RMERF counts March 1-3

MOUNT LORETTE, BEAVER MINES and STEEPLES RAPTOR COUNTS

SPRING 2019

www.eaglewatch.ca

PETER SHERRINGTON

Introduction 2019 is the 28th consecutive year that a spring raptor count has been conducted at the Mount Lorette site. In 1992 an eight-day reconnaissance count starting on March 20 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. 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 (2018) spring count saw a combined species passage of 2715 birds that included a Golden Eagle count of 2390. The March combined species count of 1794 represented 66.1% of the total count and was 18.1% below average, while April’s count of 596 was 34.9% above average and represented 33.9% of the count.  The maximum Golden Eagle count was 307 on March 25 and 6 other days had counts exceeding 100 birds. Bald Eagles (216) and Sharp-shinned Hawks (25) were close to average counts; 4 species were above average: Osprey (3), Broad-winged Hawk (3), American Kestrel (2) and Gyrfalcon (7), while 9 species occurred in below-average numbers: Northern Harrier (1), Cooper’s Hawk (2), Northern Goshawk (11), Red-tailed Hawk (30), Rough-legged Hawk (16), Golden Eagle (2390), Merlin (3), Peregrine Falcon (1) and Prairie Falcon (2). The combined species median passage date was March 26, 4 days later than average.

Last year saw the third complete (55 days) count at Beaver Mines which produced a record 2340 migrants of 18 species: 1 Turkey Vulture, 3 Ospreys, 355 Bald Eagles, 24 Northern Harriers, 46 Sharp-shinned Hawks, 6 Cooper’s Hawks, 27 Northern Goshawks, 13 Broad-winged Hawks, 2 Swainson’s Hawks, 155 Red-tailed Hawks, 6 Ferruginous Hawks, 101 Rough-legged Hawks, 1533 Golden Eagles, 10 American Kestrels, 14 Merlins, 9 Gyrfalcons, 10 Peregrine Falcons, and 3 Prairie Falcons. This year will be the fifth consecutive count at the site which is conducted from Peter Sherrington’s house in Beaver Mines.

Vance Mattson’s 2018 40-day reconnaissance count at the Steeples site on the western flanks of the Rocky Mountains near Cranbrook, BC produced a record 891 birds of 10 species. This year will be the ninth consecutive count at the site.

Rosemary Power is organizing the Mount Lorette count and welcomes visitors to the site. If you are interested in volunteering as a “Sky-sweeper” (no previous experience needed: just good eyes and binoculars) or as an Observer please contact Rosemary at 403-707-6117 (rosemarypower1010@gmail.com). Details of how to find the site and other useful information can be found on our website, www.eaglewatch.ca.  Generally the best time to see migrating eagles is in the afternoon, and the chart below gives an indication of the dates when other raptors are expected to be moving at the site.

Friday, March 1 Mount Lorette (Caroline Lambert) NO OBSERVATION (weather). Snow fell until early afternoon, but the mountains remained obscured all day. The temperature was -16C to -18C and winds were moderate ENE-NE all day.

Friday, March 1 Beaver Mines (Peter Sherrington) NO OBSERVATION (weather). Light snow fell for most of the day with an accumulation of 16 cm. The ridge was obscured until 1800 when the snow finally stopped. The temperature was -15C at 0800 but fell throughout the day to -23C at 1800 with moderate E to ENE winds up to 30 km/h giving wind chill temperatures of -31C to -33C after 1100. Clear skies are forecast for tomorrow.

Friday, March 1 Steeples (Vance Mattson) NO OBSERVATION (Weather). Light snow fell for most of the day and the mountains were fully obscured.

Saturday, March 2 Mount Lorette [Day 1] 0930-1145 Mount Allan viewpoint, 1155-1510 Hay Meadow, 1545-1720 Mount Allan viewpoint (Blake Weis). The temperature at 0930 was -30C and the high at 1200 was -25C that persisted for the rest of the day. Ground winds were N-NE all day, 0-5 km/h in the morning and 0-10 gusting to 20 km/h in the afternoon that produced wind-chill values close to -40C. Because of this Blake wisely spent the start and end of the day watching from his car at the Mount Allan viewpoint on highway 40. The sky was essentially cloudless with up to 10% cumulus developing close to ridges which were clear all day. Not surprisingly no migrant raptors were seen but a resident subadult Bald Eagle flew low to the south above the Kananaskis River at 1500. Despite the conditions a good variety of other bird species were noted comprising 1 female Common Merganser on the river, 1 male Hairy Woodpecker, 3 Common Ravens, 2 Mountain Chickadees, 3 Boreal Chickadees, 1 Golden-crowned Kinglet, 1 Brown Creeper, 2 Pine Grosbeaks (heard), 1 Common Redpoll and 10 White-winged Crossbills.

