Dytime Hbitt Selection by Resident Golden Egles in Southern Idho, USA Environmentl & Sttisticl Consultnts Chd LeBeu 1-04-14 Ryn Nielson, Eric Hllingstd, nd Dve Young cwlebeu@west-inc.com
Introduction Risk estimted from observtionl studies Nest surveys Ground-Bsed observtionl studies Collected under sptil nd logisticl constrints which my over- or under-estimte hbitt use Imprecision ssocited with dt collection due to wether, time of dy, ccess, nd observtion bis Aldridge et l. 008 WEST, Inc.
Introduction Risk estimted using resource selection functions (RSF) Animls use set of resources nd these resources cn be compred to set of vilble resources Utilized for numerous different species Identify res of high use Aldridge et l. 008 WEST, Inc. 3
Study Purpose nd Objectives Study purpose: Anlyze golden egle GPS dt in conjunction with known nesting loctions to estimte hbitt selection Objectives: Inventory golden egle nests nd territories within the study re Generte robust RSFs to predict golden egle hbitt selection cross the study re Demonstrte how predictions of golden egle hbitt selection my be used to delinete high use res or res of potentilly higher risk in lnd mngement plnning Aldridge et l. 008 WEST, Inc. 4
Study Are Southern Idho nd northern Nevd ner the town of Jckpot, Nevd The study re consisted of pproximtely 13,180 h (,13 km ) Centered on the lrge geogrphic fetures of Chin Mountin, Browns Bench, nd Slmon Flls Creek Reservoir Aldridge et l. 008 WEST, Inc. 5
Methods Golden Egle Nest Survey Cpturing Model Development + ( 3.717 elevtion _ men) ( 0.381 nest ) wx ( ) = exp ( 0.115 rdition) + ( 36.034 rugged ) ( 4354.400 rugged ) ( 83.600 brit) ( 441.895 brit ) ( 0.404 nest ) ( 109.367 rugged ) w( x) = exp ( 1759.370 rugged ) ( 0.913 shrub) + ( 0.150 slope) ( 0.00 slope ) ( 0.450 nest ) ( 0.177 lek ) + + w( x) = exp 35.454 brit 530.179 brit + ( ) ( ) ( 75.831 rugged ) ( 517.05 rugged ) ( 0.488 nest ) + ( 57.08 rugged ) w( x) = exp ( 4801.47 rugged ) + ( 16.609 svi) ( 530.179 wet ) Aldridge et l. 008 WEST, Inc. 6
Methods-Golden Egle Nest Survey Aeril helicopter survey were conducted from April 18 through April 6, 011, when golden egles were expected to be incubting eggs or brooding nestlings. Nest designted s: (1) unoccupied if the nest ws not selected by golden egles for use in the current nesting seson () occupied if the nest ws used for breeding in the current yer Aldridge et l. 008 WEST, Inc. 7
Methods-Cpturing Golden Egles Trgeted golden egles in four territories Cpture efforts were before egglying to minimize the influence on reproductive success. Pdded leg-hold trpping technique for ll cptures (Bloom 1987), with fresh, nturl bit items for ttrctnts Aldridge et l. 008 WEST, Inc. 8
Methods-Cpturing Golden Egles Cptured dult golden egles were fitted with GPS PTT trnsmitters weighing 86 grms. Non-trgeted individuls (e.g., non-breeders) were bnded, mesured, nd relesed t the point of cpture. Aldridge et l. 008 WEST, Inc. 9
Methods-Model Development Lndscpe Fetures elevtion elevtion_men slope slope_men rugged rugged_men rdition rim_edge Vegettion NDVI SAVI wetness brightness greenness shrub nest lek Aldridge et l. 008 WEST, Inc. 10
Methods-Model Development GPS dt Used loctions obtined from -hrs fter sunrise to -hrs before sunset, when Golden Egles were most ctive nd when GPS fix success ws highest (98%) Excluded 8% of ll loctions tht were locted outside of the study re from the nlysis Developed seprte models during three different biologiclly meningful sesons in 011: spring: (lte Februry to erly Mrch June 30); summer (July 1 Sept 15); nd fll (Sept 16 Nov 1). Aldridge et l. 008 WEST, Inc. 11
