'". ene~getics of. greater,scaup (Aythya mari1s), and /'. lesser scaup (A. affinis) during, migration. Department of Renewah1e Resources, '

Transcription

1 _._ _.-'._ { '- Aspects of the '. enegetcs of greater scaup (Aythya mars) and /'. lesser scaup (A. affns) durng mgraton f j:: < l ) }!- > r by Wa A. Chappe.l- -' '( $ f j ( ') - A thes ubmtted to the Fa cult y of GradtÎa.te Studes and Research of MCG:.l'tlvers n partal fulfhlnt: of the requrements for the' degree of' ) 4 Master of Scence Department of Renewahe Resources ' Macdonald Coege of McG Unversty Mont:'eal Quebec ) Agus t 982 6

2 . l '.. Suggested short ttle ENERGE'rICS OF MITING GREATER rlesser SCAUP '.

3 l.. ABSTRACT -t 'Gt'eater scaup (Aythxa marlà) and lesser scaup (!. a;; '0 were 0 '- studed durng the!r sprng and fall mgrat at Lke St. Lous o 0 Québec (45 24' N 73 50' W). Ttme-actvty buds were determned. and nu trent reserve levels wer motored. Metfor èsttmatng < reserve lpde n mgratng scaup were evaluated.. ' Comparsons of arly and late sprng sc'au rè.yaleans' n' frequence of behav0urs over the 'mgratory perod.'-(me-actvty.budgets dffered between sexes wthn a speces. Behavour appeared to be nfluenced by levels of srents.ex ratos and possbl changes n the food reso urc. 'Greatescaup exhbte ncrasd weghts. of fat deposts atotaljat n late sprng whereas ncreases'n proten and mean body wegh s were not sgnfcant. 'è f' Leaser scaup ha4 hgher mean-body weghts n late sprng however noreases n fat deposts 'were.'- only sgnfcant for adultma'les. Hgher proten weghts n ltê's'prng.. î l were onlysgnfcant n adult females. Dgestve organ ze could not. l' < be explaned by changes n feedn& rates and may be related to profedn... storage.and functonal changes n the gut. All females of both 8pees wer 'undergong body molt; n males molt s neglble. Durng the fall tbe durnal actvty of mgratup as. ' restrcted. to restng and preenng. 'Increases 'n body weght- over t mgra tory '- perod were observed n greater scaup. No clear pern of bodyweght.. <: / change was evdent n lesser sup. Percent bodyd skn weght were the bes t pred.ctors of ' reserve lpds n greaer and lesser scaup.. dy weght and body'weght/ body length provded relable estmates o.f lpd rl!serves. A sngle equatdh. usng abdomnal fat was de{ved to este reserve &lpds' for. both speces.

4 _ _ _ _-_..._._.... '._.a;i_b_'r'''''''''' /' ABREGE e gqmd mrllon (Aythya marha). et le pet'ft morllon (A. afuns) ' ont été étudés lors de 'l'urs mgratons' au rntemps et à l' autorîme au o Lac St-Louts Québec ( N ' 0). Lesbudgets énergétques ont été détermnés et les réserves de matères nutrtves' dans le corps. ont été évaluées..t ' On a également évalué des méthodes pour estmer les réserves de lpdes des morllons en mgraton. La f;équence de comportements état dfférete entejles ndvdus mgrant au début de la pérode de mgaton et les mgrateurs tardfs. ' ntre es < Pour une même espèce les budgets. {... r.. deux sexes. Le comportement énergétques étaent dfférents semblat être dépendant des quanttés. de réserves nutrtves du rapport de sexe. et des changements dans le régme almentare. ' Les pods des dépôts de grasse et des matères' grasses totales étaent plus élevés vers la fn du prntemps alors que les varatons du pods ds protenes et dupqds du corps n'étaent 'pas shcatves. Tard a prntemps le pods-moyen du pett morllon état plus élevé; ependant augœentaton' en dépôts de grasse n état sgnfcatf que pour les mâles adultes. Vers la fn)lu prnte.mps les quanttés de '::. poténes sont sgnfcatvement plus élevées èz les femelles adultes. Les dmenons du tube dgestf ne s'explquent pas par des modfcatons du taux d'almentaton mas plutôt par l'emmagasnage de proténes et les changements fonctonnels dans l'ntestn. La mue chez les males - état g4geable toutefos toutes les femelles des deux epèces étent Cl en pérode de mue. l'

5 t IEl... J...&2..( '... JeUlJloldUIl!... r.. () :IJ.'. A l'autodule c;hez les morllons en mgraton l'act4:vt durne se - lmte au repos et al lssage des plumes. Pendat la pérode m!grtore - l' on observe des augmentatons de pods chez le grand Ulorllon. POll le ll pett Ulorllon les cbangetnents de pods ne la:f.ent pas suvre n patron défn.. Cqez les grands et petts morllons les melleurs ndcateurs 'de. rése:ves de lpdes -sont le pourcentage d'eau dans le corps et le pods de la peau. Le pods total et le rapport du pods tota sur la longueur d d ' ' U?orps procurent une bonne estmat on e reserve de lpdes. La grasse abdomnal. a serv d base ou dérver une smple equat:on pour estmer () la résetve- de 'p?e pour les deux espèces.. j :. / C '.

6 ( ).'. TABLE OPC.ONTENTS )- LIST OF T.ABLES ' If.... LIST OP FIGURES.... Page v vu ACKNOWLEDGEMENTS! PREPACE Durnal act:l.vty and nutrent storage n -greate scaup (Aythya marla) and lesser scaup (A. affns) durng mgraton AB S TRACT INTRODUCTION.... STUDY AREA METHOnS... Censuses - Beharlour.... x ' t; ;; ( Condton and Physology ''... lifi '. Analyses Il... RESULTS..... titj î Censuses.. Sprng Behavour.. III 4 5 Fa!l Beha vour '.... Condton and Physology contou Featb è () DISCUSSION Behavour Condtôn ad Physology... '.... Contour Feather Malt /.: '.

7 () t.jo r' ' '.- ' ' l '- v '.! '.. CONCLUSIONS LtTEBATURE CITE».... '- Page Estmat:l:ng lpd reserves n greater scaup '(-.;u.;:;;;;...;:;..;==. les$er scaup (A. affns) - and ABSTRA.CT ( INTROJ)UCTION METHODS / RESULTS 75 DISCUSSION ' ea..... LITERATURE élted lt... al l f ) )? Cl 'j '; ; ; _! t :Iw J

8 ; _._-..._--.._---'-----.: '- r ' 'r' ' v. - LIST OF TABLES f ). Durnal actvty and nutrnt.rage greater scaup (AytVl maria) and lesser scadp (A. affns) durng mgraton.' Page ' Table. Ratos of males pel' female n greater and les sei' scaup durng sprng mgraton on Lake'St. Lous Québec 980 :-... le e - '. 45 ;' 2. '/--'. Pergentages of greaer sèaup performng varous actvtes durng daylght 'hours n eary and ate 'sprng and mean hours per day spent hyeach duckn hese ac.t'v'tetf...' 46 Per ntages f lesser scaup performng varous act es dùrng daylght hours n early and late sprng d mean hours per day slfent hy each duck n ; hese act tes..... : f o! Table 4. Table 6. Comparson of ody paramet:ers of early and ate sprrg' mgrant greater caup collected at Lake St. Lous Qubec Comparson of ndèes of lpd reserves.(body weght/ body length) of male and female adult greater scaup collecteddurng sprng Compa'rson of body parameters of early and late sprng mgrant' lesser scaup collected at Lake St. Lous' 0 Quebec 980. * '. t.. Table 7 Comparson of ndces of lpd reserves (body weght/ bodylen8th) of male and femae adult lesser scaup collectd durng sprng Table 8. Comparso of body weghts (g) of early and late fall greater scaup collected and klled by hhters on Lake St. Lous Quebec... ' 58 ( f Table 9. comp;son of body-hehts () of early and ate' fal..l leser caup coected and kled by hunters on Lae St. Lous Que'bec ' 4 Table 0.. '. Total molt scores of greater and lesser scaup durng early and late sprng > :>

9 . ) -. ;;. t }. () '. '. sc.aup by?ody reg0n durng Table. ' Mot. scores of sreatér early and late sprng 9'80... Table 2. Mot _ seres of lesser scaup by body regon durng early and ate sprng 980. J.. - Est.maUng lpd reserves n greater 8C!aup CAytb!a marla). and esser scaup <!. afuns): '. Page '. p o.' Table. Regresson of ether-extractable bbdy lpde (g) 0 ndependent vard.bes 'for m;.grant greater scaup J (n Il 3S) Table '2. Regresson of ether-extractable body lpds (g) on dependent varables for mgrant lesser 8caup l (n = 39)... ;: '. 83 r 0 Table 3. F values calcuated by camparson of regre:sson Hnes predctng ether-extractable lpde fqr mgrant greater and' les ser 8caup.. '-. ' 84 (. j' ) /

10 J ' t :. ;)>... l;?/.. ': ;.-.: o.' :' I.' ' '.. l' '-l..f... >;! DU actv!ty and nutt:ent j'l storage :ln greater seaup (Althya mara) and lsser seaup (A. affn.s) dt:l.ng mq8:.t::lc. '. ') - ' ;- «'.. J... Fgure. M'ap of Lake S. Lous QuebèO; s'hown8 Qbsèrvaton '! ll ponta IE'9!D whc:h bebavour 4ata werercollect:ed... ' FgUX'e 2. Combne4 ners df g.reatet and lesser scaup on.. Lake St' Lous clurng spr-ug 980 :. :... ' ; '. l ' o f Fgure '3. Combned numbers-. o g:ater and les8t 'scaup bbserved ;Ln moili8 flghts rom!.ake St' LQus f t.o Lake. Tva... KOWtalS durng fall 979 and '. 65 Fgure '.. Da.y patte 'of freuence8 of -act:v!tés of grèat' scaup n eary sprng 980 : ' 66. Fgure 5..Daly pattern of frequenc.es 'of actvtes '0; greater. scaup n late sprng 980!...: 't. ' -. e..'.. l F&ure 6. Daly patte-rn.'of frequenees o aetvltes f lesser scaup n.arly sprnt '.' :'. :. :.... :.. ' Fgure. Day pattern 'Of frequencs 0 actvt;les of scaup n late sprug. 980 '....' /.' I () '. r' ' /

11 ACKNOWLEDGEMETS Ths study would nqt have been possble except for the contrbutons of a large number of people. To lst themall would be almost mpossble sa l must confne myself' to otng those who provded the most nvaluable assstance. My pdvsor Rodger D. Ttman provded encoùagèment advce throughout the pro)ect and l am especally thankful'for'hs ana. r help n preparng the manuscrpt. l am ndebtd to Rert Baley for hs help and advce t the begnnng 6f ths Ud. amlon Greeweod. (. '. f Stevé Tnke and Greg Wel provded consderable assstance n ollectng ' brds. to'us Roy and Danel Desaulners generously donated thar free tme to help wth hunter bag checks. l am grateful to Maryvonne. -.. ' - allenav tor consçentously helpng wththe processng bf specmens. Jtatstal adv<;e was provèled by many most notably Bob Clark -. H.amlton Greenwood JeanPhaneuf and Roger Belanger. - would lke ta thank my fancé Hed Juul for the moral support she rovded - ' ( f 0 my parents who generously provded me wth an automoble for feld'work. and am grateful to thecanadan Wldlfe Servce for grantng a scentfc collecng permt and ta the duck hunters of Lake St. Lous and Lake of Two Mountans who provdedme wth most ofmy fall daa. Research fundng.. was provded by the Natural Scences and Engneerng Research Counel. trsonal -- ( and from support was obtaned from QueQec Provncal Postgraduate the Natural Scences and Engneerng Research Counel. )

12 &l J au... tt.. tfa<t l b----. I.! (J () PREFACE Ths thess eonssts of 2 manuscrpts concerned wth aspects of the energetcs of the sprng and fal! mgratons of greater scaup (Aythya maria) and Iesser scaup (!. affns). Both manuscrpts are o n the form for submssob for publo.. The frst s a draft; the second has been accepted for publcaton by the Canadap. Journal of Zoology. The frst manuserpt examnes the mportance of stopover reas for mgratng greater and lesser scaup. Two approaches have been taken to gan understandng of ths topc; behavouraî and physologea!. Tho behavoural approacb enes be allocaton of tme n orde to fulfll the physologcsl requrements of mgraton. Khwledge behavour provdes an understandng of how an organsm nteracts wth ts envronment. The physologeal approaèh examnes the use and storage.. of nutrents n the fom of lpds and protens and concurrent changes n dgestve orgns. of ;: -.l 'f f l The second mauscrpt of ths thess examnes methods of quckly and eheaply estmatng reserve lpds ln scaup. The am was to pr9vde a sngle ndex of reserve lpds whch could be used for both' speces. The ablty to evaluate lpd re'serves n these brds wll contrbute to the understandng of nutrent reserve dynamcs. ) o

