}V1ESI.} RETURNING MATERIALS: Place in book drop to LIBRARJES remove this checkout from .—:—. your record. FINES win be charged if book is returned after the date stamped below. .. . . k a EFFECTS OF KERN COUNTY CATTLE RANCHING ON CALIFORNIA CONDOR HABITAT BY Cynthia Dawn Studer A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF ARTS Department of Geography 1983 ABSTRACT EFFECTS OF KERN COUNTY CATTLE RANCHING ON CALIFORNIA CONDOR HABITAT BY Cynthia Dawn Studer The California condor, an endangered species, is dependent upon the livestock ranches of southern California for its food supply and feeding habitat. This study reviews four factors which may be contributing to the condors' decline (an inadequate food supply, accidental poisoning, shooting, and habitat loss) and discusses the relationship between current ranch practices and these factors. Data, obtained by interviewing Kern County cattle ranch operators, categorized ranches by size, length of operation, and ownership type. Operator responses were summarized and mapped to determine the extent and location of ranch activities. Results indicate that there are no differences among the responses given by Operators of different ranch types. The condors' food supply appears to be adequate to support the existing population. Shooting and use of poisons are widespread and may create hazardous feeding conditions. Most ranchers participate in programs which help them remain in business and indirectly help preserve condor habitat. ACKNOWLEDGEMENTS This thesis could not have been completed without the assistance of many people. I am most grateful to the National Audubon Society for funding my research and to all of the staff at the Condor Research Center for providing insight on the condor and its habitat problems. John Ogden deserves special thanks for backing my efforts from beginning to end and for his patience when this work took priority over all other aspects of my job. I would also like to thank my advisor, Dr. Michael Chubb, for his assistance throughout the years of research and writing even when it required long distance communications. Special thanks to Richard Herleikson who helped with the maps and who was always there to encourage me when I was overwhelmed by the work ahead. Thanks also to Sheila Allen-Weiss for doing a superb typing job and for working so hard to meet the submission deadline. Last, but not least, my parents deserve my greatest appreciation. Their love, support, and faith in my abilities has always been freely expressed. ii TABLE OF CONTENTS Page LIST OF TABLES . . . . . . . . . . . iii LIST OF FIGURES . . . . . . . . . . . iv CHAPTER I. INTRODUCTION............... ....... ................ II. III. IV. Context of the Problem............................ Population Size and Distribution............... Condor Recovery Programs and Problems.......... The Importance of Land Use and Management......... Problem Statement................................. Goals of the Study. ..... .......................... Hypotheses......... ......... ................. ..... Related Research... ................ . ...... . ....... AREA OF STUDY..... ................................ The County as an Areal Unit....................... Kern County's Location and Characteristics........ The Desert Region.. ..... ....................... The Valley Region.............................. The Mountain Region......... ........ .... ....... Vegetation........ ........... ....... ........ Cattle Ranching... ......... ............ ........ METHODOLOGY..... ........... ....... ......... . ...... Instrument Design... ......... . .......... .......... Sampling.......................................... The Interview.. ...... ............................. Data Compilation ................ . ........ ......... Ranch Classification.. ...... . ........... .. ..... Ranch Size.. ............ .............. ..... Length of Operation......................... Type of Ownership/Operator.................. Compilation of Topic Responses................. Mapping of Data.. ....... ...... ................. Data Interpretation ............................... RESULTSOOOO OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO FOOd supp1YOOOOO ..... OOOOOOOOOOOOOOO. 0000000000000 Past ReseaIChOOOOOOOOOOOIOOOOOOOOOOOO00.0.00... Kern County Livestock Production... ....... ..... iii l7 17 21 24 24 27 28 30 33 33 35 39 40 40 41 43 44 44 48 49 49 49 SO CHAPTER Page Stocker Cattle Vs. Cow-Calf Ranching Operations......................... ....... 53 Removal of Livestock Carcasses............... 56 Livestock Mortality........ .................. 58 Seasonality of Food Supplies.... ...... . ...... 62 Fire Suppression............................. 66 Depradatory Mammal Control...................... 67 Accidental Poisoning of Condors.............. 67 Ground Squirrel Control in Kern County....... 68 Rodenticides Used in Kern County............. 69 Compound 1080, Zinc Phosphide, and Condors................................ 