Methods-Model Development STEP 1 Egle 1 Used nd Avilble Dt Egle Used nd Avilble Dt Egle 3 Used nd Avilble Dt Egle 4 Used nd Avilble Dt RSF1 RSF RSF3 RSF4 STEP All Egle Used nd Avilble Dt Re-estimted RSF1 Re-estimted RSF Re-estimted RSF3 Re-estimted RSF4 STEP 3 STEP 4 Averge Prediction Vlidtion WEST, Inc. 1
Methods-Model Development: Step 1 STEP 1 Egle 1 Used nd Avilble Dt Egle Used nd Avilble Dt Egle 3 Used nd Avilble Dt Egle 4 Used nd Avilble Dt RSF1 RSF RSF3 RSF4 Avilble Hbitt Minimum convex polygon (MCP) round ll observed GPS loctions for ech individul within the boundry of the study re The number of vilble loctions selected from ech home rnge ws times the number of used loctions for ech Golden Egle. Resource Selection Models We incorported the covrites into binry logistic regression eqution in use vilbility frmework with mximized likelihood to estimte n exponentil RSF tht predicted the reltive probbility of Golden Egle hbitt selection. WEST, Inc. 13
Methods-Model Development: Step STEP 1 Egle 1 Used nd Avilble Dt Egle Used nd Avilble Dt Egle 3 Used nd Avilble Dt Egle 4 Used nd Avilble Dt RSF1 RSF RSF3 RSF4 STEP All Egle Used nd Avilble Dt Re-estimted RSF1 Re-estimted RSF Re-estimted RSF3 Re-estimted RSF4 Combine ll used nd vilble dt from ech individul Re-estimte individul RSF models to the combined dtset Account for the vribility in hbitt selection mong individuls WEST, Inc. 14
Methods-Model Development: Step 3 STEP 1 Egle 1 Used nd Avilble Dt Egle Used nd Avilble Dt Egle 3 Used nd Avilble Dt Egle 4 Used nd Avilble Dt RSF1 RSF RSF3 RSF4 STEP All Egle Used nd Avilble Dt Re-estimted RSF1 Re-estimted RSF1 Re-estimted RSF1 Re-estimted RSF1 STEP 3 Averge Prediction WEST, Inc. 15
Methods-Model Development: Step 4 STEP 1 Egle 1 Used nd Avilble Dt Egle Used nd Avilble Dt Egle 3 Used nd Avilble Dt Egle 4 Used nd Avilble Dt RSF1 RSF RSF3 RSF4 STEP All Egle Used nd Avilble Dt Re-estimted RSF1 Re-estimted RSF1 Re-estimted RSF1 Re-estimted RSF1 STEP 3 STEP 4 Averge Prediction Vlidtion WEST, Inc. 16
Results-Golden Egle Nest Survey 3 occupied golden egle territories (0.10 territories per km ) Occupied territories ppered evenly distributed throughout the study re with n verge inter-nest distnce of 4.71 km during 011 WEST, Inc. 17
Results - Cptures Cpture efforts occurred over 11 dys within 4 different territories between Februry 17 nd Mrch 16, 011 Two dult mles nd two dult femles were fitted with bckpck stellite telemetry pckges vi hrness system One of the cptured golden egles ws determined to be -yrs old bsed on plumge (bnded nd relesed) WEST, Inc. 18
Results Hbitt Selection Golden Egle ID Sex Seson # of Observed Loctions Size of MCP (h) Golden Egle 1 Golden Egle Golden Egle 3 Golden Egle 4 Femle Mle Femle Mle Spring 981 0,9 Summer 548 8,434 Fll 183 59,015 Spring 1,07 6,771 Summer 75 64,786 Fll 439 55,661 Spring 1,17 3,818 Summer 690 48,50 Fll 39 104,86 Spring 1,108 11,341 Summer 790 54,47 Fll 556 56,351 WEST, Inc. 19
Results Hbitt Selection WEST, Inc. 0
Results Hbitt Selection Distnce to nest, slope, rugged, nd brightness were repetedly importnt predictors of golden egle hbitt selection Distnce to nest ws in ll finl RSF models except for one egle where distnce to nest ws only included in the spring model Moderte level of ruggedness ws generlly selected Moderte to higher levels of brightness nd slope were commonly selected WEST, Inc. 1
Results Hbitt Selection Spring Summer WEST, Inc.
