The Road to the Place of the Eagles

The Road to the Place of the Eagles
Feature Article by Peter Sherrington
I
t is late afternoon on December 9, 2007,
and I have finally called a halt to the
second season-long autumn raptor
count at our Piitaistakis-South Livingstone
site near the Crowsnest Pass in
southwestern Alberta. We started on August
25 and have spent 100 days in the field. We
have survived temperatures in the minus
twenties and wind gusts to 150 km/h on the
1900 m high ridge. And we have tallied
almost 8300 southbound migrating raptors
of 17 species. Included in the total were 700
Bald Eagles, 1219 Sharp-shinned Hawks,
166 Northern Goshawks, 188 Red-tailed
Hawks, 35 Peregrine Falcons, and a truly
astounding 5445 Golden Eagles. Finally, I
am convinced that we have found our longsought El Dorado!
It has long been known that Golden
Eagles migrate through the western
cordillera. In 1970, Dick Dekker reported
Golden Eagle movement in the Alberta
foothills near the Bow Valley. In 1974,
well-known falconer and artist Frank
Beebe noted that “a major flight of Golden
Eagles moves along the eastern front of the
Rocky Mountains from central Alberta to
Mexico in the fall, and back along the same
route in the spring.” He speculated that
many thousands of eagles were involved,
but provided no supporting details. In the
m i d - 1 9 8 0 s , Wa y n e S m i t h b e g a n
conducting fall reconnaissance counts at
Windy Point in the Sheep River valley
southwest of Calgary, and recorded steady
movements of Golden Eagles following the
mountain front.
Nearly all previous records of
migrating eagles had been from the
foothills area, and it was generally assumed
that migration was concentrated there. Rare
sightings of concentrations of Golden
4
BIRDWATCH CANADA
Photo: Ron Ridout
Eagle watchers at Mt. Lorette Photo: Cliff Hansen
Eagles migrating in the mountains were
generally considered anomalous.
Particularly noteworthy was the almost
complete lack of migration records from
Banff and Jasper National Parks.
Sixteen years ago, Des Allen and I
stumbled on an eagle ‘highway’ following
the Front Ranges of the Alberta Rocky
Mountains while conducting a general bird
survey in the Mount Lorette area of the
Kananaskis Valley west of Calgary. It all
started on March 20, 1992 with a single
soaring Golden Eagle that I saw at 11:30.
By the end of the day, we had counted over
100 of the birds gliding high from the Fisher
Range across the valley to Mount Lorette
where they soared before disappearing,
following the ridges to the northwest. Over
the next seven days, our final tally of 389
birds convinced me that the migration event
merited follow-up investigation.
In fall 1992, I returned to the Mount
Lorette site to see if the route was also used
for southward migration. With a growing
number of keen volunteers, including Jack
Steeves and Bill Wilson, I spent 33 days at a
site close to the base of Mount Lorette. We
recorded the passage of 2044 Golden
Eagles, including a single-day count of 476
on October 6. I was now becoming
seriously intrigued. I decided to do a full
count in spring 1993 at a valley bottom site
in the Hay Meadow beside the Kananaskis
River, immediately east of the Nakiska ski
hill. After 48 days, we had counted 4140
Golden Eagles – 849 of which were counted
on March 25 alone, giving me the first real
intimation of the massive numbers of birds
that might be involved in this migration.
Volunteers started watching at other
sites. We quickly traced a fairly linear route
moving through the Front Ranges of Banff
and Jasper National Parks to the north and
along the Fisher, Misty, and Livingstone
Ranges to the south. By this time it had
become obvious that we were dealing with a
true migration involving both adult and
immature birds. With most of the adult birds
moving in March, we suspected their final
destination was far to the north in Alaska
and the Yukon.
The first full fall count in 1993 yielded
5605 migrant raptors of 16 species,
including 4599 Golden Eagles in 75 days. In
70 days the following spring, we counted
4695 migrants, of which 4213 were Golden
Eagles. During these count periods we
continued to explore other sites. In fall
1994, we decided to count both at Mount
Lorette and at a site near Barrier Lake, some
10 km to the north. This second site, which
could not be seen from the Lorette site,
tapped a stream of birds moving along the
mountain front and high foothills, possibly
connecting with Wayne Smith’s Windy
Point site. This count was organized by
Rodger Dunn. Over a period of 48 days,
they recorded 2195 Golden Eagles moving
parallel to and east of the 3836 birds counted
at Mount Lorette in 70 days of observation,
for a total of 6031 Golden Eagles. We now
wondered whether there was a place where
these two streams came together to produce
the greatest concentration of Golden
Eagles. If so, where was this El Dorado?