72 Kangaroo Rats in Kern County. ..... ........... 73 Predator Problems and Control Methods. ....... 74 Predator Control and the Condor........... 77 Depradatory Mammal Control -— Summary........ 78 Shooting and the California Condor......... ..... 78 PastIncidentsand Studies.................... 78 Hunting on Kern County Ranches............... 80 Poaching and Vandal Shooting............ ..... 83 The California Land Conservation Act ............ 87 Rangeland Conversion and Habitat Loss........ 87 The Williamson Act...................... ..... 89 Kern County Condor Habitat and the Williamson Act................ ..... ....... 90 Rancher Participation in the Williamson Act.. 94 The Effectiveness of the CLCA as a Tool for Habitat Preservation.............. ..... 96 Public Lands........................... ......... 97 History of Grazing on Public Lands.... ....... 97 Public Land Grazing in Kern County.. ......... 98 V. CONCLUSIONS, DISCUSSION AND RECOMMENDATIONS..... 101 Conclusions....................... ....... ....... 101 Discussion................................. ..... 105 Recommendations for Future Studies..... ...... ... 109 APPENDICES Appendix A The Rancher Questionnaire.......... .......... 112 Appendix B Ranch Categories and Compiled Responses for Chi-Square Tests...................... 116 Appendix C Chi-Square Tests for Ho3a-e and Ho4a-c ....... 120 iv Table 1. LIST OF TABLES Kern County Livestock Numbers........ Type of Cattle Grazed on Kern County Ranches ......... . ...... ..... ...... Causes of Livestock Mortality........ Methods Used by Ranchers to Control Ground Squirrels.... ..... . ........ Predator Control Methods Used by Kern County Ranchers......... ..... Illegal Shooting Problems on Kern County Ranches ........... . ........ Kern County Rangeland ................ Page 51 55 60 70 77 84 88 LIST OF FIGURES Figure Page 1. Present Range of the California Condor. ...... 3 2. Location of the Condor Range in Kern County.. 18 3. California Condor Critical Habitat........... 20 4. Annual Precipitation in Kern County .......... 23 5. Physical Regions of Kern County.............. 25 6. Location of Kern County Ranches as Drawn by Ranch Operators. ................. . ..... 45 7. Approximate Size and Location of Ranches Studied in Kern County.................... 47 8. Kern County Cattle and Calves ......... . ...... 52 9. Kern County Sheep and Lambs ............ ...... 52 10. Kern County Calving................... ....... 65 11. Kangaroo Rats on Kern County Ranches ......... 75 12. Agricultural Preserve Contracts in Kern county.........OOOOOOOOOOOOOO......OOOOOOO 92 13. Public Land in Kern County... ...... . ......... 93 14. Williamson Act Contracts on Kern County RanCheSOOOOOOOOOOOO......OOOOOOOOOOOOOO0.0 95 vi CHAPTER 1 INTRODUCTION Context of the Problem The California Condor, a federally listed endangered species, is dependent upon southern California's livestock ranches for most of its food and feeding habitat. Land man- agement activities and land use changes which occur on ranches within the condors' range may significantly affect the welfare of these birds. This study investigates selec- ted management activities on cattle ranches in Kern County, California and discusses the relationship between these activities and the quality or quantity of the condors' feed- ing habitat. Population Size and Distribution Only in the mountains and foothill regions of southern California is one now able to find North America's largest land bird, the California condor (Gymnogyps californianus). The approximately twenty condors remaining in the wild (Snyder 1982, p.6) represent a population which has been steadily declining and is now in grave danger of disappear- ing altogether. In the past when condors were much more numerous, their range extended from as far north as British Columbia, Canada to Baja California, Mexico on the south. Today the range is much reduced, including portions of only six counties in southern California. This wishbone shaped area extends from San Luis Obispo and Tulare Counties south- ward to Ventura and Los Angeles Countiesl (Figure 1). Within this range, the areas most often frequented by the condor are the rugged mountains and their adjacent foothills and rolling grasslands. By the turn of the century it was well known that the population and range of the California condor had been and were continuing to decrease in size (Stewart 1908, p. 130, Verner 1978, p. 22), but it was not until the late 1930's that significant research and protective actions were begun. In 1937, the 0.5. Forest Service established the 1,198 acre (485 ha.) Sisquoc Condor Sanctuary in Santa Barbara County. A decade later, the Sespe Condor Sanctuary was established in the Los Padres National Forest in Ventura County. This sanctuary originally contained 3,458,000 acres (14,000 ha.) but in 1951 it was expanded to 5,298,150 acres (21,450 ha.). Condors were further protected in 1953 when the State of California made it illegal to kill or capture any condor at any time (Section 1179.5 of the California Fish and Game Code). The first major study of the California condor was undertaken by Carl Koford in 1939. Koford's report on the life history and ecology of the condor (1953) still stands out as the most comprehensive and in-depth study of this 1Recent and fairly reliable condor sightings indicate that birds may occasionally visit areas further north along California's Coastal Range including portions of Monterey and, possibly, Santa Cruz Counties. \ 3 / \‘ Santa Clara\‘-\/ ’ .' Santa Cruz\~ ‘ ‘ .:.