7.58 hours TOTAL 0

Saturday, March 2 Beaver Mines [Day 1] 0730-1815 (Peter Sherrington, assisted by Hilary Atkinson). The temperature at 0730 was -35C (wind-chill of -46C), the high was -24C at 1500 and 1600 and at 1815 it was -30C. Winds were light all day, W-NW to 1400 and E-ESE thereafter, and it was cloudless all day apart from traces of cumulus cloud to the SE. Two migrant raptors were seen: a juvenile Bald Eagle flapped low towards the north at 1201, and at 1611 a juvenile Golden Eagle also flapped to the north after perching atop a Douglas Fir for 50 minutes near the top of the ridge. Other birds seen were 6 Downy Woodpeckers, 1 male Red-shafted Flicker, 8 Blue Jays, 4 Black-billed Magpies, 42 Common Ravens most of which flew high towards the SW to roost in the late afternoon, 8 Black-capped Chickadees, 32 Evening Grosbeaks, 17 Common Redpolls, 8 Pine Siskins and 7 Dark-eyed Juncos (3 hyamelis, 1 cismontanus and 3 montanus).

10.75 hours BAEA 1, GOEA 1 TOTAL 2

Saturday, March 2 Steeples [Day 1] 1230-1630 (Vance Mattson). The temperature was -12C but it was calm and sunny with 20-30% cumulus cloud cover. There was 38 cm of snow at the site which made accessing the site challenging. No migrants were seen but a resident adult Golden Eagle glided north along the ridge and then west above the valley at 1310.

4 hours TOTAL 0

Sunday, March 3 Mount Lorette [Day 2] 0950-1805 (Bill Wilson, assisted by Lori Anderson). The starting temperature was -23C, the high was -11C at 1500 and it was -16C at the end of observation. Ground winds were E-ESE 2-8 km/h to 1200, NNW-NNE 5-14 to 1700 after which they were W 2-8 km/h and ridge winds were probably mainly moderate NW although cloudless skies all day made them difficult to determine. The only migrant was an adult Bald Eagle that flapped and glided to the north against the face of the Fisher Range at 1632. Other birds seen were 1 Black-billed Magpie, 2 Common Ravens, 2 Mountain Chickadees, 2 Common Redpolls and 5 White-winged Crossbills. There were 5 visitors to the site.

8.25 hours (15.83) BAEA 1 (1) TOTAL 1 (1)

Sunday, March 3 Beaver Mines [Day 2] 0730-1830 (Peter Sherrington, assisted by Hilary Atkinson). It was another very cold day with a temperature at 0800 of -34C (wind chill -46C), a high of -20C from 1400 to 1700 and -23C at 1830. Winds were W 15 km/h to 0900 then light and variable for the rest of the day. The sky was completely cloudless all day. The only migrant raptor was a dark morph Rough-legged Hawk that was initially seen feeding on a snow bank from where it flew low to the north at 1226. A non-migrant juvenile Bald Eagle flew to the SW at 1147 and an adult briefly perched on the ridge at 1815 before flying low behind the ridge presumably to roost for the night. Other birds seen were 6 Downy Woodpeckers, 2 Red-shafted Flickers (male and female), 10 Blue Jays, 9 Black-billed Magpies, a flock of 9 American Crows, 92 Common Ravens 77 of which flew high towards the SW to roost between 1500 and 1756, 7 Black-capped Chickadees, 3 Mountain Chickadees, 12 Bohemian Waxwings, 29 Evening Grosbeaks, 12 Common Redpolls, 40 Pine Siskins and 8 Dark-eyed Juncos (4 hyamelis, 1 cismontanus and 3 montanus).

11 hours (21.75) RLHA 1 (1) TOTAL 1 (3)

Sunday, March 3 Steeples [Day 2] 1230-1600 (Vance Mattson). The temperature was -12C that warmed to -9C under cloudless sunny skies, and it was calm. No migrants were seen, but a juvenile Golden Eagle moved south along the ridge, perched briefly and continued to the south after being harassed by a Clark’s Nutcracker.

3.5 hours (7.5) TOTAL 0 (0)