FrederickC. Dobler,Wash ngton Depaftment of Wrd fe 600 Capto Way N Oyrnpa Washngton98501 1097 WinteringPeregrine Falcon (Falco petegrinusl Habitat Utilization NearSequim, Washington Abstract AsDDTresirlLresdarr:aijilltlj..ljlin)nmi]n|. insrshnrgton'Thisstatr'.spoprr1alrhasgrolrr.rnlki|lgi||hese.onllmost 1ht.len5Pe|eFriIieivinteringdreashiLeSleIn\\a tnati()nt()l'slnll'cn|Jna!j.r!rnllplune|snllheSequimrrea-aodlnh{j|sx alidUutl|('1i'n|l.Ut;lil(lloPo]stltrhobilalsig iidds sigriil.a,rtll n,or' rhrn f\pecled. The home range-.for the malc ard icnal $fni 85.69 km'?ard 65.19 lmz respectirelr. |tlrk"rrlnprisr.rl2?]'iollhecoL]eclei]LiI (,,,nbi,rrl m!il, ,,l) 129i,, Introduction I ) daLacornpilcd by the \\ ashinplonDeperLment of Wildlife and reports from raptor crpcrts identi Prrrgrinr-' falcons /I'a1coperelfrnrzsJ have been in- licd this areaas a centel of peregrineacLiritv. and ten-sirelrsLudied sirrcc populations bcgan declin 2.|residential developmenl \ras creatingpolcnlial ing in the lale 19.10's(Ratcliile 1967. l9B0) as conflicts. A bctter under-.tandingol paLternsof trsc a rcsult of DD l residues accumulating in pler, (Nerl- rnight hclp plcscnc the peregrineshere and irr son 1969. Peakall cr al. 1976). lhe presenceof similarsitcs. org:uo pe-(ticidecontanrination, horr;crcr. is not thc 1)nlvlhrcat to pcrcgline hlcons. Lnnd develc4rmenL StudyArea is alteringthe lrabiLatswhir:h sLrppot both thc pcrc- grinc antl its plev. Betleen 1960 and 1990 Secpirn lies near lhe northeaslcr-ncorncl ol the $'ashington Slalr's human populrtion gret h,v O!-mpic Peninsulaalong tlre Strait ofJuan dc !uca i00lo.making it rrowLhe second most dcnsclv popu- (!ig. 1) on a plain betueen the foothills of thc lated ol the \reslerir staLe-r.Parts of S'cstcrn Ollmpic filountains and the sLr-ait.This icrtilc plrin S'ashinglon. l,".hcrcmuch of the recent growlh has is u mixtrue of small larms :rnd resiclenLialdcvdop- occurred. are ilnt)oftantwinLcring arcas ibr pcre- menLsand is dir.idcd bv thc f)ungenessRirer. grines. In Clallum Countv. r'hele -{equirn is lo- (lonilerousfofesLs sufround thc farmhnclson the cated. populationgrowth has outstrippr:dthc rc-tt undcrclopcd upltnds and colif;r slandsgro\\' in- of lhe stiltc$ith an 850/0inclease in the lastthree lersllefsed throughoul lhc arca. f)ungenessancl clecades.PopulaLion rJcnsitir:s in SrcstcrnS ashing- Secluimbavs forrr proLcclcdwalcr bodies but (r1 ton nov equal thoselbrurd in California.thc rnost ii'r onlv -.mallareas ol interlidal flals. Protcction clensellpopulatccl statc in thc west. Ofthe 3.760 Islancland Smith lsland lie in the strait east arrd 'lhc krn oi marine shoreiine in S'ashingLon {39o/ois pri- norlheastof Sequim respc<tilclr. area lies in rat-lr nsrr-d.arrd slril-.rll '.t.rrin, , nrirUnnr,rrt- thc rain shadol o{ the Ol,vmpic\'lountains and havc Lrndcrgoncmodification-.. B79o har.e seen receivesapproxirnalcly 40 cm of rainfall. moderule to selere changes.l rban areasarc cx- pandingonto rr'ilcllandsmore and rnoreeach r'ear. Methods Al lcast thrcc rrcstcrn Washingtonareas are Betreen 2l f)ecernbcrI983 anrl 21 March 198,1. kno$n to supp.,rl winler resiclenLpcrcgrrrcs: r.rr severalfielcl assistants:ud I capturerllhfcc pcrc- Sami-qhFlats (Andcrsonand l)ctsruvn 1979. An gfines.using standard laiconn tcchnique-.(Beebe dcrson et o1. 