13 è. (.) '--«- Q....c.! storage n greater scaup (Aythya utarla) Dul actvty and nu trent and lesser scaup (!. affns) durng mgraton. r J / '-- -'If : ' '-' '- l' 'f l. l- I.. ()../ ) ' <? o

14 _ --...''---_._--'-...- /3 ;' ( ) f > o The portance. ABSTRACT of stopover areas for greater seaup (Aythya mara) and lesser'scaup (!. affns) durng mgraton was studed durng the. / 0 0 sprng and fall at Lak St. Lous Quebee <;5 24' 73 50' F). Tme - j budgets f durnal behavours were determned f each speces separately from 23 Mareh ta May 980. Comparsons ofeatly and late sprng mgrants revealed that greater seaup exhbted an ncreased frèquency of rstng n late sprng. and deereased frequences of feedng swmmng and flyng Frequences of most behavours dffered between sexes durng bath tme perode.. Male and female lesser scaup showed ncreases n restng nd reenng ---Î n late sprn8 however slght lncreases n feedng n late sprng were.l not sgnfeant. Dther actvtes were performed less frequently n late Bprng. Smlar ta greater Beaup frequences ôf behavours dffered between male and female lesser seaup. behavour of greater seaup and lesser Beaup wa restng a prenng. Durng the fall durnal restrcted prmary to Feedngoccurred almost entrely' at nght. ''' t ';-. ' - î 'l J ' < l. J! Comparsons of body parameters of early and lte sprng brds were made on 35 greater seaup and 5 lesser seaup 'collèeted by shootng.... Greater Bcaupexhbted a slghtly hgher mean body we±gnt n late sprng. Mean weghts of the skn ntestnal fat abdomnal fat and total fat ere larger n late sprng. Slght ncreases n proten weghts and fat-free weghts were not sgnfeant. Dgestve organs of adut greater scaup.dd ndt change wth the xcepton of large ntestne length wheh d decreased n late sprng. Sample szs of juvenles were small but data suggested an nerease n ntestnal sze. Mean body weghts ôf () [

15 r ;---. L. - 0 () '---'--j lesser scaup were hgher tn late sprng :... t:z::... Increases n fat dépost weghts... _wr.....!.._p 4 were observed but these were only sgnfcant for adult males. l ' Hgher proten wegbts n late sprng wre only sgnfcant for adult females.' Jlereas hgher mean values for fat-free weght were not sgnflcant ln any age-sex class. Changes n dgestve organ sze n leser ' SC8Up appeared to be-ltmted to creases' n ntestnal wght. Adult and' juvnle males of both speces exhbted ltt le body molt wheras ail females of both speces were undergong bo'dy molt. Durng t:he fau mgratons n 979 and 980 body weghts were obtajned from hunter klled brds.- Weghts. of 92 greater scaup and 92 lesser scaup were measured durng both years combnéd. AlI age-sex classe 7 s of greatér o scaup had hgher mean body weghts n late fall -howeve fferences were not always sgnfcant. No clear pattern of body weght change was evdent'n lesser scaup. Concluson'were J that stopover afeas such as Lake St. Lous were ) used by mgratng scaup to replensh nutrent reserves to be nfluenced by levels of stored lpds n brds the rato of Behavour appeared males to females and pble changes n the ood resource. Changes n. VI dgestve organs could not be explaned by changes n feedng rates and may be related to proten storage and -functonal changes n the gut. -.. '

16 5 INTRODUCTION Body weghts of mgratng dtcks havebeen reported by ny authors _ kncludng Bellrose and Hawkns 947 Nelson and Martn 953 Wller '0 Mendall 958 and Belrose 976). Ducks gan weght durng the sprng -and fa as fat s beng stored for mgraton OIeer 957 Folk Owen 970 Erskne 97 Ran 972 Peterson nd Ellars9!9). Durng l ' the perod of premgratory hyperphaga gant Canada gees (Branta canadenss maxa) exhbed large weght gans due to pd and proten storage (McLandress and Ravelng 98). WeIler (957) showed that redhead dûcks (Aythya auercana) lose lwf!gh t durtng the course of mgr a tan. 'Harrs (n - Fredrckson and Drabney 979) be;leves that _waterfow use 'stopove'r.. areas to repensh reserves. Leser. snow geese (Anser caerulescens caerulescens) ccumulate nutrents whle stagng t James Bay (Wypkema -:; and Ankney 97?). Segfred (974) concuded that the Delta marsh n.' Mantoba s an mportant feedng and restng area for lesser scaup (Aythya affns) durng mgrâton however he made po attempt to determne f the brds were storng nutrtertts. Lpd reserves'acqured before 4. h arrvai on the breedng grounds have be shawn to be mportant for re producton (Harr s 970 Krapu Caveryand Boag'977). Durng the course seems reasonabe tnat ducks shoud repensh the body ds ed as fuel du rng mgratory fght. Snce.. lpd and proten meta olsm are nterrelated (Hanson 962) 'brds usng. stopover areas dur!ng mgraton should show an ncrease n bo4y protens l concurrent wth ncreasng lpds. Segfred (974) stated tnatknowedge of.a speces behavour at a p gven place contrbutes.a to the 'unaerstandng of the speces requrements f /-

17 { (}. and tne mporance bf that-place. Reently everal etudes have examned tme-actvty relatons n breedng postbreedng and wnterng. ducks (Klma 966 Folk 97'Segfred 974 Tamser Dwyer 975; Mller 976 Segfred.!!.!!. 976a b Skead 977 SeYmour and Ttman 978 Afton 979 Stewart and Ttman 980 Ttman 98 Baley 982). Tme-actvty sudes of Aythya durng mgraon are lmted to Segfr's ) (974) ork on esser scaup as they approached the breed:f.ng grounds. Tme-actvty bdgets. rovde greater understandng of the 'use of'stopover areas along mgratory routes. montored farther from the breedâng grounds' should ' 6 Greater scaup (A. mara) and esse; scaup mgrat long dstances beeen wnterng and breedng grounds. Greater scaup brled n the western arete n North Amerca and wntr a0ng the Atlantc and Pacfe coasts the Great Lakes and along the Gulf of Mexco. Lesser scaup breed n nteror northwestern Nort Amerca from central Alaska and weste Canada north' to the tree lùdt and east as far as the Laurentan Shed south to Mnnesota and northeastern Calforna. Wnterng areas nclude the Atantc and Pacfe eoasts the Gulf of Mexco and extend nto Mexco and Cent aamerca. More dètaled descptons 7 and esser scaup are gven by Belrose (976). of the ranges of greater Durng the mgratory _ perods n sprng and fall both speces use' the St. Lawrence Rver system n 60uthwestern Quebec as a stopover area. The am of ths study wa to gan an understandng of the mportan of stopover areas for mgratng seaup. lt was hypotheszed that brds usng these are as repensb ItPds and pro tens spent to power mgra tory fgbt. Over the course of mgraton hgh eves of food n tae should resut n' ncreased lpd deposs and. proten reserves and heaver body wéghts. proten s stored n dgestve

18 ---..:.-.-.:...:...- -_._'... U... C). organs (Ankney 977 lcorschgen 97 Balley 92) (Kendall.!!.!!. 973). nd n flght muscles Dgestve organ sze a also related to the level.. of food consumpton (Fenna and Boag 974 Mller nte 976a b Ankney 977) therefore nterpretaton of organs rqures nformaton ê)n feedng rate8. Tme spent feedng brds utzng stopover areas should aso reflect the quaty an of the food resource. J Î J! < f o. -

19 ------t'--. l l' ft 'J--_ M<... _Al '. ti 5<fl! œ'j;j;.!!e.:mi)t4... hfm.... I. ' STUDY!REA o The study was conducted prmarly on Lake St. Lous Quebec (45 24' o N 3 50' W) whch les at the southwestern end of the 8and of Montreal. (Fgure ). It 8 an enlargement of the St. Lawrence Rver where t s joned Dy waters from the Ottawa Rver and 8 tnerefore not a true ake. Approxmatey 8 km n ength and 0 km at the wdést pont t s generally shaow. The suhatrate a prncpaly slt and élay and extensve beds of vegetaton le long the south shore and n-the mddle of the lake. Plant speces are numerous and varable but domnant speces nclude Potamogeton rchardson Vallsnera amercana. Anachars canadenss. AlSUla sramneum; MYrophyllum spca tum and Chara spp. ; Bageau and Lévesque (964) and Gravel and Lévesque (977) provde a!! detaed descrpton of the aquatc végetaton. There s a rge human populaton (> ) surroundngthe area thus recreatonal use of the water 9 'extremely hgh. The eastern ha If of Lake of Iwo Mountans ( ' N ' W) was ncluded durng fall hunter bag surveys. Ths s a long wde basn at the 0wer end of the Ottawa Rver mmedately upgtream from Lake St. Lous. lt s ahal0w and turbd and lacks the extensve weed beda and heavy recreatona use of Lake St. Lous. r.

20 e ( ) Censuses V! METHODS 9 Aeral cesusng was eonducted every 7-8 days from 2] March to 0 May' 980 to assess numbers of scaup and to locate areas of use. AlI j observatons were made from a fxed-wng areraft and the locaton and sze of eadh flock was reeorded'-purng the fall aeral surveys dd not prove successful as brds were eontnually movng and often dffcult ta locate due ta heavy huntng pressure. An ndex of total all numbèrs was obtaned by estmatngthe numbers of brds observed flng from Lake St. Lous where they fed at nght to.lake of Two Mountanswhere they rafted durng the day. Counts were made at the northwestern shore of Lake St. Lous and wee attempted weekly ( } however successful counts were dependent on weather. Thornburg (9P) found that the magntude of daly flghts on Keokuk Pool Iowa wâs drectly propotonal to the populaton of dvng ducks. Sùrveys made by arplane and by poat revealed that large numbers of brds seldom remaned on Lake St. Lous. durng the durnal perod atter the mornng r ù flghts were completed. lt was usually mpossble to dstngush between greater anq lesser scaup bath from the ar and durng.mornng f!ght counts so values presented nclude both speces. Behavour Actvty of unmarked greater and lesser seaup was sampled by con7 r tnuous scannng (Altmann 974). Observatons were made wth a spottng telescope and the actvty of each duck was recorded on cassette. tape. ' > Behavoural actvtes were dvded nto the followng categore$: () feedng; (2) restng ncludng.sleepng; (3) preenng ncludng

21 0 bathng and comfot movements; {4) swlln8 Incudlng courtshp and alert behavour; and (5) flyng. Seans vere made e'very 0> 5 20 or 30 mnutes dependlng o th'e number of brds pre'sent. Scaup were observed so that ail daylght hours were sampled every 2-4 ays. Data vere c pooledfrqm 4 separate locatons durng the sprng ta reducbas assocated vth area related e. Durlgthe'fall brds vere dfcult. j to obsee de 2 locatons only. to thar dstance from shore and data vere pooled from Condton and Physology.' Greater and lesser scaup vere eollected wth a shotgun durng'thelr fall mgratons n 979 and 980 and durlng thetr sprng mgraton ln 980. Brds vere aged by the bursa of Fabrcus and by Plumag'Chaacterstcs (Palmer 976). Brds were dred wth paper towe weghed fresh to 0.5 g and frozen wthn -2 hours n sealed polyethylene bags for Iater analyses. 'Ihawed brds were reweghd bt weght lobs rarely exceeded g. Brds were sknned and dssected and the followng wet weghts to 0.0 g were taken: () unplucked skn ncludn the subcutaneous fat but exclud- ' ng wngs and feet; (2) breast muscles (pectorals supracoracodeusand coracobranchalrom one sde; (3) muscles of the femur and tbotarsus '--. '-. tcng these bones fr_one leg; (4) gzzard; (5) smal ntestne dlned at the juncton wh the gzzard and at the ïlocaecalcolc aj; (6) large ntestne severed t the vsble juncton wth the cloaca; (7) combnedcecae; (8) abdomnal fat depost; and (9) ntestpal mesenterc fat. Pror to weghng ail vsble fat was removed from muscles and organs. Dgestve organs were eut along ther length rnsed under runnng water l ' - ;

