Date: 03/01/2017

Number: 1

MOUNT LORETTE, BEAVER MINES and STEEPLES RAPTOR COUNTS
SPRING 2017

www.eaglewatch.ca

PETER SHERRINGTON

Introduction: 2017 is the 26th consecutive year that a spring raptor count has been conducted at the Mount Lorette site. In 1992 an eight-day reconnaissance count at the site established that Golden Eagles moved to the northwest 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. March 20 will be the exact 25th anniversary of seeing the first migratory Golden Eagles at the Mount Lorette site and there will be a celebration event there to mark the date. A 48 day (393 hour) count at the site in the spring of 1993 yielded 4140 migrating Golden Eagles and the following year a seventy 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 and subsequent years the count period was extended by 1 week (March 1 to April 22) and we will use the same period this spring.
Last year’s (2016) spring count saw a combined species passage of 2866 birds that was the second highest since 2006, as was the Golden Eagle count of 2542: it should be noted, however, that all counts from 1993-2006 exceeded these totals. The March combined species count of 2500 represented 87.2% of the total count, while April’s count of 290 was 47.4% below average, but the April total of 290 was 50.8% below average. The maximum Golden Eagle count of 296 on March was the 3rd lowest ever, and 9 days had counts exceeding 100 birds including the second earliest ever on March 7. Five species occurred in significantly higher than average numbers: Northern Harrier (11), Northern Goshawk (11), Red-tailed Hawk (37), Rough-legged Hawk (39) and Merlin (9), while 6 other species were significantly below average. The combined species median passage date was March 18, 5 days earlier than average with 7 species moving earlier than average and just Red-tailed Hawk moving later.

Turner Valley, AB

Latitude: 51 Longitude: -115.1

Observed by: Claire
Contact Observer

The observer's e-mail address will not be disclosed.
Contact will be made through a web-based form.