SNOWCREEKSKI AREA DEERSTUDY 1994SPRING AND FALL MIGRATION STUDY heparedfor: DempseyConstruction C orporation P.O.Box 657 MammothLakes, CA 93546 6191934-6,861 hepared by: TimothyTaylor & Associates P.O.Box l9l JuneLake, CA93529 619t648-7227 I\,larch1995 Tableof Contents Page Chapterl. Introductionand Methods.... .............l-l INTRODUCTTON..... ...........l-l PERMITAREA...... 1.2 METHODS....,.......... ............r-2 RadioTelemetry Studies...... ........L-2 RadioTracking ofDeer...... ..................l-2 HoldineArea Studies.............. .....14 D-eerCounts Surveys... ........14 tlabitatUse Studies................ ..............l-6 MigrationCorridor Counts...... .....1-7 InfraredSensor Equipment ...................l-7 HabitatMapping... .....l-7 WeatherData.......... ....1-7 ORGANIZATIONOF THISREPORT.. ..................l-8 Chapter2. SpringMigration Surveys..... .............2-l STAGE 1: MIGRATION BETWEEN THE WINTER RA}.IGE IN ROUNDVALLEY A}ID TI{E SFIERWINHOLDING AREA....... ........... 2.1 Locationsof DeerMovements................ ......2-l STAGE2: TIIE SHERWINHOLDING AREA....... .................2-3 Timing andIntensity of DeerUse in the SherwinHolding Area.......2-3 Radio-CollaredDeer.. ........2-3 DeerCount Surveys..... .......2-5 Estimatesof DeerAbundance in theSherwin Holding Area.............2-10 Patternsof DeerHabitat Use in theSherwin Holding Area.......... ....2-14 DeerCount Surveys..... .......2-14 Radio-CollaredDeer.. .........2-19 Patternsof DeerDistribution in the SherwinHolding Area.......... ....2-19 STAGE 3: DEER MIGRATION BETWEEN T}IE SHERWIN IITOLDINGAREA AI{D TI{E SUMMERRA}.IGE.... ...............2.22 MigrationRoutesOvertheSierraCrest......... .................2-22 MigrationRoutes Over the Sierra Crest-spring 1994.......................2-23 MigrationThroughtheSSAPermitArea.......... ..2-23 Migration Over SanJoaquin Ridge Hopkins Passand PiutePass. ...... 2-23 Summaryof DeerMgration Over the SierraCrest......... ......2-23 Timing and Intensityof Migration throughthe Snowcreek Ski Area... 2-24 RemoteDeer Counterc............. ............2-24 Verificationof DeerCounter Accuracy... ...............2-26 DailyTiming ofDeer Movements .........2-27 I SummerRanges of Radio4ollaredDeer.......... ..............2-27 RoadKill Data.......... ..2-29 Chapter3. Fdl MgrationSurveys..... .................3-l MgrationStudies...... .............3-l Timing andIntensity of Mgration Ttrough the Snowcreek SkiArea.... ..................3-l Radio-CollaredDeer.. ......3-l RemoteDeer Counterc............. .........3-l Verificationof DeerCounter Accuracr'... ............3-l DaityTiming ofDeer Movements..................:.................................34 DeerComposition Counts...... ................3-4 RoadKill Data:........ ............34 Chapter4. Conclusionsand Recommendations........ .............4-l Chapter5. Acknowledgments.. ...........5-l Chaper6.Citations ...........6-l Appe'ndix.. ........A-l Listof Fizures Figure page l-l Locationof theSnowcreek Ski Area.... ... l-3 l-2 Locationof theDeer Count Survey Route in the SherwinHolding Area..... l-5 2-l Locationsof RoundValley Deer Herd MigrationRoutes, Mono County, California.. ............2-z 2-Z CumulativePercent of Radio-CollaredDeer Arriving on andDeparting fromthe SherwinHolding during the 1994Spring Migration.. ...24 2'3 Periodof Delayfor IndividualRadio-Collared Deer on the SherwinHolding Areaand the SnowcreekSki Areaduring the 1994Spring Migration.. ........2-6 2'4 CumulativePercent of Radio-CollaredDeer Arriving on andDeparting from the SnowcreekSki Areaduring the 1994Spring Migration.. ......2-7 2-5 Total Numberof DeerCounted per Day duringDeer Count Surveys Conductedin theSherwin Holding Areq Spring1993 and 1994.................2-8 2'6 TheTrend in SightingProbability on Group Sizeand the Numberof Deer Countedin the SherwinHolding Area during the 1994Spring Mgration.. ..2-12 Z-7 Percentof DeerObserved by VegetationType on the SherwinHolding Areaduring the 1994Spring Migration.. 2-13 2-8 Locationsof DeerGroups Observed in the SherwinHolding Area duringthe 1993Spring Migration.. ..........2-16 2-9 Locationsof DeerGroups Observed in the SherwinHolding Area duringthe 1994Spring Migration.. ..........2-17 2'10 ConfidenceIntervals (95%) IndicatingMule DeerUse of Habitaton the SherwinHolding Area during the 1994Spring Migration.. .........2-18 2'll Locationsof 237 Observuionsof 27 Radio-CollaredDeer in the Sherwin HoldingArea during the i994 SpringMgration.. ..... 2-20 2-12 Numberof EventsCounted per Day by the Trailma.