22 '-r ' :; ' J l ( ') ta oremove. ngeata patted dry wth paper towel and weghed. ( Measurements ta.0 mmwere taken of () small ntestne length; '- - (2) arge ntestne length; and (3) combned cecaalength. Care W8S taken not to stretch these orans durng rnsng aud surng. Skns.were scored for contour feather molt usng a general:tzed peryloss dagram descrlbed n Bllard and Humphrey' (972). Ths was dvded nto 5 body regons: () head and neck; (2) sdes and flanks; (3) upper breast and upper back; (4) lower breast and belly;and (5) md- J back and rump. It was not possble ta dstngush between contour featber... malt 'and down feather molt the head and neck regon therefore ths o! regon was not ncluded n the scorng. As n Bllar4 and Humphrey (972) () each reg0n was subdvded fto amaller unts of smlar sze to facl-. The skns were.ferapeêl free of fat and numercal scores ndcatng molt ntensty were enfered ne.ch subdvson. Scores were as follows: no molt 0; lght malt ; moderate molt 2; and heavy molt 3. malt score for each regon was caculated byaddng the scores 8ubd!.rons wthn the reg0n :nd th dvng b) he be dvsons. 'Mean molt scores for the 4 regons were then dded The mean of the of stogether to gve the total mean molt score of each brd. The maxmum total mean molt l. score for Any skn was 2. Mqlt scorng was done on sprng scaup only s fall sample szes of who le brds were too small. The skn was then'plucked Abd the entre brd excludng the plumage feet bll was ground n a meat grnder and thoroughy homogenzed n a! ' (' bleoder. Two 20 g samp.es oj; each. homogenate were freezedred at -50 C... and 5 mcrons of pressure to a constaneght to estmate ter. content. ' r

23 ';! ad ( ) Dred samples vere fnely ground and shed n anhydrous ether for 8 hours n a modfed Soxhlet apparatus capable of holdng 20 samples. 2 tl I h.. Samples we;e dred n a vacuum aven overnght then reweghed to estmate l'pd contant. The non-ether extrac.table resdue of the semples vas. used as a proten ndex (Ravelng 979) Durng the fall brds were dffcult to collect due to heavy hunt. pressure so addtonal data on body weght wëre obtaned from hunter- klled seaup Brds were weghed to 5.0 g on a Pesola sprng scale.' Analyses -/' Physologcal Jlnd behavour data were categorzed nto the followng perods for the purpose of statstcal analyses: early sprng! l from 23 March to 3 Aprlfor greater seaup and from 23 March ta {'-' 22 Apdl for lsser Beaup; late sprng - fram 4 Aprl to May for' greater seaup and from 23 Aprl ta May for lesser seaup; early fall - obfrom 20 September to 24 October for both speces; late fall - from t. 25 October ta 2 December for both speces. Dfferent dates separatng early from late sprng were used for the two eces because greater seaup arrved consderably earler than lesser scaup. Durng the fal lesser seaup may have arrved earler than greater scaup (Berose 976) but ths could not be verfed as the frst small flocks of early arrvais were dffcult ta locate or dentfy due to the large area of L water nd heavy boatng pressure.' Both greater and lesser scaup were seen durng'hunter bag checks fram the thrd week of September unt!l the P; 'begnnng of December therefore the same date was used to sepatate early from late fall for both speces. Behavoural data were compled and sorted on.an Amdahl VI computer

24 l'. o. ' '. C). 3 ï > l 'usng the Seatsttcal YrB System (Barr et àl. 979}. Cb:..aquare :. ' ' - '' ' tests were performed on raw totale to test for dfferences tu proportods - t> '. c ' _... 'J!....' (Segel 950/ To coiilpe'b8ate for ncrea&ns daylength theavel' number..! of hoq.rs 'of daylsht ('hour &efor sse to hour after suuet). vere....' tr-o. ' calculatjd. for early and late sprng perods. The percentagès 'of brds.. performna the'varous actvttes durng daylght hours vere multed 'Il {; by the avjrag number of hours of dayght to estmate the meau number ' ). of hours pr day spént by each duc:k n eath s.ctvty. Comparlsons of body parametèrs of earlyalu la te mgrants wer. _de..' ; for sprng and fa! separatèly aud between years tn the fall vth Il two- taled Wlcoxon ranksum test usng the Stattscal Analysts System J (Barr et al. 979). ).. o -. /.. Il o.. ().'

25 4 RESULTS o Censuses Peak numbers of eombned greater and esser seaup were observed on... 3 Aprl and 26 Aprl 980 (Fgure 2). The frst peak conssted prmary of greater seaup; the'frsl esser scaup were seen on 25 March durng behavoura observatons but t was not unt 6 Aprl that they were seen regularly. Greater scaup were çrst recorded durng the thrd wee of... March when the ee was begnnng to break up on the lake. Both speces l' were seen regulary nt May.althougp lesser scaup seemed relatvely more abundant than grèater scaup towards the end of Aprl. Durng the sprng Lake of!wo Mountans was of ltle mportance to dvng ducks and scaup'were rarely seen there durng aeral cepsuses. Sex ratos were determned fram observatons made-fram shore trable ). The earlest greater caup to arrve could not be observed as they were lmted to ce'-free water far fm hore. By thrtme they' could be observed greatr scaup haa been on the lake approxmately week and large numbers had arrvd. Sex ratos of greater scaup favoured 'males throuhout e sprng however ths predomnance sbpwed a graduai (. )!. decrease from late March to md-aprl. After bepg lowe ntally a smlar.patteru of decrease occurred ng lesser scaup.. The largest fa Il concentratons occurred around m - years although the 979 peak was lower and slghty earler than f.980 J (Fgure 3). Scaup were seen untl md-deeember n '979 weil a ter ee had formed n bays and along the shores. In 980 no brds were observed after the Urst week n December.

26 ù o 5 Sprug Behavour Durng 6 hours of observaton fram 23 MareIl. to May nstantaneous tme-actvty samples of greater scaup and 53. of esser scaup were recorded. Frequeuces of feedng decreased and frequences of restng ncreased for botmale and female greater scaup l!' la'te sprng (Table 2; l<o.ol). Preenng was observed IIlOre frequentiy.! n late sprng but the ncrease was oy sgnfcant for femaes (P.<O.05). Sw!mmng and flyng occurred wth decreased fequency n late f sprng (P<O.Ol). More female greater scaup were observed feedng than males n early sprng (R.<O.05) however no dfference wu found u late spr;ng. Fre- () quences of restng and preenng were greater for females than males. throughout the sprng <O.05) whereas the frequency of madng was Iess for females (P<OOl). Females were also observed fly.tng Iess frequently than males but ths was ouly sgnfcant ll eatly sprng (P<O.OI) Behavoural trends exhbted by -lesser scaup (Table 3) dudng the o sprng mgraton were smlar to those of greater Bcaup. However both males and females showed ncreases n restng and preenng n late sprng (P<O.OI); slght ncreases n feedng n late sprng by both sexes were not sgnfcant. Other actvtes were performed less frequently by - both sexes n late sprng (<O.Ql). Female esser scaup were obsel:l'û'ed feedng and preenng more frequently than males throughout the sprng (P<O.OS). Although females were obéerved restng more thanles n early. sprng (P<O.Ol) no dfference between sexes occurred n late sprng Frequences of smmng and flyng were greater for males than for feles

27 6 n both urly and Iate sprng (P<O.Ol). Fgures 4 through' 7 show the daly pattern of aetvty n 2 hour per0ds for 'greater and lesser scaup. Feedng oc:urred throughout thé. J day suggestng that ndvdual brds were feedng frequently. Ne strong daiy actvty pattern was apparent athough swmmng and flyng were 'most freqùently observed early n the day. Fall Behavour '.. Ac tv t Y patterns of both greater and esser scaup were entrely A llfferent du rng the fall. TIle brds rafted out n open water durng the day restrctng ther actvtes prmarly to restng and preenng. 'TWenty-one hours of behavoural observatons ncludng a hours of day- gh t were condue ted from'8 November te 9 November Based on 4526 nstantaneous observatons 75.6% of the brds were oberyed restng l! f! and 2.0% preenng. Only 4 nd vdu wre seen feedng. Due to the.' dstance of the brds frm shore scaup coud not be dentfed as to speees sex or agé. The pereentaes gven are based o ail scaup wth. greater seaup ftjrmng the largest proporton. The largest daytme con- èentratons of scaup oc(!urred on Lake of Two Mountàns. Occasonally raftsof seaup were seen on Lake St. Lous however hunter harassment and j even the sound of a dstant.. outbojrd motor would often cuse t.o fly to Lake of!wo Mountans.. these brds Approxmately one hour before sunset scaup would start to become restléss swmmng alertly then fyng off ' to the feedng areas n Lake St. Lous. Ths behavour lasted untl. darkness wth most b:lrds flyng between sunset and drkness. In the ( mornng flocks of scaup would lft off the feedng aress and fly back to the restng areas. The mornng flghts would usually begn at frst

28 _ltoi.. c '- c (J lght and contnue unt;t approxmatey -2 hours after sunrse tg and duraton of _e.mornng flgh'ts often pfpred : e nfluenced Thel t 7' by the huntllg pressure on Lake St. Lous. The sght and sound of motorboa ts and oecasonal chasng oy hunters would resul t --êarler fgh ts and reduced duraton of the mornng flght pérode. Durng late fau when huntng pressure was very lght scaup often remaned au day on Lake St. Lous. Condton and Physology Comparsons of 'body parameters of early ana late sprng greater seaup are preented n Table 4. Jss efforts were concentrated on collectng d ( (J adult males sample szes for other age-sex classes are small. Statst.!!8 codlpaf.sons were therefore lm ted to adul t males. Mean body weght of ( adul t males was hgher n late sprng than early sprng but ths dfference was not sgn:.fcant (P=O.lO). Adult females and juvenles of both sexes showed smlar trends. Breast muscle weghts and leg weghts showed no change over the sprng. Mean values çf gzzard weht smal ntestne length small ntestne weght large ntestne weght and combned caecae weght dd not dffer sgnfcantly between erly and late sprng for! l' - adult males whereas largh ntestne lengths were shoter n late sprng (<O.9). Adult female gre;ter scaup showed slar organ measurents. Sample ses of Juvenles are small but the data suggest a possble ncrease n sze of the ntestnes partcularly smal! ntestne length. Large ntestne length dd not appear to decrease over sprng. Mean weghts of the skn ntestnal fat abdomnal fat and total fat were larger n late sprng fol' all greatel' scaup. These- d.fferencèswn:-e- sgnfcant for adult males Œ50.05). Slght ncreases n proten weghts

29 / 8. and fat-free wegbts were not sgnfcant. Body length :l:s hghly correlated wth fatfree weght n adult greater scaup asser t. scaup (Chappell 982). Body weght 'I was adjusted B by body length to provde an ndex' of lp:td reserves to compare males and females w:tthn a spec:l.es. -Early sprlls male_and female adult greatpr scaup could not De compared due to an nsuffeent sample sze of females.. however a comparson of ndcelf of Iate sprng males and fema].es revealed no stat'stcal d:l:fference (Table 5). Body weghts of mgrant lesser seaup were sgnfcatly h'gber.. (P<O.05) n ate sprng than early sprng for adult males and females and - d juvenle 'males 'Table 6). No juvenle females were ootaned n early - spdng however the hfgh body weght of the sngle late sprng brd agreed e wth the above fndngs. Breast muscle weghts 'were heaver n late l!! sprng but ths ncrease was only sgnfcant for adult and juvenle males (P<O.05). Leg weghs dd not change over the sprng. Early and late spr adult males dd not dffer sgnfcantly n gzzard eght sma ana large ntestgths or comb:.ned caecae e.ght and length. Increases were ooserved n the weghts of the small and large ntestnes n late sprng (!<O.0). Adult females exhbted smlar trends; amall ntestne weght wl)s greater n lat sprng (!<O.OS) and a largér mean. weght was obtaned for the large ntestne n Iate sprng but ths was not statstcally spfcant. Other dgestve organs dd not dffe!' between eat'ly and Iate sp!'ng for adult females although large ntestne length appeared to be slghtly greuater n ater sprng. No statstcal dfferenees were foujd between dgestve organ weghts of juvenles n early and late sprng although non-sgnfcant changes n thé gut wre smlar to tqose of adults. The weghts of the skn abdomnal and

