HomeMy WebLinkAboutAPA1706-2-· --.......--~
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-.·;le i.l::lpou~ent ürca of the Susitna River •. :Recause of a lac:k of
previous sightin~s. or observations of ·b-recding. percgrines in tl1e ..
Yentna -Chulitna -Susitna -~~tanuska rivera drainar.c basin, this
entire region see~ingly representa an hiatus in the breeding r~n~e of
the species. The :ic~1ana River~ hawever,. oay yet be ahO"..m to h.:"'!.ve
breeding pere~ri::1cs. Orn:ltholo~ically trained persc~l".s have \."Orked.
bowever. along th~t portion of the river between Mcr.inely Park and
Healy 4l"d 2.lthour,b they have acen gyrfalcons occasio1n:llly, they have
f ail.ed t:o see pcrcr.:rines. ·.··. · · :.
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The only breeding large fnlcon found was the gy-rfalcon. 'IVo nests of
thia spccies vere founù within 6 miles of the Devil C~nyon Dam axis.
This spli!cies vi.ll probably be little affccted by the~ ?resence of
da:~ s:!.nce both nest.s ~cre back from high "'at:er lir1it:s about 1/:! mile
and their food derives fro::t the surrounding al~ine rc~ions. It is
doubtful that they ~ould enter the canyon co hunt ~:cept on a fe".J
occasions. .-
The one cliff nest.ing large bird most: effec.ted by the dans will be the
raven -auhst:antial populations oecur there. This e1pecies is mentioned
beC3use its nent:s ar~ ~qed by other rapt:ors, pere&rincs, and gyrf~lcons
and thus the placc:Jcnt of a raven nest ca.y permit use of a led ge or
a1:ca thttt v:~~ for.::crly unsui table to eithe1: falson. However. since
ueither fa.lcon 1;Gs found nest:ing in .the èanyons proper thcre is little,
.ehance·that these nesta vould figuré importantly to th~ir population
r truet:ura. Ra"·cr;;;. ;cre co::r..ou in t..'la lover 70 aile~:= of the dam area.
}ifteen nests occurred in that area for.-an average distance of about·
4.6 miles i>etve(m ncsts._ -· (~;~:~··c',_:~}_:~;,_:)·
'l'he UG-Stiup, a:'e~S Of f:hree pair, Of. hAld. eag:les OC:CUl:TCJ ill the d3m-
sitCS in 1974. Add:ition.al e:tgles r:my. oécur in otllCl:' 7ears but it
appears th~t: the population is law and prob3bly not a signifieant loss ·
to the S?C.C.ics since they· nest t'lore. coc:notû.y along t:he river belo':.7 the:
canyon and alao alons: the tle:1ana _Ri~a& near t:be~ uppE~r end of the.
Denall sita ..
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Golden C:!~1.;:,s ·rr::::'!1J~nely occ-.J..,.,icd upl!!nd · c:liffs :~rot:rd t~1e '!'eri!>hcry
of cspecitily ::!m Dm!3ii site. • Since J.;t · i.s not klloûn -where tilcse
b ir.t .... ,.,·,. ,.:,.. ~-. --:-·· ·. '·-·r F.·.o-t,. ::.,... ... ;le v ... ,~., .• .,<:,----'-"~· -"'•·nr or i·~ -_..,. _,....,. .... ___ ................... ----·-·-.___. .... il!o4. .... ~-J ...._.._ • .ac \,..-. ..... .i....Lit-6oo-.&..6-
uplJlnd alpine arcas ~ state::1ents nbouè the il:fpact tht~ Denall site
'-ill· have on thea vould be cpeculativë.' ·. ··
Couclusions·and Ri!cc:..zendations:
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Oa· the ba::li$ of ti1e ~974 findi.n~s~ :tt"·'iâ: èoucluded that the icpttct of
the de1msites. alonr: t.i:e Susitna River. to perc~ne flllcon populations
will be nc:~gible. ' Tue impact of_; da=sites on othel~ raptor-populations
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