-.';.._ . ... \ I~"‘(¢ . 21-";2 3'33}, 1" \ ‘ ’ \ ~\’/ \-~/-/ "_--P-— K . ‘\ J l—- Merced 4/ JJ ’ \ '_J Kenn \ ,4 r \ ‘\ .5 I.-.’ 1' .r/‘sv ' - J y \ Tulare\ l Monterey '\ -—-—-_-_-\_-___L-__ __/____ \ 4n Luis Obispo \ (“I/”\n \'— —J I» ' 7" ‘ ' N .. L--—-—- -— . Santa Barbara ' \ / \ l . . .1 .: ' Los Angeles 0 24 8 ms ' ' . ' 31"" \_ I Ventura \)/ o 40 km Nevada Present Range of the California Condor Figure 1 map area .. 4 bird ever published. Further studies such as those by Miller et a1. (1965), Sibley (1969), and Wilbur (1972 and 1978), provided additional information on the condor and its problems and subsequently helped to form the limited fund of knowledge upon which past and present condor recovery programs have been based. Condor Recovery Programs and Problems According to the federal Endangered Species Act of 1973, a recovery team must be established to draft a recov- ery plan for each endangered species in the United States. The California Condor Recovery Team, composed of members from the 0.8. Fish and Wildlife Service, the 0.8. Forest Service, the California Department of Fish and Game, the National Audubon Society, and the 0.5. Bureau of Land Management, was one of the first teams organized. Offici- ally approved in 1975, the California Condor Recovery Plan outlines the measures necessary to save the condor from extinction. The goal of the recovery plan is to bring the species to a non-endangered status. By the time the plan was adopted many of the recommended measures had already been initiated or completed, however, the condor population still had not stabilized (Wilbur 1976, p. 47). In September 1979, the same five agencies that drafted the recovery plan jointly signed the Cooperative California Condor Conservation Program thereby creating the Condor Research Center (CRC). Located in Ventura, California, the CRC conducts field research on the condor's problems and 5 assists in management programs designed to maintain the condor p0pulation and retain suitable habitat. Despite the research and management programs which have already been conducted, far too little is known about the condor, its requirements for survival, and its current eco- logical problems. Researchers and others concerned with the welfare of the condor frequently disagree on issues such as why the species is declining and which methods, if any, should be employed to help save the bird from extinction. A wide variety of reasons for the decrease in condor numbers has been suggested. Among those factors most res- ponsible for the condor pepulation decline before and during the early 1900's are the following: egg collecting,shooting, inadvertent trapping and poisoning, and the loss of habitat through the encroachment of civilization. The most fre- quently suggested and the most probable reasons for the birds' continued decline include inadvertent poisoning from attempts to control pest mammals, shooting, food shortages, low reproductive rates caused by pesticides and nest disturb- ance and loss of habitat resulting from land use conversions and the increased disturbance of natural settings by human intrusions into previously remote areas. To date there has not been sufficient evidence to establish any of these factors as the primary reason for the continued downward trend in the population. Although the condors' range is now but a fraction of its original size, the amount of land included is still very 6 large and diverse. A wide variety of land-cover/land—use2 types occur within the condors' range. Some areas are re- mote and rugged remaining very much in their natural state while others have been greatly modified by human activities. Research efforts geared towards understanding and clearly identifying the condors' problems are severely hampered by these areal changes, magnitudes, and diversities. The land uses and activites which occur within the condors' range are regulated by various levels of government including local, county, state, and federal governmenttudts. Each unit has jurisdiction over certain specified land areas and can regulate certain land use activities. Local and county governments can regulate only those activities that occur within their boundaries and which are not already regulated by the state or federal governments (although they can in some instances enforce stricter regulations ontactivi- ties which are already regulated by the state or federal governments). Often the county has the responsibility of seeing that certain state regulations or programs are en- forced or implemented. Sometimes the county is permitted some degree of latitude in the implementation of these state programs. This array of government units, each with varying jurisdictions and duties adds further complexity to the 2Land cover is simply the surface cover found on the specified land area (forest, grassland, water etc.). Land use identifies the actual human use of the area (mining, housing, crOpland, etc.). 