j. RaptorRes.39(1):11-18
¸ 2005 The Raptor ResearchFoundation,Inc.
FIRST COMPLETE MIGRATION CYCLES FOR JUVENILE BALD
EAGLES (HALIAEETUS LEUCOCEPHALUS) FROM LABRADOR
DAWN K. LAING
AND DAVID
M.
Brad
Arian Science
and Conservation
Centre,McGill University,2i, ii i Laheshore
Road, Ste.Anne deBellevue,
Quebec,
H9X 3V9, Canada
TONY
E. CHUBBS
Department
of NationalDefence,
5 Wing Goose
Bay,Box 7002, StationA, HappyValley-Goose
Bay,
Labrador,Newfoundland
AOP 1SO,Canada
ABSTRACT.--We
documentedcompleteannual migratorycyclesfor five hatch-yearBald Eagles(Haliaeetus
leucocephalus)
from centralLabrador,Canada.We attachedbackpack-mounted
PlatformTransmitterTerminals (PTT) to track hatch-yeareagle movementsfrom their natal areas.The median departuredate
from natalareaswas26 October2002,with the earliestdepartureoccurringon 7 October2002and the
lateston 12 November2002.All eaglesmigratedindependentlyof siblingsand spenta mean of 62 d on
autumn migrationat a mean speedof 45 km/hr with a mean of five stopovers.
Eaglestravellednorth in
the springat an estimatedspeedof 27 km/hr over32 d, with a maximumof 11 stopovers.
One wintered
in the Gulf of St. Lawrence,while the remainingeaglesmigratedto the northeasternU.S.A. Eaglesspent
a mean of 76 d on their winteringgrounds,with a median date of departurefor springmigrationof 20
March 2003. Two of the eaglesreturned to Labrador during their first summerand showedsomefidelity
to their natal areas.We documentmigrationroutesand identify stopoverareas.
KEYWORDS: Bald Eagle,,Haliaeetusleucocephalus;migration;
juvenile,,satellitetelemetry;
stopov• dispersal;
Labrador.
PRIMEROS CICLOS MIGRATORlOS COMPLETOS PARA INDMDUOSJUVENILES
•UCOCEPHALUS
DE HALIAEETUS
DE LABRADOR
RESUMEN.--Eneste estudio documentamoslos ciclosmigratoriosanualescompletospara cinco individuosde la especieHaliaeetus
leucocephalus
durante su afio de eclositn en Labradorcentral,Canadfi.Para
seõuirlos movimientosde las figuilasdesdesu lugar de nacimiento,les acoplamosterminalestransmisorasde plataformapor medio de morrales.La mediana de la fecha de partida de lasfireasnatalesfue
el 26 de octubrede 2002. E1abandonomilstempranosucedi6el 7 de octubrey el milstardio el 12 de
noviembrede 2002. Todaslasiguilas migraronindependientementede sushermanosy permanecieron
en promedio 62 dias en migracitn de otofio a una velocidadmedia de 45 km/hr, realizandoun promedio de cinco paradasdurante la migracitn. Las avesviajaron hacia el norte en la primaveraa una
velocidadestimadade 27 km/hr a lo largo de 32 dias, con un m2ximo de 11 paradas.Una de ellas
past el invierno en el Golfo de St. Lawrence,mientrasque lasdemilsmigraronal norestede losEstados
Unidos.Las figuilaspasaronun promediode 76 dias en susfireasde invernada,y la medianade la
fecha de partida para la migracitn de primaverafue el 20 de marzo de 2003. Dos de los individuos
reõresarona Labrador en su primer verano y mostraron cierta fidelidad a sus fireas de nacimiento.
Tambitn documentamoslas rutas de migracitn y las •treasimportantesde escalamigratoria.
