<br />'.il '.
<br />
<br />2-2
<br />
<br />that the ctata basE' used to construct ttle curves was obtaim:d in an unbiasec
<br />manner; i.e. inaividuc:l s observed or captured at a specific location were
<br />not driv~n ther~ from a marc favorabh- hebit(1t (see st;bsection 2.5).
<br />
<br />2.4 Analysis Techniques
<br />
<br />Habii.?t utilizc:1:ion curves are (j,pvelooeri throuch four Cot~ analysis
<br />techniques, either sin<]ly or in-co/1cE>rt (E(I\~EE" and corhniluer 1977). Us~ of
<br />E'i'lch techniouE' depenris on oata aveil?bility and type. ThO'> fOt'r analysis
<br />'tPcnr,iou~s arE-:
<br />
<br />1. freauency analysis,
<br />(:. range ant:. opt;~Uf" nncl..vsis,
<br />~. parameter overlAp, ?nrl
<br />4. indirect para~etcr analysis.
<br />
<br />l;sE' of f';Jch tec!"iniqlle deppnrs on Cleti', cVoilobility ann '!:VOi' (bcvec aM
<br />Cochnauer IS?7). Frpoufrcy ~n~lysis is rrrf~rren over all other curve
<br />cons~ruction t~chnl cues b<:causc tr.t' sh?oe of thf"' curvt'S c?n be directly
<br />ce:t-rT"'liM'(1 tram incividur;l measurE'S of habitat n;'rJlT1rtl?rs. J-.. probability
<br />(~,(Jit?bility incf'x) of l.U;s cSSi~JTlECo to tN- ir,Crer~(1flt er c1ustpr ~.Jitl1 tr.€
<br />rioht:s1: vi.:luL.
<br />
<br />~:ar.QE ,~ncJ Cpti1"'l)r.' e:n21ysi s is USf-:'C .k;~'n frr::auF;ncy ot occurrence cJ;~ta
<br />i1rE not ip'?il2blr., Cui. tT1t: rcn9~ dnC1 optimum r.cbitat conc'itions for tIlt:
<br />SPPCilS i)rc: ~,nown. J-. bell-shc,pp(; curvp is crcrm to t\"O cpt.imurlj 2nd two
<br />ri.,rOE: roints, ,.:::icl'"; arc c:.ssi::nrd rrob.'Jbility VEllups (suit;:bili~v indices) of
<br />1.G ~"n U.O, resPfc\ively.
<br />
<br />Pr:rur1Pt(:r (lv"rliJp ?nalysis is USH! ',Jhen only r.;;bHiit i"5scci2tions are:
<br />kno\JI'1 in li([; ct Sr)!~citic mec:sur..s 51;ci1 c.S ('sOTh, VElocity, sutst:ratf, or
<br />Ld"!!)~ri.,tun'. 1~1c r;,>n9"~ of ucn r.::rcr>t-o.trr ,:>ssoci,;1:r(' .Jitr: f.r~Ch !':'!t.itat type
<br />2n usr'c to d"t~r;",;nc: Op7;Ir,U~ l}nr, ran~'i' points, "nr~ thuS, vori1bii it-.y \'61u(>s
<br />cr suit'l.bi'lity ;n(;ices. IJ"(~irer:t parccf-'1ct(r analysis is bi.:se(l on hycr.:1ulic
<br />sirulction of rClbitat cCinCl110ns (';s (I(-nvrri fron c;,!:r-.f'r, bu~ rr'lrtcd, habitat
<br />pdrali)ctf'rs.
<br />
<br />I\n IFG evalu.1ticn ot eachh~bitnt suitability curv€' is 2 desiri'!blc
<br />ft:'~ture. The IFG hi'S C1f\'€lcped evaluution critfria fer f-aCil curve \iitl1
<br />ratir.9s uf E'xr.t'llcnt, good, fair , and re~onnnissance ~ri:c1t (Eove,:, an(!
<br />Cochnauel~ 1~7i'). Each is based on specific aUlcelines rc<]C!rdin<,J sample
<br />size, bioses, c,.:itn source, and statistical ritn('ss. Tlds eVe'lllation enables
<br />the cOrve ricvcloppr to ackncwledryr strengths an~ li~itations of each curve.
<br />
<br />Of thr many habitat paramp.ters thrlt mi~ht r1ftect a fist', p~nprally four
<br />are r:1ost often used witr thr concr'pt of 11;lbitct utilizatiNl curves. These
<br />art' (1Crtl~, v€lor::ity, Sl'hstri1tc type nnd tf'll1~erotur('. Aithouc!' thE'sf' are th(~
<br />ti?bitdt p(lram(!'t('rs l!selJ for the ('pd,;nnC'r~t1 Cclori'do f\ivpr fisr'fs, therE:' is
<br />noT. univrrsal agrecmpnt e:r.'onq enrr\n~H.tc. specirs blOlogists that these four
<br />p iJ a r1€ t ~ y's are tile m 0 S t i r.1 per tan t . C' tL f:' r Ii eb i t. a t pur 2 l!' e h r S s II C 11 c. s
<br />i rJstrean or ovcriHo;ar. cover may bp USPO \.~h("orl' thescapfH'ilr t.o bC' important to
<br />th~ tare,:t spccips. CE:nerCllly, thOSF h.:bitJt r;lri"lllt.'tcrs ('rf used th~t most
<br />rir,:,ctly Jftect fist; c:istribut;on ilnd viJry ...Jittl stretHl'flQ\'/. It is asslIllled
<br />that th(' ciistdbutio/1 c;r.r. abunrfanc:p (If ?ny spccips at"!? not primarily
<br />
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