There is a general narrowing of the
Front Ranges to the south. Reconnaissance
counts were conducted by George
Halmazna at Highwood Pass and Plateau
Mountain (about 60 km and 100 km south
of Mount Lorette, respectively) and by Liz
Saunders at the Livingstone Gap (140 km
south of Mount Lorette). These counts
produced encouraging results.
In the meantime we continued counting
at Mount Lorette, spending increasingly
more time at the site. We found that Golden
Eagle movement extended from midFebruary to late May in the spring, and from
late August to early or mid-December in the
fall. During the height of migration in
March and October, birds could be seen
migrating from dawn to dusk on any given
day.
In 1997 we decided to conduct a full
count on Plateau Mountain, and spent 75
days watching from elevations up to 2500
m. We had excellent views of the birds here
(we assigned an age class to over 99% of
them), but at the end we had ‘only’ counted
3853 Golden Eagles – a number similar to
what we would have expected to have
counted at Mount Lorette. Although it was a
splendid place to view raptors, Plateau
Mountain was obviously not El Dorado.
Because of its remoteness and the logistical
difficulties of conducting a full-season
count there, we decided to return to Mount
Lorette. By 1997 we realized that to ensure
the continuation of this ever-expanding
project, we needed to become more
organized. Largely through the efforts of
SPRING 2008, NUMBER 43
FEATURE
ON THE WATCH
Photo: Ron Ridout
Rosemary Power, we founded and
incorporated the Rocky Mountain Eagle
Research Foundation as a charitable
organization.
George Halmazna and Doug and
Te r e s a D o l m e n c o n t i n u e d t o
independently explore for migration
routes in southernmost Alberta. In fall
1998, Doug and Teresa watched for the
first time at a site they called South
Livingstone. This 1900 m site at the
southern end of the Livingstone Range is
near the town of Frank in the Crowsnest
Pass. In just three days, they recorded
210 Golden Eagles.
That same fall, Harvey Kuszmaniuk
and I travelled to the Pine Pass area west
of Chetwynd in northeastern British
Columbia. After two weeks of rain and
snow, we eventually found Golden
Eagles moving south along the ridges of
the Front Ranges east of the pass.
Subsequent reconnaissance counts by
Sandra Kinsey and Laird Law, out of
Prince George, found that although the
movement there is steady and
predictable, the numbers are
consistently much less than those at
Mount Lorette. The movement at this
latitude is likely more diffuse, with the
birds using a number of mountain and
foothills ridges.
Explorations in the Tumbler Ridge
area slightly to the south suggest a
similar situation there. For a number of
years around this time we reconnoitered
various places on the western flanks of
the Rocky Mountains in the Columbia
Valley, BC, but generally with
disappointing results. Mount Lorette
continued to be our principal site in both
spring and fall.
Doug and Teresa continued their
pilot surveys at South Livingstone,
counting 1137 Golden Eagles in nine
days in fall 1999, and 1304 in just five
days in 2000. The year 2000 proved to be
the most spectacular count to date, with
October 6 yielding 436 Golden Eagles at
Mount Lorette, and Wayne Smith
counting 420 at Windy Point. The
following day, George saw 535 birds
pass Plateau Mountain, and on the 8th
Doug and Teresa saw an amazing 1071
Golden Eagles at South Livingstone,
with birds already in flight when they
arrived at the site. This still remains the
largest single-day Golden Eagle count
ever recorded. It looked as if this could
be El Dorado, but it would be a few more
years until we could confirm this.
We continued gathering valuable
data at Mount Lorette and conducting
reconnaissance counts elsewhere. On
October 15, 2004 we experienced
5
Peregrine Falcon/Faucon pèlerin Photo: Gord Court
another flood of Golden Eagles. In a period
of just six hours, 573 birds moved south –
much to the delight and amazement of a
group of Japanese eagle researchers who
were visiting the site for four days.
In 2006, thanks to generous support
from Enbridge and unstinting logistical
support from the Crowsnest Conservation
Society, we were able to conduct the first
full fall count at South Livingstone. We
started on August 27 in smoke from forest
fires in the northern U.S., and finished on
November 29 in a full-blown blizzard. I
spent 84 of a possible 95 days at the site. At
the end of October the site was assailed by a
series of storms, producing very high
winds, snow, and wind-chill temperatures
below -50º C.