30 9 ntestnal fat deposts and total fat were grater sprng adul t males (P < 0.05) Increases n these! parameters ere 0 - femaes and Juvenle males but they were not sgnf Weghts of fat deposts and total fat of late sprng Juvenle. smlar to those of juvenlle males collected n t wel.'la same tme perode Fat-free weghts and proten weghts of adult males had hgher mean values n la te sprns. but dfferences were not sgnfcant. Adult females showed a' slght ncrease n fat-free weght (P = 0.08) and a sgnfcant î..! ncrease n proten weght (P < 0.05). No dfference n fat-free weghts of Juvenle males was observed however proten wegnt ncreased slghtly <.<0.07)... Comparsons of lpd reserves of adult males and femaes were made b adjustng body weght by body length (Table 7). No sgnfct dfferences wre found between sexes n ether early or late sprng. Body weghts of greater and lesser scaup obtaned durng fall mgraton n 979 and 980 are presented n Tables 8 and 9. AlI age-sex c'lasses of greater scaup 'had hgher' mean body weghts n late fah than n early fall but dfferences were only sgnfcant for adult males and j uvenle females n 979 (! < 0.0) A certan amount of varaton between yea.rs was ndcated by dfferences n mean body weghts of early fall 4. adult males n 979 and 980 and smlarly n early fah Juvenle fe-' males (!<0.05). Body weghts of adult male lesser scaup were not sgnfantly dfferent between early and late fall brds. Sample szes of females were too small to compare statstcally but data from both years ( ndcate weght ncreases durng 'tr.. stay on Lake St. Lous. Body

31 r J' ( ( weght'ncreases were sgnfcant for 980 Juvenles of bath sexes (P < 0.05) however n 979 mean body weghts of early and ate f.au Juvenles dd not dffer. Contour Feather Malt Durng sprng 980 adllt and Juvenle males of bath speces exhbted. lttle molt wth most ndvduals not moltng at ail (Table 0). Of 7 adult male greater 3caup scored n early sprng only one showed lght ) molto Late sprng adult males nd Juvenle males throughout the sprng showed no evdence of contour feather molt. All adult and Juvenle 'f$l female greater scaup were undergong body molt n early and late sprng. Generally _malt was observed n a body regons (Table Il). Molt score patterns of lesser scaup were smlar ta those of greater scaup (Table 0). Of 3 early sprng adult males scored only was moltng lghtly' and only 2 of 8 late sprng adult males showed -: J - j. sgns of malt. Smlarly of Juvenle males score throughout the sprng only l was moltng. AIl adult and Juvenle females were moltng durn both sprng perods. Most females exhbted contour feather malt!h a body regons (Table 2)... rl ( '3

32 t >- J!.(J DISCUSSION ' ;. Behavour Geateaup arrvng on Lake St. us n early sprng spend over 25% of daylgh feedng durng auses.. fee-a sgnfcant y decrease n tme spent porton of sprng passage may be due to severa The frst greater scaup arrve when the lake fs stll partally ce covered; therefore certan areas are not accessble and brds may have to spend more tme foragng n poorer qualty habtats. Tme spent feedng wll be greater f brds are forced to eed n deeper water ' () (Nlsson 970a b) or f food tems are less abundant (Owen 972). Food - j. ntake and therefore tme spent feedng wll ncrease f food qualty decreases (Hll and Dansky 954 McDonald et al. '973 Mller 975).. / Greater seaup often began to utlze areas of'lake St. Lous as the ee broke up parteulary shetered bays and shorelnes. Although many areas were used by erly and lata sprng brds some areas were used n late sprng that eould not be used n early sprng. Iee remaned n shèltered bays used by the brds untl the end of the trat week of Aprl. lt s possble that the food esouree mproved qualtatvely and quanttatvey aa addtona areaa became ee-free. The dsappearance of the ee and the nerease ln dayength over the perod of mgra ton may have allowed for nereased vegetatve growth. An evauaton of food habts wheh woud answer the questqns posed above was not possble snee very few bfds had food. n the esophagus when ahot. Folk (97) suggested that the tufted duck (Aythya fulgua) must devote most of ts tme to foragng n'eary sprng as a reaut of short ayleng d te:alable food. / '-- Al though the average dayength was

33 III'IIfI'I ft..:-r...-n--._ (. hours longer n Iate sprng the average amount of tme spent feedng 22 durnaly by greater scaup was stll less than n early sprng (Table 2). If brds were feedng at nght as well as durng tbe day then ncreasng daylength may bave had ltte effect on durnal feedng rates; Scaup shot n the eary momng generally had no food n ther s tomachs but l do not know f ey were nocturnaly actve. Attempts to observe bt;d' on moonlt nghts were unsuccessful due to the dstance of brds from shore. Klma (966) found tbat durnal and nocturnal actvty dd not dffer for - ]v-- (.the European pochard (Aythya ferna). Canvasbacts (!. valsnera) were <'J - observed to be actve on moonlt nghts durng the sprng on Delta marsh (Hochbaum 944) Contrary to ths Folk (9) found the tufted duck > (!. fulgula) showed marked durnal feedng versus nocturnal restng. Nsson (970b) has shown that scaup presumaby the old word sudspeces A. m. madia are prmarly nocturnal durng the fail and wnter showng T -. 'J e ncreased durnal fe.&dng bebflv:our durng the sprng montbs. ' Smar behavoura trends were observed for tufted ducks and pochards n the; same study. A change n ambent temperature may affect the calore requrements of brds (Smth and Prnce 93) and therefore feédng ntensty (Nllsson 970b Hckey 980). The mean day temperatures durng eary and late -0 0 ' s-prng n the present study were 5. and 7. respectvely. Applyng' the mean body weghts of male greater. scaup (Table 4) to the equaton proved by Kehdegh.!.!!l. (977) TIc W -O:809±.382 the o lower control temperature ls calcuated as approxmately 3. As mean temperatures and especally nghtly 0w temperatures were below the zone of thermj-neu tràll ty the warmer tempera tures n la te sprng May have nfluenced the decreased feedng rates observed.

34 _...._ ' _ ( ) Pesumaby 23 the man factor contrbutng to decreased feedng d.. :. ) ate sprng s that pd stores had approached capacty n a large number of brds. Once lpd reserves have been repenshed food.' consumpton and tme spent feedng should decrease. Lepkovsky (973) has shown that.food ntake s regulated by the sze Female gréater scaup were observd males n eary sprng but not n late sprng. femaes tend to arrve somwhatlater of fat deposts. feedng more frequently than Sex ratos show that many n the sprng compared to males. If arrvng brds spend more tme feedng that those whch have had sorne tme to replensh lpd reserves then hgher feedng rates for femaes shoud be observed.. In eontrabt wth greater seaup J esser scaup showed no sgnfcant changes n feedng rates over the sprng. Lesser scaup tend to fy short dstances between stopover areas durng sprng mgraton (Bellrose 976) therefore. brds arrvng at Lake St. Lous should stll have szable pd reserves. Lttle s known of the mgratory habts of greater seaup however ther prefereqee for arger waters (Bent 923 Kortrght «942) may requre longer flghts between stopovers and the use of more f l 'J J l' stored energy than esser scaup. Athough both greater and lesser seau! showed ncreases n body lpds greater seaup eoud not be coected for the frst two weeks after arrva and therefore had ample tme to. replensh reserves. (Early arrvas probaby weghed consderaby ess than ndcated n Table 4 necesstatng a hgh feedng rate to replensh l' '.. reserves used durng mgratory fght. ({ Femal:e lesser seaup were observed feedng more than males throughout J the sprng passage; these resuts agree wth the work of Segfred (974).

35 r--; _ o ( Observatons of pre-terrtoral and pre-netng sprng dabblng ducks have shawn that fmales feed more than males (Seymour and Ttman 978 AftOn 979 Dwyer et al. 979 Stewart and Ttman 980) J Cadwalls (Anas strepera) arrvng on the breedng groundshowed no sex-related dfferences! feedng rates unt!l the'pre-nestng stage (Dwyer 975). 'WeIler (957) found that female redheads showed rapd ncreases n weght upon arrvai to the breedng rounds due to ntensve feedng. The mportance of lpd reserves acqured prorto arrvai on the breedng grounds for dabblng ducks has been dscussed by Harrs (970) Krapu (974 I- _! 98) and Calverlyand Boag (977). The fact that female greater scaup dd not show a slgnfcantly hgher feedlng rate than males n late sprng as seen n esser scaup May be related to proxmty to the breedng grounds. Lesser scaup mgratng through s area are closer :{ to ther breedng grounds tban are the majorty of greater scaup (Bellrose. 976) and the need for pd reserves for nestng may be of ncreasng mportance for the former. Female lesser scaup mgratng through Delta marsh Mantoba n the southern porton of the breedng range spena 35% of ther tme feedng (Segfred 974). Ths s twce the Ume spent feedng by females at Lake St. Lous suggestng ncreased feedng as nestng approaches. Males at Delta spent approxmately the same amount of tme feedng as mates at Lake St. Lous. Mot 8 an energy demandng functon (Klng 974) and may n part nfluence the hgher feedng rates observed for femaes than males of both speces. Also snce feathers hae (l ahlgher concentraton of sulphur-contanng amno acds than do plant or anmal foods an ncrease n

36 -'-... ;.; ;l'_tlm:u_''!ii f 25.0> food Intake ls requed (Kendelgh.!S.!!. 977)... Less efflcent Insulatlve propertes of the plumage durng the molt should result n females re- < qulrng more energy.for thermorlaton. /. Ths would be most pronouneed n early sprng when ar and water temperatures were colder. Also as new feathers develop.the nsulatve propertes of the'plumage wll mprove eompared to early stages of molto Although female greater seaup exbted hgher malt scres than males n late sprng no sgnfcant dfference n feedng rates was observed between sexes durng that tme. Energy requred for mot may have been made avalable by reductons n other energy demandng actvtes as suggested by Ankney (979) and Prnce (979). Increased daylength was assoeated wth nereased restng on the feedng grounds by whte fronted geese (Anser albfrons frontas)(owen 972). Inereases n the average number of hours spent restng n late sprng by both speees were greater than ncreases n dayght hours. Folk (97) eonsdered that tme spent restng by the tufted duek was nversely reated to the tme spe.nt fotagng Contrary to ths tme spent restng by lesser caup ncreased sgnfcantly n late sprng athough tme spent feedng dd not decrease suggestng that tm spent. restng may be nversely related to other actvtes. McKnney (965) has hypotheszed that nterna stmul such as a fu crop reduce the tendency to feed alowng other tendences to be expressed. Comfor movements generally follow feedng n waterfow (McKnney 965 Nsson 974 Segfred 974). Tme spent preenng was greater n la te sprng than ary sptng for both speces of Bcaup however tme spent feedng n late sprng decreased for greater seaup but (!>&

37 '-.....U; t''''_ 6 ( ) not for esser scaup.. 26 Ths would suggest that t spent feedng and q Ume spenrpreenng are not drectly related to eàch other. The fact that tfemae reàter and lesser 8CUp preened more than males throughout the sprng 8 a reflecton of heaver body feather malt n females (Table 0). Heaver malt n female greater scaup durng Marc and Aprl' has also been demonstrated by Bllard and Humphrey (:.972). Segfred t. - (974) aso found tat durng sprng mgraton ld8e lesser rscaup spent ess tlde preenng than females.! l j } j Actve swmmng by waterfqwl may be due to dbturbance searchng for food seekng a potental mate or engagng n courtshp. In preparaton for n.ght scaup sw!m n the drecton of take-off whle pero formng chn-lftng (Johnsgard 965). Restng and feedng brds were freqùontly carded.fr... a flock by the cuttent and would pedodully' swm back. Decreases n frequences of swmmng by greater and lesser scaup n late sprng may be nfluenced by the lower number o unpared males present. The result should have been that fewer males vere searchng for and competng for mates and females thus spent less tme avodng unpared males. Segfred (974) found that courtshp behavour - by lesser scaup was normally ntated by unpared males. More Ume speqj: courtshp by unpared brds was als-o observed n rngnecked ducks (Aythya collads) by Mendall (958). Courtshp by greater and lesser scaup was occasona!ly performed br pars but was most frequently observed n courtshp groups consstng of or 2 females and severa! males. Often brds would dve n unsonor make occasonal o courtshp flghts but most actvty conssted of swmmng and dsplayng. (

38 .' -- ho... LI.. '); '.. ' _ LXI t ra.i... 'Il t!i. () D:splays:- are dèacrfled Dy Jobnsgl;lt'a (965). Pre-flght swmm:l.ng aso 27. r decreased as a result of less t:bœ spent flyng n late spr:tng. Estmatng the a'munt of daylght spent fyng s extremely dffcult l as blrds dsappear from sght and are no longer Dcuded n further behavoural;. observatons. Understandng trends n the SDIOunt of flyng done la mportant partcularly n constructng ener-gy budgets as flght s the IIOst metabolcally expensve actvty that ducks engag tn (Wooley and OWen 978). Great:r and lesser scaup showed sgnfcant decreases. n tme spent flyng n late sprlng. As br become falllaj- w-th the lak ess tme s requred to seek feedng and retng areas spent flyngsbould decrease. The fact that more males were (o fiyng than feules throughout the sprng la kely because unpared males were seekng potental mates. Segfred (974) aso fot.md that unpared { '. male lesser scaup spent more tme flyng than pared males or females. In the present study t was generally mp08sb to dstngush between pared and unpard males howeve'r sngle males and small groups of males were frequently observed flyng wthout accodlpanyng females. Nocturna feedng habts of ducks durng the fall and wn ter have been noted for severa speces (OWen 90 Nlsson.970b Thornburg 973 Tamser ). Tamser ( ) suggested that durnal gregarousness and 'nocturnal feedng by CODllOOn teal- (Anas creees. crecea) a prmarly an adaptaton to predon pressure fac:tl!tated by other factolts. ) Contrary to ths Thornburg (973) feels that dvng ducks adapt to huntng dsturbance by devatng fram typca patterns of d.urnal actvty. ( Mal.lards have been shown to change feedng routnes n response to huntng (G.rard 94). Increased nghttme feedng n response ta huntng s