7 condors' range as one unit may be subject to different environmental regulations than other units. The Importance of Land Use and Management Many of the previously mentioned reasons for the cond- ors' decline are directly or indirectly associated with land use and land management practices.' The condor makes use of both public and private lands but the control of land uses on these two types of lands differs greatly. On public lands,3 the general public can have a voice in deciding how these lands are to be used and managed as long as the desired uses are not in conflict with the stated' purposes and objectives of the land conservation system of which the land parcel is a part. Condor habitat situated within public lands can be managed so as to preserve import- ant habitat qualities if the agency involved has the mandate to do so and has the necessary political and public support. Most of these public land areas have very stringent land use regulations which, when enforced, result in the preservation of land which is frequently less disturbed or developed than the surrounding privately owned properties. The inclusion of land within the federal land conservation systems has greatly benefited the condor in that important habitat has been preserved. This is especially true for most of the 3The public lands which are of most importance to the condor include national forest lands administered by the 0.5. Forest Service and national resource lands administered by the Bureau of Land Management. 8 condors' nesting and roosting sites. Unfortunately, most of the condors' feeding habitat is not so preserved. The California condor is a scavenger, feeding only on dead animals. The feeding habitat of the condor consists primarily of the rolling grasslands and oak—studded savannas characteristic of the foothills of the Coast, Transverse, and Sierra Nevada ranges. These grasslands are predomin- antly used for livestock grazing on privately owned ranches. Beef cattle are the main livestock but sheep are also grazed. Livestock losses from these ranching Operations provide the primary food source of the condor. The continu- ation of the use of the grasslands situated within the cond- ors' range for livestock production is, therefore, vitally important to the survival of the condor. Within certain limits, private landowners are free to use their land as they desire. This means that if ranch owners are able to convert their lands to more profitable activities such as irrigated agriculture or residential housing, they may decide to do so thereby removing such parcels from the supply of feeding habitat available to the condor. Similarly, if for some reason it becomes unprofit- able or impossible for ranchers to remain in business, they may be forced to sell their properties to someone who may have no desire to retain ranches in their current use. Consequently, anything that adversely affects the southern California livestock industry could eventually have an adverse effect on the condor. Some ranch management activities could also be of great importance to the condor and its ability to survive. For instance, ranchers may choose to undertake pest rodent con- trol programs that will make their ranches more productive or better suited to the livestock being raised. Activities such as this may directly or indirectly affect the condor. However, such activities may be either beneficial or detri- mental to the condor or may have no effect whatsoever on the bird. It is important to know what activities are currently taking place on ranches within the condors' range and to identify activities that may have an effect on the species' survival. To minimize the possibility of condor mortality within its feeding habitat, areas that may pose possible or extraordinary threats to the condor should be located and investigated. It is also important to identify problems that could have a negative impact on the livestock industry or which may cause a rancher to sell his ranch thereby affecting the management or quality of feeding habitat. Problem Statement In order to effectively manage a condor recovery pro- gram, more information about the private lands located with- in the condors' range must be acquired. Much headway has been made in preserving public land and in restricting human activities on these areas for the benefit of the condor. However, condors depend on privately owned rangeland for 10 most Of their feeding habitat and food supply. Recovery