Introduction 2011
is the 21th consecutive year that a spring raptor count
has been conducted at the Mount Lorette site. In 1992 an 8-day
reconnaissance count established that Golden Eagles moved to the
north in significant numbers through the Rocky Mountain Front Ranges.
Most of the birds moved along the Fisher Range, crossing the
Kananaskis Valley to Mount Lorette before continuing their migration
to the northwest. A 48 day (393 hour) count at the site in the spring
of 1993 yielded 4140 migrating Golden Eagles and the following year a
70 day (649 hour) count produced 4213 birds which remains the highest
spring count ever for the species at Mount Lorette. Between 1994 and
2007 extensive spring counts averaging 82 days (897 hours) were
conducted at the site with a maximum count in 2005 of 94 days (1238
hours). Despite the steady increase in observer effort during this
period, the number of migrating Golden Eagles counted has steadily
and significantly decreased since 1995. In 2006 RMERF conducted it
first complete fall count at the Piitaistakis-South Livingstone site
near the Crowsnest Pass in SW Alberta and in 2008-10 also conducted
full spring counts there. During this period extensive comparative
counts were made at Mount Lorette between March 1 and April 15 which
is coincident with the height of the Golden Eagle migration and
during which period over 90% of the population moves north. Observer
effort from 2008-10 at Mount Lorette averaged 43 days (487 hours)
with a maximum count of 46 days (519 hours) in 2010 when no days were
lost to inclement weather. In 2011 the count period was extended by
1 week (March 1 to April 22) and we plan to observe during the same
period this spring.
Cliff Hansen is again
coordinating the Lorette count this spring and would welcome
volunteers to assist the Principal Observers at the site. If you are
interested in helping you can contact him at 403-673-2422 or
403-609-0691 (cell), or just turn up at the site with your binoculars
and warm clothing!
March 1 [Day 1]
(Cliff Hansen, assisted by Kevin Barker and Chris Hunt). There was
only 1-2 cm of patchy snow in the Hay Meadow at the start of the
count despite above average snowfall on the mountains to the west.
The temperature at 0900 was -15C that rose to -3C at 1500 and was -6C
at 1700. Ground winds were initially E 0-3 km/h, then NE, ENE and
finally N 5-15 km/h, while ridge winds appeared to be moderate W. It
was initially cloudless but by 1000 cloud cover was 60% cumulus,
altostratus and cirrus and after1200 it was 100% stratus and
altocumulus until the end of the day. Snow started at 1700 after
which all ridges were obscured. The only migrant raptor was an early
subadult Golden Eagle at 1334, although single adult non-migrant Bald
Eagle and Northern Goshawk were also recorded. A flock of about 30
White-winged Crossbills was seen near the parking area. 10.33 hours
(10.33) GOEA 1 (1) TOTAL 1 (1)
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