Field Test of Ideal Distribution in Flock-Feeding Common Cranes

8/12/2019 Field Test of Ideal Distribution in Flock-Feeding Common Cranes

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Journal of Animal Ecology

@a"e" 19(5 @a"e" > Su!3e"and 19( Miinsi > @a"e" 1991=.

In a +"e2ious +a+e" Aonso 1991= e a"ead discussed !3esui!a&ii! o @uia > Ca"aco?s


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/"e/a"ious &e3a2iou" in coon c"anes. 8e"e, !3e +"esen! "esu!s a"e

discussed in "ea!ion !o !3e e6!ension o @uia > Ca"aco?s ode o ocsi%e seec!ion !o 3a&i!a! seec!ion. T3is ode aso +"edic!s an o2e"use o !3e

"ic3es! 3a&i!a!s, due !o !3e &enei!s de"i2ed "o ocin/ o" !3e indi2idua.

ina, &ecause de+e!ion o !3e "ea!i2e un"enea&e ood "esou"ces


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!3ese condi!ions, son ieds +"o/"essi2e occu+ !3e aDo"i! o !3e s!ud

a"ea.

T3is ss!e as a++"o+"ia!e o" a ied !es! o idea "ee dis!"i&u!ion o" !3e

ooin/ "easons. i"s!, !3e a2aia&ii! o "oos! and "es3 a!e" e"e no!

ii!in/ ac!o"s o !3e c"ane +o+ua!ion, /i2en


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19(9-199). T3e nu&e" o seeds on s!u&&e ieds did no! si/niican! die"

"o %e"o a!e" Janua" Eei/a 19(4=,and da!a on ood in!ae "a!e o 1' c"anes "adio!"aced o" a !o!a o o2e" 15)

3oe das


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aoun! o ce"ea in son ieds


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es+i!e !3e &enei!s o usin/ HCC as a easu"e o "esou"ce a&undance,

o"!ni/3! co""ea!ions coud &e done &o!3 i!3 ood densi! o" HCC, sincenu&e" o das and dai in!ae a"e cons!an! i!3in eac3 o"!ni/3!. Usin/ !3e

ood densi! e6+"essed as / 3a-1 and c"ane densi! e6+"essed as &i"ds 3a-1,

e con!"oed o" die"ences in !3e si%e o eac3 %one. To co+a"e &e!eeno"!ni/3!s, e e6+"essed ood and &i"d densi! as +"o+o"!ions o !3e su o

densi!ies in 1) %ones Ca"aco 19(4=.

e +e"o"ed inea" "e/"essions i!3 &o!3 !3e +"o+o"!ions o &i"d and ood

densi!ies. Because o !3e o sa+e si%e oe 197 a2ison >McCa"!3 19((= !o cacua!e !3e 2aues o eac3 so+e and cons!an!. e

a++ied !3e si/n !es! Be%%e 197 @"an/e 19(9= and !o i"s!-ea"

&i"ds a"ead inde+enden! "o !3ei" +a"en!s= o" +e"iods "an/in/ &e!een 4

and 19 das


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. C"anes o"a/ed in ocs, a! dis!ances o 1-'5 "o !3e "oos!. Indi2idua

c"anes s+en! !3e o"nin/ usua on on one o !3e 1) %ones in 3ic3 edi2ided !3e s!ud a"ea, o&!ainin/ !3e"e on a2e"a/e o2e" 7) o !3ei" dai

ood "a!ion. T3is +e"cen!a/e inc"eased i!3 !3e ;uai! o !3e o"nin/

o"a/in/ a"ea. To!a dai accuua!ed ood in!ae as !3us 3i/3 co""ea!edi!3 o"nin/ in!ae < "K )(7, n K 11, @ ))))1=, and !3e"eo"e e deined

!3e %one used in !3e o"nin/ as !3e ain o"a/in/ %one o" eac3 da. A!e"

d"inin/ a! idda o" ea" a!e"noon, &i"ds "e;uen! used a die"en!o"a/in/ a"ea, usua cose" !o !3e "oos!, du"in/ a!e a!e"noon.

