) a monitoring program was implemented to periodically assess the status of kit fox; (6) a coyote control program was established with FWS to reduce predation on fox; and (7) administrative policies to reduce vehicle speeds, contain oil spills, restrict off-road vehicle (ORV) travel, and to prohibit hunting, trapping, livestock grazing, and agricultural activities, were maintained to protect kit fox.« less
  • The U.S. Department of Energy proposes to drill exploratory wells on two sections, 8B and 18H, within Naval Petroleum Reserve No. 2 in western Kern County, California. The proposed sites are thought to provide habitat for the endangered San Joaquin kit fox and blunt-nosed leopard lizard, as well as two sensitive species: the giant kangaroo rat and San Joaquin antelope ground squirrel. The objective was to assess the possible impacts of the exploratory drilling on these species and their essential habitats. Although 23 potential San Joaquin kit fox den sites were found during surveys of a total of 512 hamore » (1280 acres) surrounding both well sites, no burrows were closer than 30 m from proposed disturbance, and most were over 200 m away. Two blunt-nosed leopard lizards were observed on private land within 8B, one was observed on private land in 18H, and two were seen on DOE portions of 18H. No evidence of blunt-nosed leopard lizards was gathered in the immediate vicinity of either proposed well site. Although 5 ha of habitat will be disturbed, there is no evidence to indicate any of the species has burrows on-site that will be lost during land clearing. Loss of habitat will be mitigated during the cleanup and restoration phases when disturbed areas will be revegetated. Increased traffic, human activities, noise and ground vibration levels, as well as illumination throughout the night, may disturb the fauna. However, these species have adapted to intensive human disturbances on Elk Hills without obvious negative effects. The short duration of the project should allow any displaced animals to return to the sites after drilling ceases.« less
  • The proposed site is thought to provide habitat for the endangered an Joaquin kit fox and blunt-nosed leopard lizard, as well as the giant kangaroo rat and San Joaquin antelope ground squirrel. The objective of this study was to assess the possible impacts of the exploratory drilling on these species and their essential habitats. The proposed project will have four phases: (1) surveying; (2) site preparation; (3) drilling, logging, and testing; and (4) cleanup and restoration. During site preparation approximately 1.5 acres of vegetation and surface soils will be removed for an access road and well pad. During a 20-daymore » drilling, logging, and testing phase, there will be increased vehicular traffic, human activities, noise and ground vibrations, and illumination during the night. Although 1.5 acres of habitat will be disturbed, there is no evidence to indicate any of the species has burrows on-site that will be lost during land clearing. Loss of habitat will be mitigated during the cleanup and restoration phases when disturbed areas will be revegetated. Increased traffic, human activities, noise and ground vibration levels, as well as illumination throughout the night, may disturb the fauna. However, these species have adapted to intensive human disturbances on Elk Hills without obvious negative effects. The most direct threat to the species is the possibility that they might be killed by vehicles. Since the project poses so few threats to individual endangered or sensitive species, and since minor habitat disturbances will be mitigated during a restoration program, it is unlikely that completion of the project jeopardizes the continued existence of any of the species or their essential habitats. (ERB)« less
  • Locations of 945 dens used by radiocollared San Joaquin kit foxes (Vulpes macrotis mutica) on or adjacent to the US Department of Energy's Naval Petroleum Reserve No. 1 (NPR-1) in western Kern County, California between 1980-1987 were recorded on maps and stored within a computer-compatible data base. Most (516 of 887) typical subterranean dens of this endangered species were found in undeveloped portions of 65 sections, but most (41 of 58) atypical dens (dens in man-made structures) were found in developed portions of 26 sections. Program managers can plan construction, maintenance, and operational activities on NPR-1 in ways that avoidmore » potential conflicts with the conservation of kit fox dens by using the section maps provided in this report or by accessing the computerized data base through the Endangered Species Contractor, EG and G Energy Measurements, Inc. 20 refs., 3 figs, 1 tab.« less