[Traduccitn del equipo editorial]
A southwardmigration of post-fiedgingBald Eagles (Haliaeetusleucocephalus)
from northern Canadian natal areas to southern wintering grounds
haslong been known (Gerrard et al. 1978). Banding and radiotaggingeagleshave producedlimited
• Email address:[email protected]
11
results (Gerrard et al. 1992). With the advance-
ment of satellite-telemetrytechnology,information
on the ecologyand life history of raptors has been
greatly expanded beyond what could possiblybe
gathered during decadesof conventionaltelemetry
and banding (Meyburg et al. 1995, Ueta et al. 2000,
Hake et al. 2001, Kjellen et al. 2001). Using both
12
LAING ET AL.
bandingdataand conventionaltelemetry,dispersal
behavior,movements,and survivalof juvenile Bald
Eagleshavebeen documentedfrom Florida (Wood
et al. 1998), Saskatchewan(Gerrard et al. 1978,
Harmata et al. 1985), Wyoming, Galifornia (Hunt
et al. 1992), Texas (Mabie et al. 1994), and Golorado (Harmata 2002). Little is known about eagle
activities beyond their first winter, limiting our
VOL. 39, NO. 1
from the nest to an adjacent area, where birds were processedand banded. Once captured, eagleswere fitted
with 95-g, battery-poweredPTT-100 transmitters(MicrowaveTelemetry Inc., Columbia, MD U.S.A.) affixed in a
backpackharnessfashionusingTeflon ribbon (BallyRibbon Mills, Bally,PA U.S.A.). Eachtransmitterwassetwith
a presetduty cycleto transmitto satellitemorefrequently
(8 hr on, 48 hr off) during possibleperiodsof migration,
mostfrequentlyduring October and March and lessfrequently during summer and winter months.All eagles
knoMedgepertainingtojuvenile stopoverhabitats, were banded with a U.S. Geological Surveyaluminiummigratoryflyways(McGlellandet al. 1994, 1996), rivet band on one tarsus and a colored-metal-alphanumeric-rivet band (Acraft Sign and Nameplate Co. Ltd.,
and sourcesof possiblemortality (Buehler et al.
1991). Furthermore, little information is available
regardingdistribution,nestingchronology,and migration timing and routeson the easternGanadian
populationof Bald Eaglesin Labrador.
Wetmoreand Gillespie(1976) conductedinitial
investigations
of BaldEaglesin Labrador,and since
1991, the Ganadian Department of National Defence (DND) has been monitoring nest sitesand
productivitythroughannual surveys(DND 1995).
Edmonton, Alberta, Canada) on the other.
We monitored eagle movementsusing the Argos Data
Collection services (ARGOS 2000). We determined nest-
ing sites,stopoverdetails,wintering areas,and migration
routesusing the location data receivedvia satellite.Prior
to processing,we put location data into a databaseusing
a GeographicInformation System(GIS), and movement
wasthen analyzedusingESRI© ArcView3.2 (ESRI,Redlands, CA U.S.A.) in combination with the Animal Move-
ment Extensions program (Hooge and Eichenlaub
1997). The Argos System divides data into different
classesbased on validation and number of messagesreTo date, there are some 30-40 known Bald Eagle ceived. Location classes(LC) are ranked by accuracy
nest sitesin Labrador (T. Ghubbs unpubl. data). (3>2>I>0>A>B>Z;
accurate to least accurate) by ArAs part of a larger study investigatingthe move- gos;however,we found that severallocationsper transments of raptors within and out of Labrador missionperiod were sufficient to document raptor move(Laing et al. 2002), we implemented a satellite-te- ments if reviewed individually. Location validity and
accuracywere further determinedby comparingconseclemetry program to track five hatch-yearBald Ea- utive locationsto previouslocationsresultingin a moveglesfrom August2002-August2003.
ment estimate.Usingthisscreeningmethodwewereable
to include more than one transmissionper reporting peSTUDY AREA AND METHODS
riod, independent of location classand quality index
Our studytook place within the Low Level Training Therefore, based on existing literature demonstrating
Area (LLTA) for fighter aircraft, coveringan area of ca. meanjuvenile eagle ratesof movement(Buehler 2000),
130000 km9 spanningthe Labrador-Qutbecnortheast- we accepted a location if the movement estimatereportern border. We searchedfor occupied raptor nestsin the ed for a bird was0 km/d, but rejected it if the movement
vicinityof the Smallwood
Reservoir,ca. 6700km2 of cen- estimatewas greater than 500 km/d. We then compiled
a databasecomparingthe number of locationsusedfor
tral Labrador. This area consistsof water bodies, prominent rocky islands,isolatederratics,and rock outcrops. analysisand divided this number by location estimates
Surrounding the reservoir are shorelinesunder I m of received to determine a percentage of viable-satellite
water and that are littered with driftwood, while beyond transmissions (LC Z-transmissionswere removed and not
the waterline are standsof black spruce (Piceamariana). used in estimates).