A! )-) inu!es-in!e"2as, e !a+e-"eco"ded !3e &e3a2iou" o !3e a"edindi2idua o2e" 5-in in!e"2as and !3a! o 7-1) o!3e" "ando seec!ed adu!

oc e&e"s o2e" 1-in in!e"2as. Tie s+en! in die"en! ac!i2i!ies as

easu"ed !o !3e nea"es! second. e easu"ed !3e "a!e o ood in!ae, coun!in/

!3e nu&e" o c3a"ac!e"is!ic saoin/ o2een!s o !3e eedin/ &i"ds,3ic3 aos! e6ac! co""es+ond !o !3e nu&e" o seeds in/es!ed, acco"din/

!o ou" o&se"2a!ions o "ee-i2in/ and ca+!i2e c"anes. e cacua!ed !3eaccuua!ed !o!a ood in!ae o" &o!3, !3e ain o"a/in/ +e"iod du"in/

o"nin/, and !3e 3oe da. e aso es!ia!ed !3e ne! ood in!ae o" &o!3+e"iods, su&!"ac!in/ "o !o!a ood in!ae !3e es!ia!ed cos! o in/ !o eac3

o"a/in/ %one, !"anso"ed !o /"as o ood, usin/ @enncuic?s Me"s 19(9=. e e6cuded inco+e!e "adio!"acin/ das and das i!3

3ea2 "ain o" snoa. e aso cacua!ed !3e die"ence in in!ae "a!e


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si/niican! !e+o"a" dec"ease in in!ae "a!e. In a die"en! +a+e" e s!ud !3e

e+!o+a"asi!is in c"anes in o"e de!ai


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!ig. 3.C3an/e

in !3e S+ea"an

co""ea!ion

coeicien!s

&e!een ooddensi! and

c"ane densi! o

!3e s!ud a"ea

du"in/ &o!3

in!e"s. T3e

a""os s3o !3e

c"i!ica 2aues

o !3e

co""ea!ions


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!ig. 4.Seasona c3an/es in

!3e "ea!ions3i+ &e!een

c"ane dis!"i&u!ion and ood

dis!"i&u!ion in &o!3 in!e"s.

Hac3 +oin! "e+"esen!s one

%one. @a"ae!"ic

"e/"essions a"e s3on a!!3e sae scae !o ena&e

2isua co+a"isons. Non-

+a"ae!"ic so+es


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e6!"ee 2aues die"in/ "es+ec!i2e & a '4 and '. ei/3! and &o!3

easu"een!s e"e co""ea!ed


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Indi2iduas aso die"ed in !3ei" de/"ee o success in a//"essi2e encoun!e"s


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ac!o"s

"a!e die"ence i!3 "es+ec! !o !3e a2e"a/e in!ae "a!e in !3e oc


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!ig. 6. Co""ea!ion

&e!een !3e

doinance "an


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Ou" "esu!s a/"eed i!3 os! assu+!ions and +"edic!ions o !3e in!e"e"ence

+3eno!+e-ii!ed ode +"o+osed & @a"e" > Su!3e"and Aonso 199'=. Suc3 in!ae

die"ences "e+"esen! a si/niican! +"o+o"!ion o !3e dai ood in!ae


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c"anes s!udied=, su//es!in/ !3a! !3is &e3a2iou" a su&s!an!ia inc"ease !3e

i!ness o doinan!s.

Soe +"e2ious "esu!s on &e3a2iou" and dis!"i&u!ion o c"anes in ou" s!ud

a"ea +"o2ide u"!3e" su++o"! !o !3e +3eno!+e-ii!ed dis!"i&u!ion. T3e +oo"es!

%ones in ou" s!ud a"ea 3a2e a si/niican! 3i/3e" +e"cen!a/e o c"ane

aiies !3an !3e &e!!e" %ones


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i!3 !3e o&se"2ed !endenc o c"ane aiies o" inde+enden! Du2enies !o

occu+ !3e +e"i+3e" o"e o!en !3an !3e cen!"e o a"/e ocs o"a/in/ on"ic3 +a!c3es i!3in 3i/3 ;uai! %ones, o" e2en !o o"a/e isoa!ed !o a2oid

a!!acs !o !3ei" os+"in/, &u! s!i cose !o !3ese a"/e ocs in !3e sae %one.

H2en!ua, as !3ei" in!ae "a!e dec"eases, !3e a ea2e and /o !o a die"en!oe"-;uai! %one Aonso 199=.

T3e"eo"e, e2en o" soe doinan! c"anes, i !3e 3a2e de+enden! Du2enies, i!

a +a !o occu+ oe"-;uai! +a!c3es and %ones.