efforts must provide some methods Of securing safe and sufficient habitat outside Of the federal preserves. The purpose Of this study was to investigate certain cattle ranch management practices and land use activities which have been identified as having an impact on the California condor and/or its feeding habitat. Some ranch management practices such as administering a poisoning pro— gram for control Of ground squirrels, permitting hunting on private lands, and replacing cow-calf herds with stocker cattle,4 have been suggested as being detrimental to the welfare of the condor. Other activities such as placing ranch land under contract through participation in the Williamson Act5 program and leaving carcasses out on the range, are viewed as being beneficial to the condor. This study sought to determine how widespread these ranch 4Cow—calf operators maintain basic herds of cows which produce calf crops each year. These calves are generally sold after they are weaned at weights of approximately 400- 500 lbs. (Mortimer 1980, p. l). Stocker cattle Operators ship in steers from other areas (generally from other states and/or Mexico) and graze them on their ranches for only a portion of the year (when range conditions are best). Con- sequently, stocker cattle ranching is a seasonal Operation with high concentrations of cattle on the range during grazing periods and little or no cattle present during the off season after the steers have been fattened and sold (Miller et a1. 1965, p. 21). 5The Williamson Act (State of California Government Code Sections 51200-51295) provides for differential assessment of agricultural lands so that land owners who restrict the legally permissable land use on their prOper- ties to agricultural crop or livestock production only enjoy a tax benefit over other lands that are not so restricted. 11 activities have been and to identify any areal variations in their existence or impact. Although basic methods of livestock ranching will remain fairly constant from one ranch to another, there may be variations among the ranches in their approaches to several management issues. A secondary purpose Of this study was to determine whether certain types of ranches were more likely to pursue management activities beneficial or detrimental to condors than others. The results of this study provided information which can be used to more clearly identify problem issues and situations which affect feeding habitat preservation and quality, provided inform- ation on possible causes of condor mortality, and located areas where potential hazards to the condor may exist. Goals of the Study The goals of this study included the following: 1. to determine how prevalent certain ranch activi- ties identified as affecting the California Condor Or its habitat are throughout the condors' Kern County range; 2. to locate any areal concentrations Of these ranch activities; and 3. to determine whether certain types of ranches are more likely to be Operated by using management activities which may be detrimental to condors. 12 Hypotheses The condors' reliance on the continuation Of the tradi- tional livestock ranching industry within its range provides the major premise on which the basic hypothesis Of this thesis was formulated. This basic hypothesis is as follows: Land uses and management activities on cattle ranches in Kern County, California have an effect on the quality Of the California condors' feeding habitat and hence on this endangered species ability to survive. Five sub-hypotheses were developed from this general hypothesis, namely: 1. The amount of food available to the California condor is affected by livestock management activities prac- ticed on Kern County cattle ranches. This was investi- gated by testing the following null hypotheses: a. The amount of livestock (both cattle and sheep) produced annually in Kern County has not, during the past twenty years, declined to the point where the condors' food supply is affected. The number of Kern County ranches engaged in stocker cattle production has not significantly reduced the condors' food supply. Disposal methods used for livestock carcasses on Kern County ranches have not reduced the condors' food supply. The incidence and type of livestock mortality on Kern County cattle ranches have not reduced the 13 condors' food supply during the past twenty years. e. The seasonality Of calving on Kern County ranches has no influence on the condors' food supply. PrOgrams designed to control problem predators and pest rodents on Kern County cattle ranches create hazardous feeding conditions for the California condor. Shooting for hunting, poaching, and vandalism purposes is common on Kern County cattle ranches and creates a hazardous feeding environment for the California condor. Some kinds Of ranches, are more likely to have a higher incidence Of any of the above three shooting activities. This was investigated by testing the following null hypotheses: a. Size of ranch has no influence