As the transmitterswere programmed following a preWetlands in this low subarctic ecoclimate are subject
to permafrost.This region has a mean annual tempera- determinedduty cycle (i.e., September-October8 hr on
ture of -3øC, a mean summertemperatureof -9øC, and and 48 hr off, and November-December alternated bea mean winter temperatureof -16øC (Meades1990). De- tween 8 hr on and 72 hr off and 8 hr on and 168 hr off),
pending on latitude, the mean annual precipitation exact datesof departure from nestingsitesand arrivals
rangesfrom 700-1000 mm (McManusand Wood 1991). at wintering groundsare unknown.To estimatedatesof
Bald Eaglestypicallynestalong riversand large reservoirs arrival we considered that a raptor migrating to an area
had arrivedby the firstdate a locationwasobtainedfrom
in dominant white birch (Betulapapyrifera),balsam fir
(Abiesbalsamea),
larch (Larix laricina),poplar (Populusbal- that area. On departure its locationwasconsideredto be
samifera),and blackspruceat a height of 15-30 m (Bider the location estimate received from within the area. An
and Bird 1983). We have observed eagle nests in all of area was considered to be a stopoversite if we received
location estimatesfrom an area for at least24 hr (Kjellen
these tree speciesin Labrador.
Rock pinnaclesand treesare usedby nestingBald Ea- et al. 2001) and the bird demonstrated concentrated loglesin Labrador.However,due to the inaccessibility
and calized movement.
Distances
travelled
between
summer
and winter
remotenessof tree nests, hatch-year eagles (8-10 wk)
were captured from rock nestssituatedin lakes and res- groundswere calculatedby adding the linear distances
ervoirs. Nestswere accessedusing a ladder or by moun- from the departure point to the arrival location,includtaineering techniques,and birdswere removedby hand ing distancesto and from stopoverlocations.We calcu-
MARCH 2005
EAGLE MIGRATION
lated radial distancesfrom capture sitesusinga 95% Kernel home-range estimator, with the Animal Movement
Extensionsprogram (Hooge and Eichenlaub 1997),
which determined an estimate of the area used by the
eagle.
RESULTS
During the 2002 summerfield season(15-30 August) fivejuvenile eagleswere captured and fitted
with PTTs. We recorded
6472 locations between 15
August2002-30 August2003. Of these,75% were
usedin analysis.A mean of 966 locationsper eagle
was collected with only the most-likelylocations
plotted using GIS (0% Z, 20% B, 19% A, 32% 0,
22% 1, 5% 2, and 2% 3). Of thosecaptured,eagles
37414and 37413 and eagles37412and 37415were
siblings, respectively, and 37411 was captured
alone.
Movements before Fall Migration. Eagles remained
within
their
natal area for a mean
of 74 d
following transmitter attachment, with departures
asearlyas7 October 2002 and aslate as12 November 2002, and a median departure date of 26 October 2002. Each bird exhibited exploratoryflight
patterns,and useda mean range of 165 km9 (97252 km2) around original capturesites.
Fall Migration. During autumn migration, the
eagles averaged five stopoversprior to reaching
their wintering destinations,with staysranging between 24 hr and 25 d. The eaglestook between595 d to reach their wintering areas,with straightline distancesbetween natal areas and wintering
areas ranging from 510-930 km (Fig. 2).
Eagle37414 (Fig. 1) travelledthe shortestlinear
route south, probably departing its nest site on 13
November 2002. Generally, the relatively infrequent location estimatesfrom Argos were insufficient for tracking the birds' routes, and therefore,
there were likely deviations from a straight line.
However, during fall (and spring) migrations we
receivedlocation estimatesas often as once every
2 d, suggestingthat our estimatesrepresented fair
delineations
of movement.
The
next
transmission
date for eagle 37414, 18 November 2002, was located along the northern coastof the Gulf of St.
FROM LABRADOR
13
wintered in Virginia and WestVirginia, respectively. Eagle 37412 had four stopoversbefore reaching
its wintering grounds of Albany, NY, on 1 December 2002, travelling more than 2444 km after leaving its natal area. Eagle 37415 had six stopovers
prior to reaching its wintering grounds of Orange
County,VA, on 5 February2003, ca. 1370 km from
its natal
area.