Despite the weather, the combined
species total of 7217 birds was the highestever western Canadian raptor count by over
1000 birds, and the Golden Eagle tally
(4400) was apparently the third-highest
total counted anywhere in the world. On
October 25, 2006 we recorded our 100,000th
Golden Eagle at the principal observation
site, and it took us only 23,255 count-hours
to do it! A 30-day count for comparison
purposes at Mount Lorette, spearheaded by
Cliff Hansen, demonstrated that 45% more
Golden Eagles passed the South
Livingstone site in the period. The count
was an unqualified success, but because of
the poor weather I felt certain that we had
not yet seen it at its best.
Spring 2007 saw the main count effort
Photo: Cliff Hansen
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BIRDWATCH CANADA
return to Mount Lorette for the 15th
consecutive year. In 83 days we tallied the
lowest spring Golden Eagle total ever, just
2141 birds, which continued a declining
trend that started in about 1995. To put it
another way, the average count from 199395 was 4165 Golden Eagles tallied over an
average of 544 hours per season; the
average for 2003-07 was 2566 birds
counted in 1135 hours a season.
Analysis of age classes of migrant
raptors in fall counts at Mount Lorette show
a remarkably close correlation with the
number of birds fledged in Denali National
Park, Alaska in a long-term study
conducted by Carol McKintyre, which in
turn correlate closely with the snowshoe
hare population cycle in the north. The
declining trend in our fall eagle counts
appears to be related to over-winter survival
rates of young birds in their principal
wintering areas, which are mainly in the
western Great Plains of the U.S. and
northern Mexico, and in the Intermountain
Basin of Idaho, Utah, and Nevada. Our
counts indicate that up to 65% of juvenile
birds flying south fail to return north in the
spring. The reasons for this are almost
certainly various, but could be linked to
human population growth and drought in
the wintering areas. Spring population
trend data from western North American
sites are currently being analyzed to get a
clear picture of the situation. A recently
completed analysis of fall data also
indicates a diminishing trend for the
species.
I continue to study the migrations of
this wonderful bird because of what such
top predators can tell us about the
environment we share with them. But this is
not the only reason. There is the sheer
beauty of the wild places where I watch
these majestic birds for seven months of the
year, and the companionship of those with
whom I share the experience. There are also
the opportunities for teaching people to see
and hear the everyday miracles that
surround them, and my daily opportunity to
learn in what I think of as the ‘Open
University.’ There are the close encounters
with eagles, cougars, and bears, and with
butterflies, spiders, and plants.
It turns out that the traditional Piikani
Blackfoot name for the ridge system on
which the South Livingstone site is located
is Piitaistakis, meaning the Place of the
Eagles. Now we call the site PiitaistakisSouth Livingstone. Some things were just
meant to be.
Peter Sherrington is the Research Director
of the Rocky Mountain Eagle Research
Foundation. Visit www.eaglewatch.ca to
learn more.
La place des aigles
N
ous savons depuis longtemps
qu’au cours de sa migration,
l’Aigle royal passe par la
cordillère occidentale, mais jusqu’à tout
récemment, nous ne possédions aucune
autre précision sur ce parcours. Au cours
des années 1970 et 1980, presque toutes
les observations de l’Aigle royal pendant
sa migration ont été effectuées dans la
région des contreforts, en Alberta. On
estimait alors que les rares observations
dans les Rocheuses de grands nombres de
ces aigles en cours de migration étaient
exceptionnelles.
Il y a seize ans, Des Allen et moi
avons réalisé un recensement général des
oiseaux dans la vallée de Kananaskis, qui
est située à l’ouest de Calgary. Le 20 mars
1992, nous avons dénombré plus de 100
Aigles royaux longeant les chaînons
frontaux des montagnes Rocheuses, en
Alberta. Les oiseaux planaient au-dessus
du mont Lorette, puis disparaissaient le
long des crêtes situées au nord-ouest.
Pendant les sept autres jours consacrés au
recensement dans cette zone, au
printemps, nous avons observé un total
de 389 Aigles royaux effectuant le même
parcours.
L’automne de la même année, je me
suis de nouveau rendu au mont Lorette
avec un groupe de bénévoles. Nous avons
pu alors confirmer que ce parcours
faisaient aussi partie intégrante de la voie
migratoire vers le sud. Nous nous
sommes rapidement rendu compte qu’il
s’agissait bel et bien d’une migration
d’adultes que de jeunes oiseaux. Au cours
des quinze années qui ont suivi, nous
avons dénombré les rapaces migrateurs
au mont Lorette tout au long du
printemps et de l’automne. Nous avons
pu constater que le nombre d’oiseaux
atteignait un pic en mars et en octobre et
que la migration s’étendait de la mifévrier à la fin de mai, au printemps, et de
la fin d’août à la mi-décembre, à
l’automne.