As o" a!c3in/ &e!een &i"d and ood densi!ies, as on/ as ;uai!

die"ences &e!een %ones a"e a"/e ando" in!e"e"ence is o, a 3i/3e"nu&e" o &i"ds a! !3e "ic3es! %ones a &e e6+ec!ed, since i! a +a an

o !3e oe" co+e!i!i2e indi2iduas !o s!a on !3e "ic3es! %ones as on/ as

!3ei" in!ae "a!e !3e"e is 3i/3e" !3an on !3e o"s! $"a199=.

T3is o2e"use o !3e "ic3es! si!es is aso +"edic!ed, and +"o&a& en3anced, in/"e/a"ious s+ecies, acco"din/ !o @uia > Ca"aco


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ca+aci! e6+ec!ed o" !3e "es! o !3e in!e". Ha" and a!e in !3e season,

"es+ec!i2e &eo"e ass a""i2as o i/"a!in/ &i"ds and +"io" !o s+"in/de+a"!u"es, !3e dis!"i&u!ion o &i"ds did no! co""ea!e i!3 ood dis!"i&u!ion.

T3e ii!in/ eec! o ca""in/ ca+aci! as +"o&a& !3e ac!o" de!e"inin/

!3e o&se"2ed inc"ease in !3e nu&e" o %ones used, and !3e conse;uen!inc"ease in !3e a!c3in/ &e!een c"anes? and ood dis!"i&u!ions as !3e season

+"o/"essed. 8oe2e", a!3ou/3 c"anes +"esen! in !3e a"ea ea" in !3e i"s!

in!e" season coud 3a2e a6ii%ed ood in!ae & o"a/in/ on !3e "ic3es!%ones, as +"edic!ed & !3e de+e!ion ode, !3e +"ee""ed !3ose adDacen! !o

!3e "oos!, +"o&a& &ecause !3e sa2ed !"a2e cos!s and s!i 3ad enou/3 ood.

T3is in!e"+"e!a!ion is su++o"!ed ac! !3a! !3e +a"!ia co""ea!ion &e!een c"ane

nu&e"s and dis!ance !o !3e "oos! in !3e o"a/in/ %ones, once ood densi!

die"ences e"e e6cuded, as on si/niican! in a!e Oc!o&e" and ea"

No2e&e" o !3e i"s! ea", &ein/ no! "ee2an! a!e" in !3a! season, no" in !3e

second one. In con!"as! !o !3e i"s! ea", in !3e second ea" !3e o ini!ia ooda2aia&ii! o"ced !3e c"anes !o use a %ones "o ea"ie" in !3e season. Bu!!3e 3i/3e" idin!e" ood a2aia&ii! ena&ed a 3i/3e" nu&e" o &i"ds !o

s+end !3e in!e" in !3e a"ea.

In s+i!e o !3ese in!e"annua die"ences, !3e +"ocess o adDus!en! o &i"d

nu&e"s !o ood a2aia&ii! as siia" in &o!3 ea"s. Man &i"ds e"e

o"ced !o ea2e !3e a"ea &e!een a!e No2e&e" and Janua", 3en !3e

+o+ua!ion s!a&iised a! a e2e cose co""es+ondin/ !o !3a! o !3e ca""in/ca+aci!

u!ua e6cusi2e $oss-Cus!a"d

1991=, e do no! ind i! Dus!iied !o dis!in/uis3 dis!"i&u!ion odes &ased onone o" !3e o!3e". Ga!3e", e a/"ee i!3 Su!3e"and > A+o"!?s


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Ackno&ledgements

e a"e /"a!eu !o C. Be"ns!ein, A. aceni, .J. Su!3e"and, and !o

anonous "ee"ees o" 3e+u coen!s on ea"ie" 2e"sions o !3e

anusc"i+!. T3is is a con!"i&u!ion !o @"oDec! @B91-))(1 o !3e i"eccin

$ene"a de In2es!i/acin Cien!0ica T#cnica.

"eferences Aonso, J.A. > Aonso, J.C. Eei/a, J.@. Bau!is!a, L.M. Aonso, J.A. Me"s, J.@.


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Hns, B. > $oss-Cus!a"d, J.. eeneside, M.8.A. Su!3e"and, .J.


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Su!3e"and, .J. oan, @.M. @a"e", $.A.

Documents

Field Test of Ideal Distribution in Flock-Feeding Common Cranes