Eagles37411 and 37413 (Fig. 1) left the Gulf of
St. Lawrence
and
moved
toward
the
U.S.A.
east
coast, stopping along the borders of VT and NH.
Eagle 37411 made 11 stopoversand travelled ca.
1420 km before reaching its wintering grounds
along the Hudson River betweenUlster and Dutchesscounties,NY. Eagle 37413 travelledca. 1640 km
before settling in Hartford County, CT, with half
the number of stopovers.
Movements before Spring Migration. The mean
overwinteringperiod was76 d, (44-124 d), except
for 37414 which remained on wintering grounds.
Spring Migration. We defined spring migration
as the period of time in which the birds departed
from wintering grounds and arrived at summering
grounds. Once on the summering grounds, the eaglesdid exhibit exploratoryand nomadicflight behaviour.Eagle 37414 did not migrate in the spring;
however, it moved within the same 252 km 9 area
for the whole summer and did not venture away
from
the Gulf
of St. Lawrence.
Departure dates for the four remaining eagles
were between
11-27
March
2003.
The
birds had
two to six stopoversprior to reaching the Gulf of
St. Lawrence. Three of the four eagles (Fig. 2)
used similar routes as taken during fall migration
to travel north, with the exceptionof 37415 which
travelled more easterly.Eagle 37415 did not stop
at Lake Ontario when travelling north in the
spring and meandered west of its original autumn
route (Fig. 2). All of the eagleswere tracked to the
Gulf of St. Lawrence;two eaglescontinued further
north to the Quebec and Labrador border for the
summer.
All four
birds arrived
at the north
shore
wintered, and remained, in the gulf area through
the spring migration period. The remaining four
eaglesstopped along the north shore in Qutbec,
continued southwest, and avoided crossing the
of GaspC Quebec, between 11-30 April 2003, averaging 32 d on migration.
Eagle 37413 left its wintering ground first on 10
March 2003, travelling northeasterlyfor 1100 km
with three stopoversand arriving at the Gulf of St.
Lawrence on 21 April 2003. Comparatively,eagles
37412 and 37415 left their wintering grounds at
Gulf
similar
Lawrence, 472 km from its natal area. This bird
of St. Lawrence.
times
and travelled
1955
km and
1600
km
Eagles 37412 and 37415 (Fig. 1) took similar to arrive at the Gulf of St. Lawrence on 21 and 26
routes southwest,stopped at Lake Ontario, and April 2003, respectively.Eagle 37411 left its winter-
14
LAING ET AL.
VOL. 39, NO. 1
Hudsd13
•
•ay•
•
•B••.
' ' •:15Aug02•
,••
•
/
•
•15Aug02• •
•. to
•i' • •,v •,• Ocean
•
•, Ocean
k•"• ••ec
0•,
137411
•, •
'.,,• 15Aug
02
to
•
,,
•
PQ•
•
• •a•
••
1374•21
Nesting•ea
ß Autumn
Locations
•.••
ON
•
,u•umn
Migration
Rou•e
NH
'
MA
0
700
I
Atlantic
,
km
Oean
1374•3
Hudso•
•15
Aug
02
'ON
Oean Oean
•
1374141
•
Figurel.
C •
•
•
Fe•
•
1374•1
Fall migratoryroutesofjuvenileBaldEaglesfrom their natalsitesin Labradorto theirwinteringgrounds
as tracked by satellite in 2002.
MARCH 2005
EAGLE MIGRATION FROM LABRADOR
15
Figure 2. Springmigratoryroutesof juvenile Bald Eaglesfrom their wintering sitesto their summeringgroundsas
tracked by satellitein 2003.
16
LAING ET ^L.
ing grounds the latest (26 March 2003), and trav-
VOL. 39, NO. 1
elled 790 km to its summeringgroundswith three
stopoversto arrive at the Gulf of St. Lawrenceon
linked to weather or foraging opportunities.Becauseall five eagletswere captured at the samelatitude and longitude, theywere exposedto many of
9 April 2003.
the same weather conditions. Therefore, weather
Eagle 37413 divided its summer activitiesbetween
the Gulf of St. Lawrence
and New York State.