Les observations de reconnaissance
effectuées à d’autres endroits en 1994
nous ont permis de déterminer que deux
« groupes » d’Aigles royaux se
déplaçaient en parallèle. Nous nous
sommes alors demandé si les deux
groupes se rassemblaient à un endroit
particulier pour former la concentration
la plus importante d’Aigles royaux. Nous
avons exploré diverses zones, mais ce
n’est qu’au bout de plusieurs années que
nous avons trouvé un lieu où les Aigles
royaux étaient plus nombreux qu’au
mont Lorette.
En 1998, Doug et Teresa Dolmen ont
amorcé des dénombrements de
reconnaissance dans un site qu’ils ont
baptisé « South Livingstone » soit
Livingstone Sud. (Puisque le nom
traditionnellement attribué par les Piikanis
de la nation des Pieds-Noirs au système de
crête à cet endroit est Piitaistakis, qui
signifie « la place des aigles », nous parlons
donc maintenant de Piitaistakis-South
Livingstone.) D’une altitude de 1900 m, ce
lieu se trouve à l’extrémité sud du chaînon
Livingstone, près de la ville de Frank, dans
le pas du Nid-de-Corbeau. Les résultats
obtenus en 1999 et 2000 étaient
prometteurs. Le 8 octobre 2000, Doug et
Teresa y ont dénombré 1071 Aigles royaux.
Ce nombre étonnant d’Aigles royaux
demeure le plus élevé qui ait été répertorié
en une seule journée.
le plus faible d’Aigles royaux qui n’ait
jamais été recensé (2141), ce qui suivait
l’importante tendance à la baisse
observée sur les lieux à compter de 1995.
En automne de 2007, où a eu lieu le
deuxième dénombrement échelonné sur
tout l’automne à South Livingstone,
nous avons observé près de 8300 rapaces
de 17 espèces distinctes en cours de
migration. Ce nombre englobait 700
Pygargues à tête blanche, 1219 Éperviers
bruns, 166 Autours des palombes, 188
Buses à queue rousse, 35 Faucons
pèlerins et un total remarquable de 5445
Aigles royaux.
Je continue d’étudier la migration
de ces prédateurs de niveau trophique
supérieur, mais non pas seulement en
raison des précieux renseignements que
Tableau 1. Dénombrements d’échantillons au mont Lorette.
Période de
dénombrement
Automne de 1999
Automne de 2000
Automne de 2006
Automne de 2007
Durée
(jours)
9
5
95
100
À South Livingstone, le premier
dénombrement ayant duré tout l’automne a
été réalisé en 2006 grâce au généreux appui
de la Enbridge et de la Crowsnest
Conservation Society. En dépit d’un certain
nombre de tempêtes qui ont eu lieu en
octobre, le dénombrement a connu un franc
succès. Par rapport aux résultats d’un
recensement de 30 jours effectué au mont
Lorette à des fins de comparaison, le
pourcentage d’Aigles royaux ayant passé
par South Livingstone était supérieur de
45 %.
Au printemps de 2007, le recensement
principal a de nouveau eu lieu au mont
Lorette. Nous avons alors relevé le nombre
Total des Aigles
royaux relevés
1137
1304
4400
5445
ceux-ci nous permettent de recueillir au
sujet de notre environnement. Tous les
ans, pendant sept mois, je profite de la
beauté des paysages à l’état sauvage où
j’observe les aigles, de la compagnie des
bénévoles se consacrant au projet et des
occasions quotidiennes de partager mon
savoir et d’acquérir des connaissances
nouvelles.
Peter Sherrington est directeur de
recherche de la Rocky Mountain Eagle
Research Foundation, qui a été
incorporée en société sans but lucratif en
1997. Pour plus de renseignements au
sujet de la fondation, veuillez consulter
son site à l’adresse www.eaglewatch.ca.
Tableau 2. Dénombrements d’échantillons à South Livingstone.
Période de
Durée (jours)
dénombrement
Automne de 1992
33
Printemps de 1993
48
Automne de 1993
75
Printemps de 1994
70
Automne de 1994
70
Automne de 2000
94
Total des Aigles
royaux relevés
2044
4140
4599
4213
3836
4753
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