on whether hunting by authorized private parties is permitted on the ranch. b. Length Of time the ranch has been in Operation has no influence on whether hunting by authorized private parties is permitted on the ranch. c. Ranch ownership/operator type has no influence on whether hunting by authorized private parties is permitted on the ranch. d. Ranch size has no influence on whether or not wanton shooting is a problem on the ranch. e. Ranch size has no influence on whether or not poaching is a problem on the ranch. l4 4. The loss Of grazing land to other land uses has reduced the amount of land available to the California condor for feeding habitat. Within Kern County, rancher participation in the Williamson Act has helped retain land in livestock production. Some ranches are more likely to participate in the Williamson Act pro- gram. This was investigated by testing the following null hypotheses: a. Ranch ownership/operator type has no influence on whether the ranch land is contracted under the Williamson Act. b. Ranch size has no influence on whether the ranch land is contracted under the Williamson Act. c. Length of operation has no influence on whether the ranch land is contracted under the Williamson Act. 5. The current grazing permit systems used on Kern Countyks Bureau of Land Management and national forest lands benefits the California condor by aiding Kern County cattle ranchers. Related Research Very little research has specifically addressed the relationship between the human use Of rangeland and the quality or quantity Of the California condors' feeding habi— tat. Some authors have briefly addressed the tOpics which are analyzed in this study. Most notable are the works of 15 Koford (1953) and Miller et a1. (1965). Both reports discuss shooting, poisoning, inadequate food supplies, and loss Of habitat from land use conversions as factors in the condors' decline, but neither attempted to document the degree to which these activities occur on ranches within the condors' range. Their studies were, however, most helpful in deter- mining which ranch activities should be included in my research. I have exPanded upon the ideas expressed by Koford and Miller and systematically analyzed their validity within a portion Of the condors' range. Condor habitat loss has attracted slightly more atten- tion than other factors which have been attributed to the condors' decline. One study reviews the loss of condor habitat to land development in Kern County (Buntin 1975). The author discusses land use changes and the potential for future habitat loss in areas of the county which have been identified as being or having been important to the condor. Because Buntin's study focused on Specific development pro- jects it provided very little background information for my research. Although no one has investigated the use of rangeland and its relationship to condor feeding habitat, many have:studied the relationship between agricultural practices and other wild- life species (Bode 1939, Leedy and Daniels 1947, Anderson 1949, Allen 1952, Shrubb 1980). These studies proved to be of little value to my research because they emphasized the biological responses to physical changes in the land cover 16 (species diversity, species density, reproductive success, etc.). Particular attention was given to the species' response to vegetation changes. The destruction Of wildlife habitat from land use changes has been the focus of some research (Gerstung 1973, Vogl 1976, Reynolds 1980, Hurst et a1. 1980, Gorenzel et a1. 1981). Again, the relevance of these works to my research was limited to the acknowledgement of the fact that changes in the physical use of the land are resulting in the loss Of wildlife habitat. The role of private land management in preserving wild- life habitat and in enhancing its quality has been recognized (Allen 1952, National Academy of Sciences 1970, Deknatel 1979, Svoboda 1980). These authors also emphasize the value Of enhancing the quality Of the land cover. In summary, most research on land use and wildlife has been focused on preserving or enhancing the physical charac- teristics of the land which make it most suitable as habitat for game species. Information on the relationships between human activities and wildlife is limited but the need for research on the socio-economic aspects of wildlife management has been recognized (Allen 1952, Hendee and Schoenfeld 1973). CHAPTER II AREA OF STUDY The County as an Areal Unit Of Study Because it would be very costly and time consuming to gather data on ranches throughout the condor range, the study area was limited tO a single county, Kern County (Figure 2). A single county was chosen as the study area because many agricultural programs such as pest control and the administration Of the agricultural preserve system are carried out at the county level and therefore, vary from county to county. Had a larger study area, or one based on a different areal unit, been chosen, it would have