1980). Gravs Harbc,r (Doblel ancl and \\ ebsterl9B5). An immatLrlenale (\o.5095) Spencer I9Bi) :rnclLhe Sequirn area. All alc at rre- , aptur-,1,,n I Jrrlr.rrr IOBl. one immrrtrle least sorncrrhat ilssociuled rrith marine shorelines. Iimale {No. 5049) u'as capLLrfcdon 9 Januarv ln l98ll. the ar-eanear Scquim las chosen {or 198,1. and anolher imrnaLrrreicmalc (No. 5022) stuclicsof rdntering peregrine habitats because. on 10 !cbruarl' 198,1. \\e fittecl a sir-grarn Northr{estScienr:e. Vol. 67. \o. 4, 1993 231 O l99ii l)\ rhr \o'1h\.!l S(icntili.,\$o.irtnD. lll ,iil,G rr-,,\el z,- \ tl t '|, \"" ) Fi3u|t.Vic]ni$rnapsho*llgperegrirtsightinglrl.atiorr'TlrcI)oinlsrP|.$j]l ours e lhe area shosi). and !n n,)L$.ighL(rl b\ ritr!,-.Srlrs rre rhe locarionsof righr nnL "ir,s. transmitterlo a cenLralrelfi( e l)f each bird, using vation wasgiven at leastore record! regardlcssol methods similar to those ciescribeclbv I)unstan the duratic-,nof the observation. (19713).t,sing radio-ttlcrrrctn . nc locatcclthc birds The WashingtonDepartment oi S ildlile Re, and otrscrverltheir bchavior.rccording all perch motc -qcnsing Lrboratorv determined the habitat sitcs uscd and movementsand noting the time al classificationsutilizcrJ by thc radio-tagpleclpere cach ch.drpiein actil-it1.\l'hen a peregrine rva-ssccn grincsusing LANDSA l remotesensing lechniques. \ ilh I'rc\. \.,rll.rnl'toJ to,.olle,t the rem.rirr. 1,rer I then compared habitat utiiizationwith ar.ailabil- aftcr it had finishcd fccding and departed.ln the it,vb:r-sed upon habitat r:ompositionwithin thc home course of sr:archingfor thc raclio-taggedbirds we rangcboundarics and habitatcornposition oflarger sometinles observed othcr pcrcgrincs. and areasim:luding the Lotalhomc rangcs.Simultane recorclecllheir acliviticsas long rs thcv could be ous confidcncc intenals provided the means to compare rrlilizati{}nand alailabilitr (Nlarcumand I rletcrmincclhomc rangesand core areas for T,oftsguarden1980). -A.vailablehabitat *as dcfincd the ladio-Laggcdpcrcgrincs bv using the h:rrmonit bv a houndarv enclrsing all thc obscnecl data rnean mea-sLrre(rf activitr, mcthod (l)ixon and (ihap points plus an arbitrary borrlcr about 2..5 krn u,icle- man l9B0) and the cornputerprogram algorithm developeclb;- Samuel et ol. (|983). A core area Results is defineclas the ma\irnurn arca rrhere the ob There were 342 individual obseNationsof pere- sened utilizationd;slribution significantlv diliers grines durinplthe stud;-,with a total obscnation liorn a uniforrn utilizationdistribution (Samuel et time oi 225 hours. The rddio-taEigedimmature al. I9B5).I *eighted the calculationson thc ba- malc (bird 5095) accountedfor-60 hour-sand oner sis of timc. using a rnanimurnofone record for cach immature lemale (b;d 5022) accountcrlfor 79 "observation." half hour intcn'alt'ithin an (An ob- hours. An irrjured immaturc lcmalc (bird 5049) senat;on is an unbroken period of time. If a bird accountcd for 46 hours ol observation. Non- was Lrslftrr fivc minutesthe Dexlsighling became radioed birds acrrruntti for thc rcmaincler. A mini- the start of a net' obsen'ation period.) Eadr obscr- mum of eight dilferent peregrinesused this studv 232 f)obler I \\-_: 0123 s.a e ,n M et HOVE RANGE AREA Figur. 