39 ... _-- - J d..!... _.IIItN.ll'IIb.F_' _lii!;mi'_itli_... () dso seen n geese _ (Owen 972 Newton and Campbell 973). Huntng and recreatonal actvty on Lake St. Lous dd frequently nfluence the tmng and magntude of dvng duck fghts but ncreased durnal actvty dd not océur as human dsturbance decreased late n the fau. However as Owen (972) has ponted out n the caselof -geese not ooy - actual dsturoance but also the tradton of dsturbance n an area'wll nfluence behavour: 28!. o Condton and Phylogy Weght gan by mgrant brds n the fom of atored lpd reserves a aécomplshed by actve hyperphaga (Kng 97). There are two dstnct sourêes of lpds for storage: absorpton of lpds n foods from.. the ntestnal tract and aynthess from: nqn-lpd compounds (Grmnger 976). t#: Once lpd stores approach alartcuar maxmum t a necessary to reduce food ake unless an ncrease n energy output occurs. Excessve resèrves ar envronment ncrease he. maladaptve as they are Jjbtaned at the expense of the rsk of'predaton and are metabocally expensve t mantan (Helms 968. As'lpd stores ncrease bulk and qenèe--drag of the' body n flght ncreases resultng n a decreased / effectve lft:drag rato (PennYcuckl969). Ths < obvously a consderaton for long dstance mgrants. Greater sc;aup gned sprng mgratory perod. weght' and ncreased fat reserves OVE!r the Th fact that weght ocreases n la te sprng )!! j! () o by greater scaup were not sgnfcant may suggest that maxmum reserv. levels were areadybeng approached by a large proporton of ndvdualsf n the early sp.rng perod. Less tme spent feedng n lat!! sprng dso suggests ths. Mean body weghts of late sprng greater scaup (Table 4).- -

40 ... ut m.a ' _ '---.4._._ p- xœ.... _._--/ F) J! 29 are hgh.er than DOst provded n the terature for mgratng or wnterng t brds (Nelson and Martn 953 Ryan 972 Jobnsgard 975; Palmer 976 Belrose 976). Large ncreases n mean body weght would therefore seem unlkely. A s:8fcant dfference between body weghts of early and f!ste sprng greater scaup mght have ben found f brds could have been v collected when' the ce bêgan to break. up and the earlest arrvais were seen on Lake St. Lous. These brds started to arrve approxmately 2 weeks before collee tng coud he s tarted and tnerefore had Ume to bud up pd reserves. Mean proten and fat-free wegh.ts were not sgnfcantly hgher n ate sprng male greater scaup athough slghtly hgher values n late sprng brds especaly adult femaes and juvenles suggested some () proten storage W8S occurrlng. Fry.!:! al. (970) have shawn that fa-free weghts.ncreased durng the frst few days of pre-mgratory hyperphaga. l Sgnfcant changes n proten and fat-free weght n greater scaup may have been ebtaned f DIOre early arrvas had been collected. Pro tens stored prer to and durng mgraton may be used durng perods of mgratng flght when detary ntake of carbohydrates cannot supply the oxaacetate requred for fat metabolsm. Hanson (962) states that a brd cannot use ts fat deposts durng mgraton or durng perode of starvatlon wthout a smultanec>us use- of body proten. Peterson and Ellarson (979) found that pd and proten levels fluctuated together n wnterng oldsquaw (Cangula hyemas). Scaup arrvng at Lake ( St. Lous have used fat reserves to fuel mgratory flght and n the ( poce88 have presumably drawn on proten stores. As fat reserves are replenshed durng the stopover protens pent on fat metabolsm must

41 -- M '_mn._._wl. u ( _ l ()..-'. - a80 he repaced n preparaton for her fght. 30 As well as ncreases of stored fat lesser scaup exhbted hgher r:en and fat-free weghts n ate sprng. Increasès may n part be explaned by the arser sze of bresst muscles and some dgestve organs. ' Heaver breast muscle may reflet ; use durng mgra tory flght suggestng that brds arrvng later n the sprng may have f0wn a longer dstance than eare arrvais. Breast muscles may be major storage organs for prote'n needed to metabolzé lpds durng mgratory flght. Kendall.!! al. (973) have shown that prten from the breast muscles of Queles quelea s lable and used elseere: Increased lpd content of C) -. the breast wll occur as body.lpds are tored however data from - Ravellng(l979) sh that changes n lpd content can account for only part of changes n the!eght of the entre breast. 'lhe 'dstance that Oude fown'by late sprng greater scaup can be calculated. Applyng the mean body weght of é!.dult males. n late sprng ta ;e equaton provded by Owen and Renecke (979') basal metabolc rate (BMR) s calculated as: BMR - 75 (.4) kcal day-l Multplyng ths value by 2.5 the multple of BMR expended urng fght (Wooley and Owen 978) the cast of nonstop fyng Is calculated as - approxmately 03.3 kca clay To determne the kcals avalable n stored lpds totaable fat weght s multpled by 9. kcal g-l the calorc densty of fat stored by mgratory'brds (Jonnston 970). Grmnger (976) states that even at the tme of starvaton to death a small percentase of body weght s made up of fat therefore total fat weght do es not equal the weght of fat avalable or metabosm. Wshart (979) has shown that total lpds n starved Amercan wgeon

42 J ; js4 --:--- 3 '(Anas amercana) are less than % of body weght at death. Starvaton weghts of male greater scaup are not known but presumaby are n tbe are a of 800 8; therefore the weght of total lpds at death would be pproxmately 3 g. The mean weght of avalable stored lpds would then be 200 g whch wll provde 820 Kcal of energy enough for.8 days of nonstop flyng. As waterfowl mgrae at an average speed of 80 - ' km hr (Bellrose 976) the average nonstop dstance late sprng male 8rater scaup can fy s approxmately 3500 km. Thè dstance to major breedng areas from Lake St. Lous s 4000 km or more (Berose 976). Although some brds could possby fly nonstop to the breedng gounds () they would arrve exhausted of lpd store's and would possbly be ncapable of reproducton. However JOOst brds would not be able to fy the dstance to the breedg grounds. These dstances are based on a --' calore dénsty of st0l'ed-lpds of 9. kcal g based on burnng. The actual energy e.valable to a brd durng lpd metabolsm may be lower; therefore the dstances calculated above may be an excess of what could be attaned. Applyng the same logc to late sprng male lesser scaup a value of keal day s obtaned for flght and 490 kcal s the energy Q avalable from stored lpds. Late sprng male lesser scaup can therefore fly nonstop for approxmately.8 days and for a dstance of 3500 km smlar to that calculated!or greater scaup. Major br'eedng areas begn less than 2000 km from Lake St. Lous although mportant breedng grounds ll Alaska and the Northwest Terrtores are stll farther than could be reached by tb majorty of less-er {caup. Early sprng male lesser scaup could on average fly.3 days and cover a dstance of '.--:-{t-=. -..-_... '..._!'

43 32 km. Ravng reached the breedng grounds n Mantoba o Saskatchewan lpd stores would be depleted. The mportance of stopoveràrea8 to. greater and lesser scaup for replenshng spent body lpde s therefo evdent. The number of days'requred ta replensh endogenous lpd reserves for gratory waterfow weghng 00 g has been calculated.by Fredrckson and Drobn.A (979) for varous dstances flown and calore! d ; ( ntakes. The amaunt of tme needed to replensh reserves wll be affected by several factors such as the condton of brds arrvng. the qualty nd. quantty of the fa pd resources at the stopover area and weather. C) The average duraton of stay by scaup on Lake St. Lous was not determned. Several studes on galnaceous brd have shawn that the sze of dgestve organs s nfluenced by det qualty (Leopold 953 Lewn 963 MOss Pendergast and Boag 973).' More recent works have ndcated that changes n the gut are-more key the result of changes n food consumptor whch may vary n response to det quaty (Fenna and Boag 974 Mler 975 Savory and Gente 976a b). Ankney (977) has shawn that changes n feedng actv!ty by lesser snow geese ( caeruescens caeruescens) are postvely correldted wth changes n the average sze of dgestve organs. - As mgratng brds are constanty faced wth varyng habtat and food resources changes n the gut should be made to rapdly accommoda te Fhanges n food take qualty. Mller (975) showed that malrards changng from a low fbre (' to a h3h fbre de( exhpted ncreases n dgestve organ sze and ( -- 't' wthn 3 weeks. F '

44 _._ _._- ; - 33 ( ). ' Although a decrease n feedng rates by grater scaup was observed '-' n late sprngoy' large ntestne ength showed a sgnfcant decrease: In redheads (Aytnya amercana) large ntestne!enàth and weght show strong curvlnear correlatons wth seasona! feedng patterns whereas gzzard weght and small ntestne and caecum weghts and lengths ar no sgnfcanty correlated (Baey 982).' The equaton predctng large ntestne length n redheads fram tme spent feedng (Baey982) was appled to data for greater scaup. Caculated large ntestne lengths for adult males n eary and ate sprng are 9.6 mm and 84.7 mm respec f tvely. Observed values were 92.0 mm and 84. mm. Predcted values o for adult females are 93.2 mm and 82.8 mm; observed values were 93.0 mm and 85.3 mm. ) The fact that the wetght of the large ntestne dd not appear to respond to feedng rates s dffcult to explan. Several authors have shown that gestve organs may be used for proten storage (Ankney 977 Korschgen 977 Baley 982). Proten from thé walls of the ntestne 'may have been tsed to supply needs for lpd catolsm resultng n ntestnàl weght 0ss durng mgraton pror to arrvai at Lake St. Lous. Increases n ntestnal ght y have occurrer shortly after arrvai n the earlest part of the sprng before l was abte to obtan samples. If the ntestnes are beng used as a proten reserve for mgra tory flght then the weght should not respond to changes n food ntake and should! not decreàse as the frequency of feedng decrease. Sample szes of juvenles are small however slghtly hgher mean values for ntestnal weghts and lengths suggest that food ntake may not necessarly parallel that of adults. Dfferences n chronology of mgraton and n behavjuwll affectme spent eedng and food Intake. /.