been difficult, if not impossible, to make comparisons among the ranches as some would be subject to different regulations and/or have different Opportunities available to them. Focusing on a single county minimized jurisdictional com— plexities, facilitated data gathering, and reduced the vari- ation within the sample by ensuring that all ranchers had the same programs available to them and were governed by the same laws. The county unit did, however, provide a large enough land area to ensure that a sufficient number of ranches could be studied. Kern County was chosen for a number of reasons. First and foremost, much important feeding habitat is situated within this county. It is centrally located within the 17 18 N muswflm .k~.a .Nka .mweuowwamo .eamwwmnmxmm .cOfimmHEEoo wcflccmam .3550 FEM _, O l l O l l ! 3:85me cowumammaoo cam mommm cog "mounom «93: .2230 258:3 IOIOIOIOI _ O _ _ _ . .Hameumsme _ _ _ vaoammumxmm 1. _ _ . .cum muwsmuu O ... _ ....N _ ..u a: 333 OHHHZEOHU , _ N 383 . , . 0' lo lllllllll ole'o'olole o'e'olo'e o'ellro'o 0 0 0'. 0 0L <_Z¢Ou:._<0 .EZDOU ZCmX 19 condors' range and is frequented by them on a year round basis. More than 350,000 acres (about 141,700 ha.) of land in southern and eastern Kern County are regularly used by the condor while portions of another important foraging region are located along the county's western border. (California Condor Recovery Team 1980, p. 3). Southern Kern County provides important feeding habitat for birds nesting in northern Ventura and Los Angeles Counties and is used regularly for feeding and roosting by all condors during the fall months. Portions of northern Kern County may provide important winter habitat for immature birds and other non-breeders. The county's importance to the condor is confirmed by the fact that two critical habitat areas and a portion Of a third are situated within its borders (Figure 3). Aside from its importance as condor foraging grounds, Kern County has other attributes which make it ideally suited for this study. Most of the land used by the condor in this county is privately owned and is used for livestock production. This large supply of private ranchland is situ- atedvdihin three foothill regions, the Temblor Range and the foothills of the Tehachapi and Sierra Nevada ranges. AREA ENLARGED 20 CALIFORNIA CONDOR CRITICAL HABITAT C9) SAN-,Luu O BIS ro \ I (1) (2) (3) (4) (5) (6) (7) (8) (9) I I SCALE IN MILES J KEY , Sespe-Piru Condor Area Matilija Condor Area Sisquoc-San Rafael Condor Area Hi Mountain-Beartrap Condor Areas Mt. Pinos Condor Area Blue Ridge Condor Area Tejon Ranch Kern County Rangelands Tulare County Rangelands Source: California Condor Recovery Plan. California Condor Recovery Team. U.S. Fish and Wildlife Service, 1980, p. 60. Figure 3 21 This topographic variety makes it possible to study ranches associated with two of the three mountain ranges used by the condor.6 Kern County's Location and Characteristics Kern County, California is an inland county situated at the southern end of the San Joaquin Valley. Agriculture, both crOp and livestock production, is the primary economic activity of the county although petroleum extraction is also important. The total land area of the county is 8,152 square miles (21,049.2 sq. km.). Of this total, 5,780 square miles (14,974.l sq. km.) are devoted to agriculture (California State Office Of Planning'and Research 1981, p. 3). Range acreage accounts for 3,437.5 square miles or approximately 42% of the county's land area. This extensive range resource supports a livestock industry which consistently ranks among Kern County's top ten most valuable crops. In 1980, Kern County had a total pOpulation of 403,089 people, an increase of 22.1% from 1970 (Kern CO. Planning Dept. 1981a, p. 1). This growth (approximately 2% per year) 6The condors' range includes portions Of the Coast, Transverse and Sierra Nevada ranges. In this study, the Coast Range is represented by the Temblor Mountains. The Tehachapi Mountains are actually a part of the Sierra Nevada range. The Transverse Range is considered by some to also be represented in a portion of southern Kern County situated within the Los Padres National Forest. Kern County's moun- tain regions will be discussed later in this chapter. 22 is expected to continue (Kern CO. Planning Dept. 1981b, p. I-l). Most Of Kern County's pOpulation is located in the level lands Of the San Joaquin Valley, especially in and around the city of Bakersfield. With a 1980 population of 105,611, Bakersfield is by far the county's largest city. Delano, the second largest town, is quite small.ix:comparison with a pOpulation of only 16,491 people (Kern Co. Planning Dept., POpulation... 