Eagle 37415 waslocatedon the Qutbec and New
Brunswick borders on 1 May 2003 (Fig. 2) and
moved south again to New York on 15 May 2003.
It then
returned
to the Gulf
of St. Lawrence
on 8
June 2003. On 12 August 2003, this bird began
moving south to New York.
Eagles37411 and 37412 left the Gulf of St. Lawrence between3-6 May 2003 (Fig. 2). Eagle37411
characteristics
such as the first snow fall or frost
event could have contributed by triggering the initiation of migration of individuals.Conversely,
Harmata et al. (1999) statedthatjuvenilesmay exhibit
movement that is individuallycharacteristicof the
juvenile and exclusiveof foragingopportunities.
Montana juvenile eagles (McClelland et al.
1996) departed their natal territories between 22
August-5 October (median = 9 September,N =
5), Saskatchewan
juvenilesleft at the beginningof
flew 400 km to the CaniapiscauReservoir (Qut- October (Gerrard et al. 1978), and a population
bec) and later spenttime at the OssokmanuanRes- in southern California departed between 19 Julyervoir (Labrador). Eagle 37412 travelled 617 km 22 August (Hunt et al. 1992). More northern studmovement
from northern
north and spent its summer at the SmallwoodRes- ies have documented
ervoir.
Saskatchewan as late as 3 November (Harmata et
All eagles moved sporadicallyduring the summer period, with mostlocation estimatesindicating
al. 1999). Generally, Labrador eagles migrated
activities
on the north
shore of the Gulf of St. Lawr-
south late in the season (median = 26 October).
While the four eagletstravelled independently
of one another, some went in a similar direction
ence.
(i.e., southwestof natal areas), moving between
lakes and rivers and exploiting aquatic environThe departure of juvenile Bald Eaglesfrom their ments.They made severalstopoversalong the way,
natal nest sitesin Labradorhasbecomemore pre- most near larger water-bodiessuch as the Gulf of
dictable with the application of satellite technolo- St. Lawrence,Lake Ontario, and Lake Champlain.
gy. Juvenile Bald Eagles from Labrador migrated Gerrard et al. (1978) believedthat juveniles folsouth or southwest,consistentwith previousjuve- lowed rivers and were found near lakes as these
nile Bald Eagle migration reports (Gerrard et al. areas represented favourable habitat. Montana ea1978, 1992, Hunt et al. 1992, McClelland et al. gles also made stops, sometimesfor weeks at a
1994, 1996, Harmata et al. 1999, Harmata 2002).
time, enroute to wintering areas (McClelland et al.
Autumn
movement
was south toward the Gulf of
1994, 1996). These stopsprovidedan opportunity
St. Lawrence prior to dispersingen route to win- for eaglets to replenish nutrients lost during miDISCUSSION
tering areas.
We know from previousstudiesthat juvenile migration may be initiated by changesin foragingopportunities (Hodgeset al. 1987, Hunt et al. 1992,
gration. Restani et al. (2000) elaborated on the
functional responseon stopoversmade by migrant
Bald Eaglesthrough Montana. They found that the
eaglesstopped while passingthrough a corridor,
McClelland
80-130
et al. 1994, Restani et al. 2000, Hoff-
man and Smith 2003), with birdsdepartingan area
if prey is not readily available.Hunt et al. (1992)
suggestedthat eagletsfirst leave on exploratory or
foragingflightsand return to nestsitesthroughout
the day for possiblefood provisioning by adults.
What specific cue triggers migration in Labrador
eaglesis not known. In the weeksfollowingfledging, all fivejuvenile eaglesremained in natal areas
and exhibited exploratory flights within a 40-km
radius of original nestareas,occasionallyreturning
km wide, around the Hauser Reservoir,
GlacierNational Park. The eaglesdetectedconspecificsforaging from 40-65 km awayand then travelled
into the area to feed. The birds used this res-
ervoir as a stopover during both northward and
southwardmigrations. We documented the use of
the
St. Lawrence
River
and
the
Gulf
of St. Law-
rence as both spring and autumn migration stopoversfor Labrador juvenile eagles.The mean travelling distance from wintering to summering
grounds was 350 km less than the distancestravto the nest.
elled from natal areas to winter grounds.We susAutumn departure may have been partially pect that Labrador eaglesgained experiencedur-
MARCH 2005
EAGLE MIGRATION FROM LABRADOR
ing their autumn migration, and that their flight
routes and strategieswere more defined and less
nomadic in the spring. Eagles may improve their
senseof direction on northern flights through visual cues,mentally cataloguedstopovers(Hake et
al. 2001), and increasedflight experience.