2. Horr. .rnse of;095. ar idirut,rr. nale peregrhe i!1(,',. :rrca: three males. orrc adult and tlo imrnaLrrrc; range of 65.79 km' (!igure iJ). Thc core areas fire fcmalcs. one adull and ibur immatules. Sir cclualcd25.i34 km'?anrl 13.50 krn2 respcctivcly. r{ere s('cn rcpeatedly. oDe imrnature lemale 1r'as The injured fcm.rlc had a smaller homc ranplethan obsen'ed only lwo timcs and one irnmaturc male the othcr two birds.onlv 5.67 km'zwitha corearea but oncc. ln 2I casesperegrincs were ol)served of I .56 km'. rvhere inclividrraliclcntitl could not be vcrifictl. !'ig urc I shows locationsof pcrcgrine observations. Itach of the homc rangescontainecl a diffcrent Pcrcgrinesubspecies arc not casilv discernibL:in habitat composition. \ine habitat classesrvere used thc ficld; hot'ever. all pr:rcgrincslhich r:ould bt: for comparisons;nater. coniferousforcst, mixed carefullv obscrr.cd l'ere juclged to b F. p. peale.i. hrrest. clccicluous forest. shrub-toodland, grass- cropland. sparsr: gruss. beach bale ground. and I'crcgrine No. 50.tr9, had been shot anrl other. (lrass and cropland lepresentcd 620loof rhe wourrdedbv unknol,;npersons uith a.22 cal. ri male's homc range. and opcn \,\,atercomprised Ilc. at leasthro weeksprior to her captule 9 JanLr- 2370. Ser.enty-twopclccnt ol the female'shome arv. 1984. Hcr leg injury rvasappurcnt r,".hen she range was opcn $rater. follotcd las fir'stobscrr,ed 2B Decernbcr1983. Alier cap- bv grass and cropland with I ture she wast kcn to the WashingtonState Veteri- 5 9/oof the total. Habitat utilization was not nall (ilinic. Erarninationrevealed a shattcredleg andlvzedlbr No. 5049 since her irrjury that hacl mended nn its own, although sorncwhat might have inlluenccclthe size and shapc ol this clxrkerl. Alicr a short obsenation pcriod it *as home rangr:. rccomrnendedthat shc be returned Lo thc tild Actual habitot use signifi<rantlvtlcparted fnrrn r'!ithouttrcatmcnt (IJr. Erik StaLrbcr.pers. conm.). : 'l'his predirtcd habitatuse {1'? 1443.8 ibr bird 5095, bird rvas radio-tagged rclcdsed. and X' = 556.,1for bird 5022. P < 0.005. dl : Bird 5095 hacl a calculated home rangc of [3).Within the availablehabitats each bird showcd 85.69 km'] (! igure 2). anrJbird 5022 had a homc difl;rent habitut choices. The malc used the Wintcring PeregrineFalcon Habitat 233 I : r: HOME RANGE AFEA _ _ _ fTfl-t Fislr'3. Home rangr,,1 5022. sn immlturc li,male peregrire falcon. grass-cropland habitat type significantlv more than tions nherc pcregrines rvcrc actuallv obscrled expcctcd (a :.05). and conifer forcstsand water f.,,ling. I'eregrin..*,.rc ob-err",lr,,i:rke or pLrr- sippificantlvlcss than erpertuJ. The [emaic uscd suc membersof22 dilTerentspecics. Prev remains $atcr significantlymorc than erpectcd (q :.05) l\'ere collectcd liom ili:i kills and 86 other hunts o!er the total homc range.and corriferwoodlands, were observedl,here pre'videntilv was tlctermined. mixed forest and shrub-r'oodland,less than ex- Someo[ thcsc other hunts endcclin hills but prev pectecl.tith coniler \yoodlandscomprising the rernains t'ere not collccted and therofore are not largest arr:a. Within the corc area she usecllvatcr representedin collectedpfey, but are intludcd as signilicantlvless than e\pected and used the catc- other hunts. In adclitionthree attcmpts to pirare gorics grass-cropland,sparse gpa-ssand bcach bare liom a gull rverc observed. ground rnorc than expected on thc basis of availa- Twenlv-scven bility. althoughof theseonly grass-croplandcon- percent of kills and 44 pcrcent tributed much to the total corc arca.