45 T î ( Studès deatng wth the gut have prmarly used length as the l' measurement of change (Lewn Moss Pender8!lst and Boag Savory and Gentle 976a b Ankney 97.7). Mller (975) found tbat. the weght of the gut was nfluenced by' detary fbre and ncreased concurrently wth length. Late sprng adult esser scaup exhbted large gans n small and large ntestne weght w:l.thout concurrent changes 'n...j length. ' The lack of change n large ntestne length. agrees wth the smar feedng rates observed n eary and late g. The weght measures do not seem to b related to feedng rates suggestng that J! proten was beng stored n th ntestnes ta replace what W8S used for. o.. the degradat0n of pds durng mgra tory flgnt. Lewn (963) found that the ntestnal vll of Calforna qua! (Lophortyx eaforncus) lengthened n response to low quaty ulky foods wheh woud presumably result n a hgher ntestnal weght. How-. ver ncreases n vll length were 'ccompaned by longer small and large ntesdnes and longer cacae. Lesser scaup showed a hgher 'weght:ength rato n the ntestnes suggestng enhanced effcency. Bretenbach al. (963) found that pbeasants Phasanus coehcus) on a proten restrcted det showed an ncrease n ma ntestne weght presumably to enhance proten upake from àvaabe food. Increases n proten wegbt and breast muscle weght may have requred enhaneed proten uptake by the ntestnes. Inereases n proten over the sprng occurrng concurrenty wth ntestnal weght ncreases may also suggest proten storage n tese dgestve organs. The faet that gzard weght does not change along wth the weghts of tbe ntestnes s puzzlng as ths organ - s beeved to' be a proten reserve (Ankney 977 Korscbgen 977 Baley j (

46 '_'_' I_I._... _._. J. '''''tltll''''.''''''''i_j $_....' 35 dl'...(... ;...._ ) Dgestve ouan measurements taken on the wnterng grounds before. J and durng premgratory hyperphagawth concurrent IlOntorng of feedng ' rates would provde more nslght nto changes n the dgestve organs. Measurements of food consumpton would provd loore relable data to.. explan changes tn dgestve organ sze. Tme spent feedng may ncrease l f 0wer qualty foods are consumed. Gadwas exho.ted ncrases n tme spent feedng concurrent wth declnes n most gut measurements ndcatng that feedng actvty reflected a change n det and can not! î j f '! entrey expran changes n gut sze (Paulus 982). Although food consumptdn can be montored for captve brds such nformaton s dffcult f l to obtan for free lvng brds. The use f stopover areaa aucn as Lake St. Lous for nutrent replenshment by greater scaup mgratng n the fall s ndcated by heaver body weghts n late season ndvduals althobgh certan varaton between years was ndcated. Contrary to ths body weghe ncreases n Il lesser scaup dd not always occur over the fal. Dstances between stopover areas may be shorter n the fal resultng n less weght 088 l y between stops. Body weghts of early fall adut males n 980 ndcated that fat and proten reserves had already been replenshed n many brds. lt s not possble to say whether these brds had arrved here fat or f ncreases n weght occurred durng the stopover at Lake St. Lou. Smlary body weghts of eary and ate fal juvenle esser scaup were not dfferent from each other n 979. Mean body weghts over 700 g' ndcate that many early juvenles had already estabshed substanta ' reserves n early fall. An eamnaton of rœw daa reveals that -. - n the late fall perod of 979 there were many low weght brds whch were } ) l'

47 - 'tlt () presumably late arrvais. The varaton n body weghs s ndcâted. by the hgh standard errors assocated *th them (Table 9). A later 36 mgratonby!some brds may ndcate regonal dfferences n tme of nestng or May be weather-relted. Contour Feather Malt 'The extent of molt n greaer scaup generally agrees wth the resalts of Bllard and Humphrey (972). The majorty of both adult and Juvenle ' males appear to have completed the pre-alterqate molt by the tme the sprng mgraton s underway. Bllard and Humphrey (972) found that 20% of Juvenle males were stll exhbtng lght molt whereas n the present study no molt was observed n ths age-sex class. The excluson / o of the scapulohumeral feather tracts n the present study May have cont trbured to ths dscrepancy however l would ekpect that the maneason!. Is that the majorlty of Bllard and Humphrey's (972) samples were collected n Connëctcut. Brds from that area would not be as advanced nto the sprng mgraton and many may not have evep begun the northward journey. Results of the present study and those of Bllard and Humphrey (972) ndcate that the majorty of female greater and lesser scaup are weil nto the pre-basc malt durng the'raton and that these 2 energy demandng events are not separated n tme. Overlaps of energy demandlng events may be attrbuted pressures of tme or shortages of nergy (Kng 974). Although molt Is consldered an energy demandng functon (Bllard and Humphrey 972 Kng 974) t s occurrng durng another energy demandng event namely mgraton and durng a pérod of nutrent storage. There 8 obvously no nutrtonl 2 stress on females at f

48 / / SA'. Il ç' t' ( o. f ':::'- 'd () ths tlle. llowever ncreased food ntake or adjustments n tme-actvty 37 budgets mae necessary for molt and mgraton to occur smutaneoualy. / () '.' ()

49 ( ) CONCLUSIONS 38.J -Grea ter and lesser scaup are utlzng topover areas such as Lake St. Loûs as feedng and restng areaa durng the course of mgraton. Changes n behav0ur over the mgratory perod appear to be nfluénced by levels of stored lpds n the brds the rato of males to females and the brds famlarty wth the area and possble changes n the. food resource. Durng the sprng both speces exhbted ncreases n storea lpds. Calculatons of flght ranges based on levels of stored lpds n sprng brds show that scaup have to replensh lpds used durng c mgraton to reach the breedng grounds n good condton. Hgher proten levels n late sprng brds ndcated that pro tens were beng accumulated. concurrently wth lpds. changes' n-dgestve organs could not be clearly explaned by changes n feedng raes. Dgestve organ changes May be related to proten storage and functonal changes n the gut. (

50 _I I.e t.. ' GIN l. _ d. le '-ll. IRllll mrth _ LITERATURE CITED Afton A.D Tme budget of bree4ng northern.shoelers. Wlson Bull. 9: Atmann J Observatona study of behavour: Sampng methods. Behavour 49: '- j l y C.D Feedng and dgestve organ snow geese. Auk 94: S' breedng lasser Ankney C.D Does the wng molt cause nutrtonal stress n lesser snow geese? Auk 96: Batley R.O The postbreedng eeology of the redhead (Aythya amercana) on Long Island Bay Lake Wnnpegoss Manrtoba. Ph.D. Thess. McGll Unv. Montreal. 30 pp. Barr A.J. J.H. Goodnght J.P. SalI and J.T. Helwg S.A.S. User's Gude 979 Edton. S.A.S. Insttute Inc. Ralegh N.C. Berose F.C Ducks geese and swans of North Amerca. Pp Stackpole Books Harrsburg Pa. Belrose F.C. and A.S. Hawkns Duek weghts n Illnos. Auk 64: Bent A.C Pp Lfe hstores of North Amerlean wld fowl. Dovar Publ. N. Y. Part. Bllard R.S. and P.S. Humphrey Malts and plumages n the greater scaup. J. Wldl. Manage. 36: / Bretenbach R.P. C.L. Nagra and R.K. Meyer Effect of lmted food ntake on eycle annual changes n rng-necked pheasant hens. J. Wldl. Manage. 27: Calverly B.K. and D.A. Boag Reproduetve potental n parklandand aretc-nestng populatons of malards and ptntals (Anatdae). Cano J. Zoo. 55: Chappell W.A Estmatng reserve lpds n greater scaup (Aythya marla) and lesser seaup (!. affns). M.Sc. thess paper. MeGl Unv. Montreal. (./'

51 --_...--._..._ Î! '. Le ( l Dwyer T.J :335.!.343. Tme budget of breedng gadwalls. Wlson Bull. Dwyer T.J. G.L. Krapu and D.M. Janke Use of prar.e potlole habtat by breedng mallards. J. Wldl. Manage. 43: Erkne A.J. 97. Bufflebeads. Seres No. 4. Ottawa. Canadan Wldltfe Servce Monograph Fenna L. and D.A. Boag. 94. Adaptve sgnfcanee of the caeca n Japanese qua! and spruce grouse (GalUformes). Cano J. Zool..52: Folk C. 97L A study on durnal aetvty rhythm and feedlng habts of Aythya fulgula. Prrodoved Pro Ustavu. Cesk. Akad. Ved. Brne. Acta. Sc. Nat. Brno. 5:-39..I......_$ll... ''' _IIItt-..._H l Folk C. K. Hudec and J. Toufar The weght of the mallard Anas platyrhynchos and ts changes n the cours.e of the year. Zool-. Lsty 5: Fredrckson L.H. and R.D. Drobney Habtat utzaton by postbreedng waterfowl. Pp. 9-3' n: T.A. Bookhout ed. Waterfow and wetands: an ntegrated revew:- Proe. 977 Symp. Madson WI N. Cent. Sect. The Wldlfe Socety. Fry C.H. J. S. Ash and l J. Ferguson-Lees. 90. Sprng wegh ts of some Palearc tc brds a t Lake Chad. Ibs 2: Grard G.L. 94. The mallard: ts management n western Montana. J. Wldl. Manage. 5: Gravel Y. and Fr. L. Lévesque. 97. Localsaton e: cartographe de zones d'herbers du fleuve Sant-Laurent. Mnstere du 'toursme de la chasse et de la peche. Rapport technque no. '. ) Grmnger P Lpd metabolsm. Pp n: Avan PJlYsology P.D. Sturke ed. Sprnger-Verag New York. o'.--' Hanson H.C The dynamcs of condton factors n Canada geese and ther relaton to seasonal stresses. Aret.' Inst. North Am. Pape No. 2. Hrrs H.J. Jr. wnged teal Evdence of stress response n breedng 'blue J. Wldl. Manage. 34:4-55. Helms C.W Food fat and feathers. Amer. Zool: 8:5-67. ( )

52 c. Q Hckey 'I.E. Jr Aetvty bud8ets and movements of Black. Ducks (Anas rubrpes) n Prnce Edward Island. M.Sc. Thess'. McGll Utrl.v. Montreal. Hll F.V. and L.M. Dansky Studes of the energy requrements of cb:f:ckens.. The effect of detary energy evel on grow.th and feed consumpton. Poult. Se. 33:2-9. Hochbaum H.A. 944.' The eanvasback on a prare marsh. Amer. Wdl. Inst. Washngton. 20 pp. Johnsgard P.A o-handbook of waterfow behavor. Pp Cornell Unv. Press. Ithaca and London. L;fb Jobnsgard P.A /Waterfow of North Amerca. Pp Indana Un.v. Press. Bloom:J:ngton l:uld London. a Johns.ton D.W Calore densty of avanadpose tssue. Comp. Bochém. Phys0. 34: Kendall M.D. P. Ward and S. Bachus. 93. A proten reserve n the pectoras majof fght muscle of Quelea quelea. Ibs 5: Kendegh S.C. V.R.oDolnk and V.M. Gavrov Avar energetcs. Pp n: Granvorous brds n ecosystems. J. Pnowsk and S.C. Kendegh eds. Cambrdge Unv. Press. Kng J.R Adaptve perodc fat storage by'brd$. Int. Ornth. Congr. 5: Kng J.R Seasona allocaton of tme and energy resources n brds. Pp n: Avan energetcs. R.A. Paynter ed. Nuttall Ornth. Club Publ. l5. Cambrdge Mass. Klma M A study on durna actvty rhythm n the European pochard Aythya ferna (L.) n nature. Zool. Lst Y 5: Korschgen C.E. 97. Breedng stress of female eders n Mane. J. Wld!. Manage. 4: ortrght F.H The ducks geese and swans of North Amrca. Pp Stpoe Harrsburg Pa. and Wld!. Manage. Inst. Washngton l. c.. Krapu G.L Feedng ecology of pntal hens durng reproducton. Auk 9: Krapu G.L. 98. Auk 98: The roe of nutrent reservesl n mallard reproducton. (

53 .' ( )... Leopold A. S In tes tna Up.Phoogy of gallnaceous b rds n relaton to food habts. J.ldl. Manage. 7: j... ) :j!. ' Lepkovsky S. 973 Hypothaàmc adpose tssue nterrelatonshps.. Fed. Proc. 3: (. Lewn V Reproducton and development n a populaton of Cafoma quaj. Condor 65: McDonald f. R.A. Edwards and J.F.D. Greenhalgh. Olver and Boyd Ednburgh. 479 pp 973. Anf!lal nutrton. M<;.Knney F The coort movements tdae. Behavour _ 25: Mcaness M.R. and D.G. Ravelng. 98. Changes n det and body composton of Canada geese before sprng mgraton. Auk 98: '9- Mendall H.L The rng-necked duck n the northeast. Unv. of. Mane Bull. 60(6). 37 pp. Mller K.J Actvty patterns vocalzatons and ste selecton n nestng blue-wnged teal. Wldfowl 27: Mller M.R. qualty Gut morphology of mallards n relaton to det J. Wldl. Manage. 39: MOSS Effects of captvty on gut lengths n red gro4se. J. Wldl Manage. 36: 'Moss R: 974. Wnter dets gut lengths and nterspecfc competton n Aaskan ptarmgan. Auk 9: Nelson A.L. and A.C. Martn Gamebrd weghts. ;J. Wld. Manage. 7: Newton. and C.R.G. Campbell Feedng or geese on farmland n east-central Scotland. J. Appl. Ecology 0: Nlsson L. Swecen. 970a. Non-breedng ecology of dvng ducks n southernmost Ph.D. Tbess. Unversty of Lund. 70 pp. Nlsson l. 970b. FObd seekng n the non-breedng season. o c - Nsson L.' 974.' 'the behavour WldfQwl 25: actvty of sou Swedsh dvng ducks Okos 2: J of wnterng smew n northern Sweden....