Spring departure of juveniles occurred between
11-27 March 2003, and the four migrating eagles
used the Gulf of St. Lawrence fall stopover (median = 21 April 2003) prior to arriving at summering grounds (between 3-6 May 2003). Nonbreeding birds are more apt to spend time away
from optimal nesting areas and focus on fayourable foragingsitesrather than establishinga breeding territory (Jenkins et al. 1999). Basedon the
survivalof our five PTT-tagged birds, the Gulf of
St. Lawrence was a suitable stopoversite, and provided adequateforaging habitat for travellingBald
Eagles.
ACKNOWLEDGMENTS
This project would not have been possiblewithout the
funding support of the GooseBay Office, Department of
National Defence, Canada.We alsoacknowledgethe support of McGill University,Gary Humphries, and the Department of Tourism, Culture and Recreation (Endangered Speciesand BiodiversitySection). We thank M.
Solenskyfor demonstrating proper transmitter attachment techniquesand for assistingin the field. We thank
L. Elson, G. Goodyear,and P. Trimper for their help in
the field. We are grateful to Capt. (N) K.D. Laing for his
editorial assistance. We also thank M. Fuller, M. Restani,
and M. Goldstein for comments that greatly improved
the manuscript.
LITERATURE
CITED
17
fence Headquarters Project Office, Ottawa, Ontario,
Canada.
GEPmARD,
J.M., D.W.A. WHITFIELD,P. GERRAmg,
P.N. GER-
RAm),aND WJ. MAHER.1978. Migratory movements
and plumage of subadult SaskatchewanBald Eagles
Can. Field-Nat. 92:375-382.
, P.N. GERRARD,G.R. BORTOLOTTI, AND E.Z. DZUS.
1992. A 24-yearstudyof Bald Eagleson BesnardLake,
Saskatchewan.
J. RaptorRes.26:159-166.
HAKE, M., N. KJELLEN,AND T. ALERSTAM.2001. Satellite
tracking of SwedishOspreysPandionhaliaetur.autumn
migration routesand orientation.J. Arian Biol.32:4756.
HA•MAT^, A.R. 2002. Vernal migration of Bald Eagles
from a southern Colorado wintering area. J. Raptor
Res. 36: 256-264.
--,
J.E. TOEPFER,ANDJ.M. GEmmrd. 1985. Fall m•gration of Bald Eagles produced in northern Saskatchewan.BlueJay43:232-237.
--,
F. MONTOPOLI, B. OAKLEAF,P. HARMATA, AND M.
RESTAN1.
1999. Movementsand survivalof Bald Eagles
banded in the greater Yellowstoneecosystem.
J. Wildl
Manag. 63:781-793.
HOBOES,
J.I., E.L. BOEICER,
ANDAJ. HANSEN.1987. Movements of radiotagged Bald Eagles, Haliaeetusleucocephalus, in and from southeasternAlaska. Can. FieldNat.
101:136-140.
HOFFMAN,S.W. ANDJ.P. SMITH. 2003. Population trends
of migratory raptorsin westernNorth America, 19772001. Condor 105:397-419.
HOOGE, P.N. AND B. E1CHENLAUB.1997. Animal move-
ment extension to ArcView,Ver. 1.1. AlaskaBiological
Science Center, U.S. Geological Survey,Anchorage,
AK U.S.A.
HUNT, W.G., R.E. J^CKMAN,
J.M. JENKINS,C.G. THEL^NDER,ANDR.N. LEHMAn.1992. Northward post-fledging
migration of California Bald Eagles.J. RaptorRes.26.
19-23.