*erUnits at Solitude Pass,Spring Mgration 1994.......... ..........2-25 lu Listof Figues(cont.) Figure Page 2-13 Timingof Deer Movementsthrough the ProjectArea during Spring Migration1994.......... ............2-28 3-l Percentof Radio-CollaredDeer Crossing the SierraCrest in Relation to DailySnourfall Fall Migration 1994.... ..................3-2 3-2 Numberof EventsCounted.per Day by the TrailmasterUnits at Solitude Pass,Fall Migration 1994.......... ...............3-3 3-3 Timingof Deer Movementsthrough the ProjectArea during Fall Migration1994............... 3-5 AppendixFigure 2............... ..............A-2 AppendixFigure 3............... ...............A-3 Tebles 2-l Meanpopulation estimates and ranges within 95% confidencelimits for muledeer counted on the Sherwinholding area during l0 deercount surveys conductedfrom April 7-June 9, 1994...... ..................2-l I 2-2a Utilization-availabilitydata for dominatehabitat types in the Sherwin holding area"Mammoth Lakes, California. Utilization datais basedon locationsof 160deer groups observed during l0 deercount surveys conductedduring spring 1994.......... ........2-15 2-2b Utilization-availabilitydata for dominatehabitat types in the Shenuin holding are4 MammothLakes, California. Utilization datais basedon locationsof 152deer groups observed during l0 deercount surveys conductedduring spring 1993.......... ........2-15 2-3 Utilization-availabilitydata for dominatehabitat types in the Sherwin Holding Area, MammothLakei California. Utilization datais based on237 visuEllocations of 27 radio-collareddeer observed in the Sherwin HoldingArea duringthe 1994spring migration.. .......2-19 iv 24 Calculatedmule deer home range areas (hectares) for the Sherwinholding areaand the SnowcreekSh fuea usingthe minimumconvex polygon and adaptivekernel methods.... .....2-21 2-5 Percentof radio-collareddeer that useddifferent migration routes over the Sierracrest, based on radiotelemetry data fiom Kucera( 1988)and spring1,994.......... ..................2-23 2-6 Approximatetiming of deermovements through Solitude Canyon andover SolitudePass during the springmigrations of 1985-1989 and1993-1994 (Kucera 1985, Taylor 1988, Taylor 1994)..... .....2-26 2-7 Locationsand habitats of 4 adultfemate mule deer observed in the SherwinSki Area between June 15 and June 30 1994.... ............2-29 2-8 Deerfatalities recorded by Caltransduring spring and summer 1994...........2-30 3-l Numberof deerclassified in the SnowcreekSki Area and surrounding vicinityaccording to sexand age during the 1994fall migration..................3-4 v Chapterl. Introductionand Methods INTRODUCTION In June1994. Dempsey Construction Corporation (DCC) of MammothLakes. California,completed preparation of a DeerHerd Monitoring Plan (DHMP) (Raedeke Associates1994) for the proposedSnowcreek Ski fuea (SSA). TheFinal Environmental ImpactStatement (FEIS) for the SSA specifiedthat the DHMP be developedin orderto assessthe effectivenessof mitigation measuresdesigned to minimizeimpacts of the SSA on migratorymule deer,and to determinethe overalleffect of the SSA developmenton the RoundValley deer herd, formerly known as the SherwinGrade and Buttermilk deer herds. The SSAis locatedimmediately south of the Townof MammothLakes (TML) on approximately3,100 acres of publicland managed by theU.S. Forest Service (USFS). Theproposed ski areaand surrounding vicinity is regardedas importanttransition range for mule deer(Odrcoileus hemiomtshemiomrs) from the Round Valley herd.which migratethrough the areaduring annualspring and fall migrations. Throughoutthe past decade,the CalifomiaDepartment of Fish andGame (CDFG) hasbeen collecting data on the RoundValley deer population with emphasison factors affectingpopulation size and trend and habitatuse relationships. During the sameperiod, DCC hascollected site-specific data on the timingand locations of deeruse panerns in the proposedSSA permit areaand surroundingvicinity. The DHMP was designedto expand on this existinginformation and to furnishdata required by the SSA-FEISfor the analysis of potentialimpacts to migratorymule deer (Raedeke Associates 1994). Thisreport summarizesfield studiescompleted by DCC duringthe 1994spring andfall migrations.Specific objectives of the springwork wereto: l) determine,through the useof radio telemetryand infrared sensorequipment, the amount,timing, andspecific locationsof migratorydeer use in the SSAand surrounding lands during the 1994spring andfall migrations;2) censusthe SherwinHolding Area (SIIA) usingdeer population estimatesbased on mark-recapturetechniques using radio-collared deer; 3) dwelop a *sigbtablity index" to estimatethe numberof deerin the holding areabased on the number of deerobserved during a given census;and a) determinehabitat use patternsby radio- collareddeer that use the SnowcreekSki Area and sunoundinglands. Objectivesof the fall work were to determinethe amountand timing of fall migratory deeruse and the specificlocations of deermigration routes. The informationpresented