Formula Grant F24AF02486

MULE DEER IN EASTERN OREGON HAVE EXPERIENCED LONG-TERM POPULATION DECLINES AND THESE DECLINES ARE NOT RESTRICTEDTO A SINGLE GEOGRAPHIC REGION. BASED ON CHRONICALLY LOW RECRUITMENT OF FAWNS INTO THE ADULT POPULATION,NUTRITION, PARTICULARLY ON SUMMER RANGE MAY BE A FACTOR CONTRIBUTING TO LOW RECRUITMENT AND POPULATION DECLINES.IN MANY UNGULATE SPECIES, ANNUAL VARIATION IN RECRUITMENT IS THE PRIMARY DETERMINANT OF POPULATION GROWTH GIVENADULT SURVIVAL TENDS TO BE RELATIVELY HIGH AND INVARIABLE. IN MULE DEER, RECRUITMENT IS THE PRODUCT OF THREEVITAL RATES: PREGNANCY, FETAL RATE, AND SURVIVAL OF OFFSPRING TO ONE YEAR. NUTRITIONAL CONDITION OF FEMALE MULEDEER SHOULD HAVE A STRONG EFFECT ON REPRODUCTIVE PERFORMANCE AND SURVIVAL OF OFFSPRING IF NUTRITIONAL RESOURCESARE LIMITED ON THE LANDSCAPE. THE QUANTITY AND QUALITY OF FORAGE ON SUMMER RANGE WILL AFFECT NUTRITIONALCONDITION OF FEMALES ENTERING WINTER, WHICH IN TURN WILL AFFECT OTHER VITAL RATES INCLUDING: 1) PREGNANCY RATES,2) FETAL RATES, 3) NEONATE BIRTH MASS AND GROWTH RATES, 4) JUVENILE SURVIVAL AND RECRUITMENT, AND 5) FINALLYADULT SURVIVAL. AS THE SEVERITY OF NUTRITIONAL LIMITATION INCREASES, IT WOULD BE EXPECTED THAT VITAL RATESAFFECTING OFFSPRING WOULD DECLINE FIRST, AS THE MATERNAL FEMALE WILL USE NUTRITIONAL RESOURCES TO ENSURE SURVIVALTO THE NEXT YEAR WHEN CONDITIONS MAY BE BETTER (E.G., A BET-HEDGING STRATEGY OF REPRODUCTION). GIVEN THISREPRODUCTIVE STRATEGY, TO EFFECTIVELY STUDY POTENTIAL NUTRITIONAL LIMITATIONS IN A POPULATION IT IS IMPORTANT TOASSESS THOSE FACTORS WHICH ARE MOST LIKELY TO BE AFFECTED BY NUTRITIONAL LIMITATIONS (E.G., PREGNANCY RATES,FETAL RATES, AND FAWN SURVIVAL).THIS RESEARCH PROJECT IS DESIGNED TO ASSESS THE ROLE OF SUMMER NUTRITION ON MULE DEER POPULATION PERFORMANCE INEASTERN OREGON. TO CONDUCT THIS RESEARCH, WE WILL CAPTURE ADULT MULE DEER IN LATE FALL (DECEMBER) TO MEASURETHEIR BODY FAT AND ASSES THEIR PREGNANCY STATUS. WE WILL RECAPTURE DEER IN LATE WINTER (MARCH) TO AGAIN MEASUREBODY FAT, ASSESS PREGNANCY STATUS, AND NUMBER OF FETUSES. ADULT FEMALE MULE DEER WILL BE FITTED WITH A GPS COLLARAND PREGNANT FEMALES WILL BE FITTED A VAGINAL IMPLANT TRANSMITTER TO AID IN CAPTURE OF THEIR FAWNS THE FOLLOWINGSPRING. FAWNS WILL BE CAPTURED AFTER BIRTH AND FITTED WITH COLLARS TO MONITOR SURVIVAL THEIR SURVIVAL ANDDOCUMENT THE CAUSE OF MORTALITY. WE WILL ALSO CAPTURE 6-MONTH-OLD FAWNS ENTERING WINTER TO OBTAIN THEIR WEIGHT DURING YEARS OF INCREASED NUTRITIONAL STRESS, FAWNS SHOULD HAVE REDUCED GROWTH RATES AND BE SMALLER ENTERINGWINTER. THESE FIELD APPROACHES WILL ALLOW US TO COMPLETE THE FOLLOWING OBJECTIVES:1. ASSESS NUTRITIONAL CONDITION OF ADULT FEMALES ENTERING AND LEAVING WINTER AND DETERMINE IF BODY FAT LEVELS ARESUFFICIENT TO SUPPORT POPULATION GROWTH.2. DETERMINE THE RELATIONSHIP BETWEEN MATERNAL CONDITION (I.E., BODY FAT) AND PREGNANCY RATES, FETAL RATES, ANDFAWN AND DOE SURVIVAL.3. DETERMINE THE RELATIONSHIP BETWEEN FAWN WEIGHTS ENTERING WINTER AND ENVIRONMENTAL CONDITIONS.4. DETERMINE HOW HABITAT USE AND OTHER ENVIRONMENTAL CONDITIONS (E.G., DROUGHT) AFFECT NUTRITIONAL CONDITION OFADULT FEMALE MULE DEER ENTERING WINTER.IDENTIFYING THE DEGREE OF NUTRITIONAL LIMITATIONS IN MULE DEER POPULATIONS IN OREGON IS CRITICAL FOR EFFECTIVEMANAGEMENT OF THE SPECIES. THIS WORK WILL IDENTIFY FACTORS LIMITING POPULATION GROWTH IN MULE DEER. THESEFINDINGS WILL ALLOW WILDLIFE AND LAND MANAGERS TO DEVELOP STRATEGIES TO IMPROVE NUTRITIONAL CONDITIONS FOR MULEDEER. INCREASING MULE DEER POPULATIONS WILL ALLOWED FOR INCREASED RECREATIONAL OPPORTUNITY AND ECONOMIC BENEFITSIN OREGON.