ARGOS.2000. User's manual. Service Argos, Inc., Largo,
JENKINS,
J., R. J^CKMAN,
ANDW. HUNT. 1999. Survivaland
MD U.S.A.
movements of Bald Eagles fledged in northern CahBIDER,J.R. aND D.M. BIRD.1983. Distribution and densifornia. J. RaptorRes.33:81-86.
ties of Osprey populationsin the Great Whale Region KJELLEN,
N., M. H•d•, ANDI. ALEP,
ST•V•.2001. Timing and
of Qufbec. Pages 223-230 in D.M. Bird, N.R. Seyspeed of migration in male, female, and juvenile Osmour, andJ.M. Gerrard [EDS.], Biologyand managepreysPandionhaliaetusbetweenSwedenand Africa as
ment of Bald Eaglesand Ospreys.Harpell Press,Ste.
revealed by field observations, radar and satellite
Anne de Bellevue, Qufbec, Canada.
tracking.J. Avian Biol.32:57-67.
BUEHLER,
D.A. 2000. Bald Eagle (Haliaeetusleucocephalus). LAING, D.K., D. BIRD, T. CHUBBS, AND G. HUMPHRIES
In A. Poole and E Gill [EDs.], The birds of North
2002. Migration routes, timing, and nest site fidelity
2Mnerica,No. 506. American Ornithologists' Union,
of Osprey (Pandionhaliaetus)and Bald Eagles (HalWashington,DC U.S.A.
iaeetusleucocephalus)
as they relate to military aircraft
--,
J.D. FRASER,
J.K.D. SEEG^R,AND G.D. THERRUS.
activity in Labrador. Pages 82-92 in B. MacKinnon
and K. Russell [EDS.], BirdStrike 2002 conference
1991. Survivalrates and population dynamicsof Bald
Eagles on ChesapeakeBay.J. Wildl. Manag. 55:608proceedings,August 19-21 2002. Transport Canada,
613.
DEPARTMENT
OF NATIONAL
DEFENCE.
1995.
An
environ-
mental impact statement on military flying activities
in Labrador and Qu6bec. Goose Bay National De-
Toronto, Ontario, Canada.
MArnE, D.W., M.T. MERENDING, AND D.H. REID. 1994. Dis-
persal of Bald Eagles fledged in Texas.J. RaptorRes
28:213-219.
18
Laisg ET AL.
VOL. 39, No. 1
MCCLELLAND,
B.R., L.S. YOUNG,P.T. MCCLELLAND,
J.G. RESTANI, M., A. HARMATA, AND E. MADDEN. 2000. NumerCmiNSHAW,H.L. ALLEN,AND D.S. SHEA.1994. Migraical and functional responsesof migrant Bald Eagles
tion ecologyof Bald Eaglesfrom autumn concentraexploiting a seasonallyconcentratedfood source.Contion in Glacier National Park, Montana. Wildl.Monogz
dor 102:561-568.
125:1-61.
UETA, M., E SATO, H. NAKAGAWA, AND N. MITA. 2000
, P.T. MCCLELLAND, R.E. YATES, E.L. CATON, AND
M.E. MCFADZEN.
1996. Fledging and migration of juvenile Bald Eaglesfrom Glacier National Park, Montana.J. RaptorRes.30:70-89.
MCMANUS, G.E. AND C.H. WooD.
1991. Atlas of New-
foundland and Labrador.Breakwater,St.John's,Newfoundland, Canada.
MEADES,sJ, 1990. Natural regions of Newfoundland and
Labrador. Protected Areas Association, St. John's,
Newfoundland,
Canada.
Migration routes and difference of migration schedule between adult and young Steller'sSea EaglesHaliaeetuspelagicus.
Ibis 142:35-39.
WETMORE,
S.P.ANDD. GILLESPIE.
1976. Ospreyand Bald
Eagle populationsin Labrador and northeasternQutbec, 1969-73. Can. Field-Nat. 90:330-337.
COLLOPY, AND c.n. SEKERAK.1998.
WOOD, P.B., n.w.
Postfledgingnest-dependenceperiod for Bald Eagles
in Florida. J. Wildl. Manag. 62:333-339.
MEYBURG,B.-U., J. MENDELSOUN,
D. ELLIS,D. SMITH, C.
MEYBURG,AND A. KEMP. 1995. Year-round movements
of Wahlberg'sEagle Aquila wahlbergi
trackedby satel- Received 23 March 2004; accepted 16 November 2004
lite.
Ostrich 66:135-140.
Associate
Editor:
Michael
I. Goldstein