54 ...' _ ----.:-*-.--I (. ) Owen M Some factors affectng food ntake n whte-fronted' geese. J. Anm. Eco!. 4: Owen R.B. Jr. 970: The boenergetcs of bluenged teal under controed.and outdoor condtons. Condor Owen R.B. Jr. and K.J. Renecke Boeuergetcs of breedng dabblng ducks. Pp !!!: T.A. BQokhout ed. Waerfow and we tands : an u tegra ted ev:tew. Proc. 977 SylIIp. Madson WI N. Cent.' Sect. The Wdltfe Socety. Pageau G. and L. Lévesquè Les herbers du lac Sant-Lous: composton repartton et dynamsme en rapport avec l'habtat du sknouge. Serv Faune du Quebec. Rapport no. 3. Palmer R.S Handbook of North Amercan brds. Vol. 3. Pp Yale Unv. Press 'New Haven. Paulus S.L Gut morphoogy of gadwalls n Lousana n rnter..j. Wld. Manage. 46: Pendergast B.A. and D.A. Boag Seasona changes on the nterna anatomy of spruce grouse n Alberta. Auk 90: A J } j f!! J - l Penny cuck CJ The mechancs of brd mgraton. Ibs : Peterson S.R. and R.S. Ellarson weght. Wlson Bull. 9: Changes n oldsq-qaw èarc8ss ' Prnce H.H Boenergetcs of postbreedng dabblng ducks. Pp n: T.A. Bookhout ed. Waterfow and wetlands: an ntegrated revew. Proc. 977 Symp. Madson WI N. Cent. Sect. The Wldlfe Socety_ Ravelng D.G The aunua cycle of body composton of Canada geese wth specal reference to control of reproducton. Auk 96: Ryan R.A Body weght and weght changes of wnterng dvng ducks. J.!N'dl. Manage. 36: Savory C.J. andm.j. Gentle. 976a. Effects of detary dlutonwth fbre on the food ntake and gut dmensons of Japanese qual. Br. pout. Se. 7: ! Savory C.J. anp M.J. Gente. 976b. Changes n food ntake and gut sze n Japanese qua n response to manpulaton of detary fbre content. Br. Poult. Se. 7: ( Segel S. 9S. Nonparametrc statstcs for tqe behavora scences. McGraw-H N. Y.

55 44 r j J - Seymour N.R. and R.D. Ttman Changes' n actvty patterns agons tc behavor and terrtoralty of black ducks (Anas rubrpes) durng the éreedng seasqn n a Nova Scota Udal marsh. Can. J. Zoo. 56: Segfred W.R Tme budget of behavor among lesser scaups on Delta Marsh. J. Wldl. Manage. 38: Segfred W.R. A.E. Burger and P.R. Frost. for breedng n the maccoa duck. Ardea 976a. Energy requrements 64 : l7-9. Segfred W.R. A.E. Burger and F.J. van der Merwe. 976b. Actvty budgets of male maccoa ducks. Zool. Afr. :-25. P- Skead D.M. 97. Durnal actvty budgets of Anatn! durng wnter. ' Ostrch Suppl. 2: l! l Î 4 ll l Smth K.G. and R.H. Prnce 'The fastng metabolsm of subadut malards acclll8tzed to lowambent temperature. Condor 75 : Stewart G.R. and R.D. Ttman. pothole blue-wnged tea <Terrtoral behavour by prare Cano J. Zool. 58: Tamser A Sgnfcaton du gregarsme durne et de a' almentaton des Sarcelles Anas E. crecea (L.). Terre Ve 970: Tllmser A Etho-ecoogca etudes of tea wnterng n t Camargue. Wldfowl 25: / Taml!er A. :976. Durnal actvtes of green-wnged tea and pnta! wnterng n Lousana. Wldfow 27:9-32. Thornburg D.D. 93. Dvng duck movements of Keokuk pool. J. Wldl. Manage. 37:3& L.. Ttman R.D. 98. A Ume budget for breedng malards (Anas patyrhynchos) n Mantoba. Cano Feld. Nat. 95: Weller. M.W Growth weghts and Plumasef the redhead amercana. Wlson Bull. 69: Wshart R.A Indces of structural sze and condton of wgeon (Anas amercana). Cano J. Zool. 57: Aythya Amercan Wooley J.B. Jr. and R.B. Owen Jr Energy costs of actvty and day energy expendture n the black duck. J. Wldl. Manage. 42: Wypkema. R.C.P. and C.D. Ankney Nutrent reserve dynames of lesser snow geese s tagng a t James Bay Ontaro. Can. J. Zo : '

56 ::_:::...:...;;...;.. 't..;_...;... r '.' ( ) 45 Table.' Ratos of males per female n greater and le88er' scaup durng sprng mgrat:f.on on Lake St. Lous 98Q March 23- March 25 March -26- Aprl 3 Aprl 4- Aprl 3 Aprl 4- Aprl 2 Aprl 22- May Greater scaup ! ( ' ' '..

57 . ('-;-' ('...;..-. c- - - : - - Table 2. 'a Percentages of greater scaup perfrmng varous actvtes durng daylght hours n early and late sprng and mean hours per day spent by each dùck n these actvtes '' 'l- Feed Rest Preen Swm - Fly; Earl} Late Early Làte Early Late Early Late Eary Laj:e (3.56)b (2.95) (2.97) (5.26) (.59) (.89) (4.97) (4.44) (0.72) (0.36) Males 25.8 c ** ** N.S ** ** 2.4 * N.5. ** * ** ** ** ** ** N.S. Females 27.4 ** ** * ** **.5 (3.78) (2.73) (3.44) (5.84). (2.46) (3.07) (3.73) (3.02) (0.40) (0.22) aaverage number of daylght hours (from 0.5 hour before sunrse to 0.5 hour after sunset) n early sprng 3.8 and n late sprng B 4.9. b Numbers n brackets are mean numbers of hour pe day spent by each duck n eacb actvty. c ' Percentages of ducks observed performng each actvty. f' *P<0.05. statstcal sgnfcance determned by ch-square test-on raw totals. **P<O.Ol statstcal sgnfcance determned by ch-square test on raw totals. - : j r -; N.S. No sgnfcant 4fferenc determned by ch-square test on raw totals..r: a> -..e....:lool

58 w o_... _ w '-' J r-. o t' '- -. -l!!.. -' Table 3. Percentages of essecaup performng varous actvtes durng dayght hqurs n earya and làte sprng and mean hours per day spent by each duck n these actvtes. Feed Rest Preen Swm Fly Early Lat EarJ... Late Early La te Early Late Early La te (2.l9)b (2.5) (3.72) (6.27) (.40) (.87) (6.44) (4.05) (0.57) (0.4) Males 5.3 c N.S ** ** : ** 26.8 ' 4.0 ** 2.7 *l * ** N.S. ** ** ** ** ** **' Femae 7.5 N.S 'le 'le ** 27.4 ** 9..7 ** 0.8 lj -(2.50) (2.87) (5.38) (6.24) (2.26) (3.00) (3.92) (2.88) (0.24) (0.2) I- l l. a -Average number of dayght ' hours (from 0.5 hour before sunrs to 0.5 hour after sunset) n early sprng and n late sprng b Numbers n brackets are mean numbers of hours per day spent by each duck n each actvty. c Percentages of ducks observed performng each actvty. *P<O.05. statstcal sgnfcance determned by ch-square test on raw totals. **<O.Ol. statstcal sgnfcance determned by ch-square test on raw totals. N.S. No sgnfcant dfferènce determned by ch-square test on raw t9tals.... -f _ --_._ ; _ _._

59 )' 'j r--- --; ' ! Table 4. Comparson of body parameters a St. Lous Quebec of early and late sprng mgrant greater scaup collected at Lake Male Female Adult _Juvenle b Adult _Juvenle b Parame ter :t SE (N) Je t SE (N) t SE (N)b X ± SE (N) 7.. ''' Body weght Early :t23.28 (7) 902.5:tlO.5 (2) () () Late -- ll4.39±28.73 (6) ±48.47 (4) 0.60±33.35 (3) () r Breast muscle weght Early 89.79:!:. 2 (7) 82.05:!: 2.43 (2) () () Late 9.47± 2.05 (6) 93.42t..5 (4) 90.52:t 3.87 (3) () Leg weght ) Early 43.58:!:.9 (7) 39.± 0.98 (2) () 4l53 () Late 44.ll± 0.67 (4) 4l.7±.05 (4) 40.32± 0.34 (3) () Gzzard weght Early 49.38± 2.9 (7) 46.44:!:.63 (2) 37.2 () () Late 46.02± 2.09 (6) 46.8B± 48 (4) 43.6t.46 (3) () Small ntestne length Barly (7) ±59.00 (2) 62.0 () ().;.f Late 65.9 ±37.42 (6) ±27.29 (4) t.24 (3) ().. 00 Contnued '--' -' _ t odl t_' ! ' -- -

60 .'. r-'._' '.-....:J J '- :.. fl :! 'v(-. (.' 7W' '. ' '.' Table 4 (Contnued) Parame ter 58 ntestne weght Early Lat Adult ± SE (N) 2. 22±. 38 (7) ' f Male 2l.2l.54 (6) _Juvenle'b x ± SE (N) 9.23± 0.9 (2) 2. 77j:.36 (4) _ Adult b ex ± SE (N) 26.7 () 2.56±.68 (3) Femae _Juvenle b X ± SE (N) 5.8 () ().. Large ntestne length Eary Late 92.0 ::!:.23 (7) 84. ±.86 (6) tr:lr 86.0 ± 2.00 (2) 89.3 ± 3.68 (4) 93.0 () 85.3 ± 6.0 (3) 8.0 () 83.0 () Large ntestne wegbt...f Early Late. 79± 0.06 (7). 92± 0.3 (6). 50± 0.05 (2) '(4) 2.36 () Z (3) _. 36 () 2.86-() Combned ceca length Early Late ± 9.23 (7) ± 5.44 (6) (2) ± 7.9 (4) 27.0 () ± 7.23 (3) () () Combned ceca wegbt Early Late l.ls± 0.08 (7).7::!: (6).04± 0.-l8 (2) (4)..35 ().40± 0.02 (3).3 ().47 () ;: 'r ti;... t- II j t ):-.. r:.: '''''I.... *>!'... c9 le 'év?l'suc? - - ''';ft Cotnued D!

61 --... o ----' Table 4 (Contnued) / Male _ Adut _Juvenle b Parameter x ± E (H) x ± SE (H) Adult b ±SE (H) Female _Juvenle b x ± SE (H) Skn weght Early Late f 27.83t4.26 (7) * 26.56±3.2 (6) 44.00t 2.93 (2)! ±39.29 (4) 2.64 () ±2L08 (3) () () Abdomnal fat eght.. Eary La te v ntestnal fat wegbt Early La te 9.l6±.39 () l8.2± 2.65 (6) ' 6.2t.06 (7) tc 2.ll± 2.04 (6) 2.66± 0.20 (2) 4.37± 4.56 (4). 75± 0.5 (2) 9.68± 2.59 (4). 79 () l6.30± 6.46.(3) Il.23± 3.50 (3) e 3.57 () 5.99 () 0.35 () () '-.J Total fat welght Early Late 42.35±4.63 (7) 203.7±7.25 (6) 56.l2±.94 ( 7. 70:!:44.86 (4) () 78.4!±39.85 (3) () () Contnued VI o -.. -:; tt«n-'«'pr. c..._...

62 j - o ' ) '... _ '... c'... l Table 4 (Contnued) Male o _ Adult _Juvenle b _ Adult b _Juvenle b Parame ter x ± SE (N) x ± SE (N) x ± SE (N) x ± SE (N) c Proten.weght Early La te 25.23± 2.75 (7) 2l9.09± 4.44 (6) ± 3.45 (2) 2. 7± (4) 94.4 () ± 3.50 (3) () 99.5 () '.l Fatfree Early Late carcasa weght 755.l7±ll.8 (7) ±47 (6) 7l6.73± 6.4 (2) ± 9.75 (4) () ± 8.83 (3) () 73.5'0 () eght8 are n grams nd lengths are:tn mllmeters. hwhen N 2 no statstca test s performed. Lean dry weght: see texte. -. * P<0.05 ** P<O.Ol '< 'j. U :7N ex...?.. -ll: ' C'

63 . :'- / o ===- [ Table 5. Comparson of ndces o lpd reserves (body weght/body length) of male and female adult greater scaup collected drng sprng 980 -': Early sptlng Late sprng Hale Female Male Female X ± SE (N) X ± SE (N) ± SE (N) X ± SE (N) Body weght/body length 2.25l±O.04 (7) N.T..934 () 2.46±O.05 (6) N.S. Z.50l±O.06 (3) N T ND tes t N.S. Not sgnfcant (O.05). 4 ' VI N I _._.. _ :