1981, p. 7). During the past two decades most of the population growth has been in the Bakers- field and Lake Isabella areas. The physical environment Of the county is quite diverse. Elevation ranges from under 500 feet (152.4 meters) in the San Joaquin Valley (central and north central Kern County) to over 7,000 feet (2,134.1 meters) in the mountain ranges bordering the southern and eastern sides of the valley. Precipitation (primarily rainfall although snow does occur at higher elevations) is strictly a phenomenon of the winter season which generally lasts from November to May. Annual precipitation ranges from six to thirty inches and is strongly influenced by the various mountain ranges. Rain- fall is highest in the Sierra Nevada and Tehachapi mountain ranges and lowest in the Central Valley and the Mojave Desert, both being located on the leeward side Of mountain ranges (Fugure 4). Summers are generally hot and winters warm and mild. Again, temperature will vary with altitude. Kern County can be divided into three general regions based primarily on topographic and climatic characteristics. 23 m K . L .thmxww . Amazon: :3 >FZDOU ZEN! 7: ZO_._.<._._n:UwEn_ JFZDOU Zva. “.0 mZO_UwE .._IQ 26 depicted in Figure 5, the valley region includes all Of the southern San Joaquin below 1,000 feet in elevation (304.9 meters): however, most Of the land is less than 500 feet (152.4 meters). The terrain is mostly very flat but becomes hilly along its borders as the mountain ranges which sur- round it on three sides are approached. On the west side Of the valley is the Temblor Range and on the east are the Sierra Nevada Ranges. The Coast Ranges, a small portion of the Transverse Ranges, and the Tehachapi Mountains converge to form the valley's southern border. In its pristine condition, the valley region was an ex- tensive natural grassland community (Burcham 1957, pp. 66,90). As such it was an improtant part Of the rangeland resource. Perennial bunchgrasses dominated the vegetation. Among these, the most important were purple needlegrass (Stipa pulchra) and nodding needlegrass (Stipa cernua) along with blue wild- rye, pine bluegrass, and deergrass (Burcham 1957, p. 90). Most of the valley region is now devoted to intensive irrigated agriculture. This agricultural production was not possible until after the completion of the Central Valley Project and the Wheeler Ridge/MariCOpa portion of the California Aqueduct (a portion of the State Water Project) which provided inexpensive water for the valley farmers (Wilcock, et a1. 1976; Mason 1973). Where cattle and sheep once grazed, one now sees cotton, grains, orchards, vine- yards, and truck crOps. It is possible that the condor once used these portions Of the Central Valley, but more than 27 likely, the bird kept to the hilly valley edges where range- land conversion has not been as great and condors are still sighted (Koford 1953, p. 69; Stewart 1908, p. 130). The Mountain Region The mountain region occupies the western margin of Kern County as well as a large central area situated between the Central Valley and the Mojave Desert (Figure 5). Elevations in these highlands range from about 1,000 feet (304.9 meters) to over 8,000 feet (2,439 meters). Because most condor habi- tat is also located above 1,000 feet (Wilbur 1978, p. 7), this region is the most important to the species and hence is the focus of this study. Along the western border of Kern County are the moun- tains which make up the northwest-southeast trending Temblor Range. These relatively low mountains (elevations seldom exceed 4,000 feet) form one of the most easterly'ranges of the California Coast Range Province. Precipitation is scant because the Temblors are interior mountains lying to the east Of other ranges. Much of central Kern County is occupied by the Sierra Nevada ranges and their foothills. These fault-block moun- tains are the highest in the county and form a barrier to moisture bearing westerly winds. Consequently, the western slopes of the Sierra Nevada receive a greater amount of precipitation than any other area Of the county. Along the county's southern border directly east of Interstate 5, are located the Tehachapi Mountains, the southern terminus of 28 the Sierra Nevada. Here the slightly east-of—south trend Of the Sierra Nevada changes to west-of—south. The Tehachapi Mountains terminate at Tejon Pass (the present route for Interstate 5) where they are joined by both the southern extension of the Coastal Ranges and the northern edge Of the Transverse Ranges. Most Of southern Kern County east of Interstate 5 is an extensive foothill region called the Pleito Hills. As one continues southward into these foothills, the terrairlbecomes increasingly rugged and eventually the northern most physio- graphic unit Of the Transverse Ranges, the Pine Mountain-- Frazier Mountain Interior Ranges, is reached (Durrenberger 1959, p. 21). Vegetation: The type of vegetation found on the moun- tains and foothills Of Kern County is primarily dictated by the altitude and the amount Of rainfall received. As one travels away from the Central Valley toward any of the county's mountain ranges, the once extensive California grass- lands become more conspicuous and widespread. 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