Results Hbitt Selection Fll WEST, Inc. 3
Results Hbitt Selection Model Vlidtion Spermn s rnk correltion coefficients estimted during vlidtion of the finl resource selection functions. Golden Egle ID Spring Summer Fll Golden Egle 1 0.99 0.8 0.787 Golden Egle 0.989 0.846 0.863 Golden Egle 3 0.879 0.96 0.896 Golden Egle 4 0.947 0.971 0.946 WEST, Inc. 4
Summry Documented 3 occupied territories Cptured 4 dult egles Developed 3 mps estimting the reltive probbility of golden egle use for nesting breeding pirs. Nest, slope, nd terrin ruggedness importnt hbitt fetures WEST, Inc. 5
Mngement Implictions Quntittively mesure risk Identify conflict res prior to development Quntified potentil impcts ssocited with hbitt chnges in before nd fter development type scenrio Non resident vs resident vs trnsient Appliction to other study res Mountin/cnyon/ sgebrush lndscpes Nesting inventory Future reserch Perch vs flying priori models WEST, Inc. 6
Acknowledgements Anonymous source provided funding nd ccess to the dt We thnk the Idho USFWS nd BLM Field Offices for sponsorship Jmes McKinley fcilitted cpture nd instrumenttion of these golden egles WEST, Inc. 7
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Results Hbitt Selection Spring Seson Golden Egle ID Golden Egle 1 Golden Egle Golden Egle 3 Golden Egle 4 Finl Resource Selection Functions + ( 3.717 elevtion _ men) ( 0.381 nest ) wx ( ) = exp ( 0.115 rdition) + ( 36.034 rugged ) ( 4354.400 rugged ) ( 83.600 brit) ( 441.895 brit ) ( 0.404 nest ) ( 109.367 rugged ) w( x) = exp ( 1759.370 rugged ) ( 0.913 shrub) + ( 0.150 slope) ( 0.00 slope ) ( 0.450 nest ) ( 0.177 lek ) + + w( x) = exp 35.454 brit 530.179 brit + ( ) ( ) ( 75.831 rugged ) ( 517.05 rugged ) ( 0.488 nest ) ( 57.08 rugged ) + w( x) = exp ( 4801.47 rugged ) + ( 16.609 svi) ( 530.179 wet ) WEST, Inc. 9
Results Hbitt Selection Summer Seson Golden Egle ID Finl Resource Selection Functions Golden Egle 1 ( 0.73 slope _ men) ( 63.077 rugged ) + wx ( ) = exp ( 415.813 wet ) ( 1155.340 wet ) Golden Egle ( 0.613 nest ) + ( 9.784 brit) + w( x) = exp ( 3.544 green) ( 0.134 rdition) + ( 0.1 slope) ( 0.004 slope ) Golden Egle 3 Golden Egle 4 ( 0.613 nest ) + ( 5.13 brit) ( ) ( ) w( x) = exp 0.134 rdition 8.83 rugged _ men + ( 0.11 slope) ( 0.615 nest ) ( 13.333 brit) + w( x) = exp ( 0.16 slope) ( 0.003 slope ) ( 19.039 wet ) WEST, Inc. 30
Results Hbitt Selection Fll Seson Golden Egle ID Finl Resource Selection Functions Golden Egle 1 ( 0.061 elevtion _ men) ( 0.113 rim _ edge) + wx ( ) = exp ( 54.503 rugged ) ( 5607.760 rugged ) Golden Egle ( 0.373 nest ) ( 87.173 rugged _ men) + w( x) = exp ( 8813.050 rugged _ men ) + ( 0.116 slope) ( 0.001 slope ) Golden Egle 3 ( 0.365 nest ) ( 0.835 shrub) + wx ( ) = exp ( 0.116 slope) Golden Egle 4 ( 0.369 nest ) ( 1.810 elevtion) + w( x) = exp ( 0.055 rdition) + ( 0.147 slope) ( 0.00 slope ) WEST, Inc. 31
Methods-Model Development: Step 4 Leve one out K-fold vlidtion process Removed one individul from the combined dtset Re-estimted the predictions using the other egles dt Tested the reltionship between these predictions nd the number of used loctions from the individul left out. Higher correltions indicte the dt nd process used to crete the finl predictive mp ws robust to mongniml vribility in hbitt use. Aldridge et l. 008 WEST, Inc. 3
Results Hbitt Selection Covrite Egle1 Egle Egle3 Egle4 Spring brit_men + +* brit_men - -* elevtion_men +* lek + nest -* -* -* -* rdition_men - rugged +* +* +* +* rugged -* -* -* -* svi_men +* shrub_men - slope +* slope - wet_men + Summer brit_men + + + green_men + nest -* -* -* rdition_men - - rugged +* rugged_men - slope +* +* +* slope -* -* slope_men +* wet_men -* - wet_men -* Fll elevtion_men - - nest -* -* -* rdition_men + rim_edge - rugged +* - rugged -* - shrub_men - slope +* +* +* WEST, Inc. slope + - 33