64 .--. l t_ r--- '-..--'!' - ' j l ' :: 'j Table'6. 00 a Comparson of body parameters of early and late sprng mgrant lesser scaup collected at Lake St. Lous Quebec 980 Male Femae Adult Juvenle Adut 3uvenle Parame ter ± SE (N) ± SE (N) ± SE (N) ± SE (N) Body weght Eary Late Breast muscle weght Early _Late (3) * 47.88±8.90 (8) 68.78± 0.98 (3) * 72.ll.5 (8) (5) * 802.4S±2.93 (8)' 64.57±.03 (4) 68.87±.40 (8) * 769.3±43.26 (3) * ±27.26 (3) 62.59± 4.57 (2) 72.56± 3.96 (3) ; (l) () Leg weght Early Late 3.94± 0.55'(3) 3.84± 0.4 (6) 3.00± 0.67 (5) 3.0± 0.59 (7) 28.73±.27 (3) 3O.45± 0.58 (3) () Gzza'rd weght Early La te 28.26±.06 (3) 29.6l±.20 (8) 26.70±.89 (5) 3O (8) JO.02± 2.2 (3) 26.46±.39 (3) () l ;. Smalt ntestne length Early Late (3) ±26.70 (8) (5) ±S5.3 (8) tl3.78 (3) 8JO.0 t75.4 (3) () Contnued Ù' W ----_

65 l l j l J -- Table 6 (Contnued) -... t '<'..._.....;..! ! ).lojii!fl L '... Parame ter Adult x ± SE (N) Male Juvenle ± SE CN) Adult x ± SE (N) Female Juvenle ± SE (N) ' Sma ntestne weght Early La te 6.78: 0.88 (3) ej '** 20.56± 0.63.(8) 4.98±. 72 (5) 8.40±.44 (8) 7.76± 0.8 (3) 24.9:t.65 (3) ' () Large ntestne ength Early 75.8 ±.70 (3) 76.2 :f 2.7 (5) 72.7 ± 4.98 (3) I:.ate 78.9 ±.0 (8) 80.9 ± 3.0 () 76.3 ± 3.8 (3).82.0 () -. Large ntestne weght Early Late.0± 0.07 (3) **.39± O06 (8).09± 0.0 (5).28± 0.7 (8).24± 0.7 (3)'.52:t 0..0 (3). 70 () Combned ceca length Eary Late -!'; ± 7.93 (3) 265.3±6.9 (8)' ±5.0S (5) t8.36 ( ±26.63 (3) ±5.68 (3) () Combned ceca weght EarlY Late.90± 0.05 (3).00± 0.05 (8) 0.88:!: 0.07 (5) l.02± 0.06 (8) 0:97± 0.7 (3) l.09:!: 0. (3).28 () COntnued Ut - t ;_.- ':' r

66 - r Il... - _ J.. r---; :ëj l TI J - }-... Table 6 (Contnued) ( Parame ter Male' Adult Juvenle Adult X ± SE (N) X ± SE (N) X ± SE.(N) Female Juvenle X ± SE (N). Skn weght Early Late 65.47± 7.2 (3) * ± (8)- 46.3± 3.9 (5) 76.99±.304 (8) 7. 34±2.06 (3} ±32.23 (3) () Abdomnal fat weght.r Eary Late. 7.92±.3 t!3).' < 3.79t.80 (l8?; 5.9±. (5). 22±.92 (8) 8.6:t 3.34 (3) 7.40± 5.4 (3) 0.06 () ;' Intstna 'Early Late fat weght.: 4.30± 0.42 (3) * 9.46±.5 (7) ' 3.32± 0.80 (5) 7.09±. 40 (8) 3: 78±.0 (3) 2.32:t 4.9 (3) 7.99 ().' Total fat weght Early.. Late (3)* 65.83±4.04 (6) ' ±3.ll (5).. '3. 3±l7.45 (8) :t (3) 95.85±40.0 (3) ' () Contnued 'J-r'... 'J'... :; VI J... z. _:--_... '....._... _ r_

67 :;:r'. r... o e.':. ':. ;.::;' :'.: ; ''. : C l'.. -:.. lk -. Table 6 (Contnued) Parala&ter Proten weght ' r Early La te Adult :!: SE on 62.09:!: 2.79 (3) 67.42t 2.65 (6) Halé' - Juvettlle x :!: SE (N) 49.56:!: 2.86' (5) 62.62± 4.0 (8) Adult :!: SE (N) ls.09:!: 4.76 (3) 66.l2± 4.25 (3) Female le _Juvenle x :!: SE (N) 50.6 () L.. l ' ' - '. r'<! ' & Fat-free weght Early Late / ± 8.78 (Il) 58.l7:!: 8.62 (l6) ±0.43 (5) 57l.49:!:.69 (8) ±5.64 (3) 584.7lO.52 (3) () u;:. '.. Weghts are n grama and lengths are n mllmeters. Lea dry weght: see texte *P<O.Os **P<O.Ol -- (.. l l. C? >..' f' VI ;

68 _ = 0 ' r-' -'. --- t '--. '_. '... r-'. (. ( -' Table 7. Comparson of ndces of lpd reserves (body weght/body length) of male and female adult esser scaup coected durng sprng 980 Early sprng Late sprng ---- Male Female Male Female ± SE (N) X ± SE (N) x ± SE '(N)---- ± SE-(N) _._.. ody weght/body length. 873±O.03 (3) N.S..885'o ±O.04 (8)- N.S. 2.l96±O.07 (3)... N.S. Dot sgnfcant (P>O.05). '' - - f} o VI '-J -;: '- :':'f. -. '> III ;---.t

69 ... r-.. r-.. '- f r '''-' l Table 8. Comparson of body weght$ Cg} of early and late fal greater scaup colected and ked by huner8 on Lake St. Lous Quebec.. Adult!8. Adu t femae ;;' ± SE (N) ± SE (N) :!: SE}... ± SE (N) p Eary ±29.65 '(4) 96.32±24.24 (9) () 97.7±27. (0) ** ( Late 077;34±24.5l (29) ±55.38 (6) ±33.68 (5) 02s.00±s6.57 (4) Eary Juvenle male ; Juvenle '. 979 x ± SE (N) j' ± S_{N) ± SE (N) / If- -_._ _ I ±28.7 (5) 4:89±45.s4 (9) 80.78±27.47 (6) Late 99.42±24.92 (]P) ±27.53 (8) ±23.46 (2) ( en N < 2 no statsteal st 8 performed. *P<0.05 **P<O.Ol # {. ** I.n co _... _......: 4a..' lau 'zte bd _ Il ----

70 f' (-- ' '-- '- '-- Table 9. Comparson of body wghts (g) of eary and ate fall mgrant essr scaup' coected and ked by hunters on Lake St. Lous. Quebec Adut male Adut femae ± SE (N) ± SE (N) ' :!: SE (N) at SE (N) a --._ Eary ±23.7 (4) * 88.25±30.7 (4). Late ±33.38 (7) ±9.22 (3) () ± 7.22 (4) :!:72.25 (3) ±47.50 (2) Juvenle male ± SE (N) ± SE (N) Eary ±9.4 (3) 66L67±38.44 (3) * La te 72.5±5.35 (7) * ± (8) Juvenle femae ± SE (N) ± SE (N) 73.64±8.62 (7) ±24.0 (3) * 73.63±5.4 (4) ±23.6 (9) 4 en N < 2 no statstcal-test a performed. o - *P<O :--- t4a.. 'ef'nt rat)8# (') :-' J

71 ---_._._-_._ _ :.: - ] ;;.... ( --' '--- r-- '- Table 0. Total molt scores of greater and esser scaup durng early and ate sprng980 Greater scaup Adult male J Juvenle male Adult female. Juvenle female Early Late Early Late Early Late Early La te (n=) _(l==6l..2) (n=4) (nl) (n-3) Cn;l) (n-l) Mean score 0.7 N.S N.S a a 8.00! ï Co Mnmum score O.O MaxDllm score '9.50 ft <;t. J Lesser scaup Adult male Juvenle male Adult female Juvenle female Mean score Barly (n=3) )Late (n=l8) 0.04 NS Early (n-s) 'Late Cn-8) 0.7 N.S Eary La te Eary (n-3) (n-3) (n-o) 7.7 N.S Late (n-l) 6.20 Mnmum sçore Maxmum score {) ' Sample sze too smal for statstcal test. N.S. No sgnfcant dfference between scores. r 0 o _re t... 7!.= PI!f! -.te rp '( r t.'_._.. -_... '_--'

72 0 '-'./ (.r--. r ---' -lf - Table. Malt scores of greater scaup by body regon durng eary and ate sprng 980 Early (n''7) Adut male La te (n-6) Juvenle male Early (n-2) Late (n-4) Adult femae Eary (n'l) Late (n-3) Juvenle female Early (n-i) - Late (n-) Sdes and flanks Mean MnllUDl - HaxlUDl 0.03 ' OOO l -- Upper breast and upper back Mean MnllUJll Maxmum ' J Lover b:east and bey Mean 0.00 Mnmum 0.00 Maxmum Md-back and rump Mean 0.00 Mnmum 0.00 Maxmum l Q... ; !

73 s m en..

74 '- t /' '- ISLAND OF ILE PERRT. #*-' ' --- ;-... -' : '.fii '... Il --Q '... / -... _ ' :- # '.' # ' l' I -' -...' ( #. #JJ--'.... '..:.... ' f -: 73 50' N S SPRtNe OBSERVATION POINT + F FALL OISERVATION POINT --.. '._) WEED BE D law Fgure. Map of Lake St. Lous Quebec showng observaton ponts from whch behavoural data were collected.!l'flunt r# fjî;r.-trl'.. '';7<'-J' -' )..... t.. )_.. _ _ 'UO _

75 _ '-- - : f) '--' ( '-' (/) o Cl L o f) a: I.&J CD 2 :) z '/.. ;0'- r'.' !5 29 MARCH APRIL 3 7 MAY Il 0- c.. '!. Fgure 2. Combned numbers of greater and lesser scaup on Lake St. Lous durng sprng 980. : r :----- 'N'<l!'l;I t -----:.::-;

76 f'... _. (r-.i -' f ='] -! ;< -() (J. :;:) 0 I.L () 0: lij.cd :2 5 ::) Z Fgure ' _... /.. -!t _. ' ' 7 ' I OCTOBER / / / / / _. - / /. ; / / / / NOVEMBER o'-{ lo O. 2. JO DECEM8ER Combned numbers of greater and esser scaup observed n mornlng flghts fr9jll Lake St. Lous to Lake of Two Mountans durng fau 979 and VI &' --:: tvb'tf -' UI'.J t-

77 ' t-: '-- ''--'.... G en.!! o -c 4).U '- 00 IID_=!=:::-! _ : : :.--: r =------=-----_-: en o E -c 4) u '- 3. IIIIIIIlllJlJ LllllllL..&! HJ IllllHH _-_-_-_-_-_-_-_-_':._- A -_-_- :..-_= --=-----= ;---= =-_--: Tme Tlme Feed ITl Rest f:::::) Preen a.a... t=â.swm [J]J] Fly Fgure 4. Daly pattern of frequences of actvtes of greater scaup n early sprng _ ' ''

78 r-- '--./ f ' ' -: :e_ 'OOIl!!I!!L!!-ll@=====;-= 80 f==j:= ==-;== r...-_- -_ ==== ==== === II) Q) 0 60 ::!: -c Q) 0... Q) Q.. ln.!! 0 E f -c: Q) e.. t... -/''''''' '.:..'...'.'.'..'.: ' Il Q) Q ; lme lme Feed lllti Rest Imm... Preen Ê== Swm [ID Fly Fgure 5 Daly pattern of frequences of actvtes pf greater scaup 'n late sprng '< -'ç

79 '...--= r ' III CI) '0 :E -c: cu (.)... tf } t Il WllUl JJUWlI -:..._-= ;9' IIIIIIII( _-_- -_-_= - ==-_-:...=_..; 00 III IIl :.IuIjJ III Il ut_-_-.;.-=.c:::==-=::2====_====_=_= -_ = :--_------= _--::-----= ; _ _ /) Il) '0 E If 'E Il) e cf / Tme 700 } 0900 /300 Tme /700 Fgur Feed mm Rest r.:m Elll Preen E Swm 6. Daly pattern of frequences of actvtes of lesser scaup n early sprng» 980. ' [[] Fly (7 00 l ' ï. l ) _

80 ._--... <O :t' L -. ' '0>.--- '---.- o 00 I I.. l?!j 80 en Q) ë 60 :!E -= = =-=-=-=-= :=-= =-:=-=-=-=-=-=-=-:: en.!!! c E Q) u _ _ IIIIIII ::.::.: o!:!.!.!:.::.:_-_-_-_-_-_-_-_-_-_ : = = J: u... () a. 40 -r:: Q) u... Q) a _ Jme ) f Feed o Rest - f:j:j:q preen ----_ Tme... '0 Swm rnn Fly ' ---- Fgure 7. -naly pattern of frequences of actvtes of lesser scaup n la te sprng 980. <; -.l; ' 0 ID D '.? ZfFRtSP n'sr -. % ( 5 MO '._- -: <) 0 x_v '<J dao. /. ) ' q. f I- l