Mount Lorette Raptor Count Spring 2013

Introduction 2013 is the 22^th 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.

March 1 [Day 1] (Cliff Hansen, assisted by Joel Duncan) It was a pleasant day for the start of the season with the temperature rising to 7C from a low of 2C as the result of a strong Chinook wind that produced nimbistratus cloud in early afternoon which periodically obscured the ridges and brought light rain. These conditions were obviously not condusive to migration and the only migrant seen was a late subadult Bald Eagle. 10 hours (10) BAEA 1 (1) TOTAL 1 (1)

November 15 [Day 52] (Cliff Hansen, assisted by Kevin Barker and Chris Hunt) The temperature was -6C at 0815, rose to a high of 2C at 1400, and was -1C at the end of the day. It was initially calm with NE winds 5-15 km/h developing after 1000, that gusted to 25 km/h around 1100 and became light after 1600. Ridge winds appeared to be mainly light, and it was essentially cloudless all day although up to 30% of the sky was covered by degrading aircraft condensation trails for much of the day. The final day of the fall 2012 count produced 6 migrant raptors between 0959 and 1542, the flight comprising 4 Bald Eagles (2a,1sa,1j) and 2 Golden Eagles of indeterminate age. All birds were flapping continuously and appeared to have trouble maintaining altitude. This is the sixth consecutive day that have produced two migrant Golden Eagles, and the six days following the two days of poor weather on November 8 and 9 yielded only 24 migrant raptors, including the 12 Golden Eagles. By contrast, the 7 days leading up to the poor weather event produced 370 migrants of which 305 were Golden Eagles. This strongly suggests that birds were moving ahead of the cold front that produced the two-day shut-down. Other birds seen included a female Green-winged Teal on the river, 1 juvenile Northern Shrike, 1 Golden-crowned Kinglet, 1 Pine Grosbeak and 1 Common Redpoll.

9 hours (530.09) BAEA 4 (128), GOEA 2 (2635) TOTAL 6 (2987)

The further adventures of “Elaine” Elaine spent several days, presumably hunting, about 10 km east of the central part of Canyon Ferry Lake, but by November 15 she had moved again to the NW and is presently east of the northern end of the lake, close to where she was on November 4.

MOUNT LORETTE PROVISIONAL FINAL COUNT, FALL 2012, with variance from long-term average in parenthesis, excluding incomplete counts in 1992, 1997, 2002, 2006-2008.

DAYS 52 (-5%)

HOURS 530.09 (-5.9%)

TURKEY VULTURE (TUVU) 0 (n/a)

OSPREY (OSPR) 2 (-26.3%)

BALD EAGLE (BAEA) 128 (-52.45)

NORTHERN HARRIER (NOHA) 6 (-42.9%)

SHARP-SHINNED HAWK (SSHA) 63 (-55.2%)

COOPER’S HAWK (COHA) 10 (-58.9%)

NORTHERN GOSHAWK (NOGO) 30 (-38.1%)

Unidentified Accipiter (UA) 5

BROAD-WINGED HAWK (BWHA) 1 (-86.3%)

SWAINSON’S HAWK (SWHA) 0 (n/a)

RED-TAILED HAWK (RTHA) 26 (-24.3%)

FERRUGINOUS HAWK (FEHA) 0 (n/a)

ROUGH-LEGGED HAWK (RLHA) 61 (+12.7%)

Unidentified Buteo (UB) 2

GOLDEN EAGLE (GOEA) 2635 (-27.3%)

Unidentified eagle (UE) 2

AMERICAN KESTREL (AMKE) 0 (n/a)

MERLIN (MERL) 5 (-30%)

GYRFALCON (GYRF) 1 (-68.2%)

PEREGRINE FALCON (PEFA) 6 (+12%)

PRAIRIE FALCON (PRFA) 2 (=)

Unidentified Falco (UF) 1

Unidentified raptor (UU) 1

TOTAL 2987 (-29.7%)

RMERF extends many thanks to Cliff Hansen for organizing a well-conducted fall 2012 count; to the five Principal Observers: George Halmazna (15 days), Terry Waters (11 days), Cliff Hansen (10 days), Bill Wilson (9 days) and Joel Duncan (7 days); and to the Assistant Observers and all the members and supporters who contributed to a very successful season.

November 14 [Day 51] (Cliff Hansen) The temperature was 0C at 0830, rose to a high of 4C at 1200 and 1300, and was 2C at the end of the day. Ground winds were mainly SW, 5-10 km/h, gusting to 25 km/h after 1100, 6-15 km/h after 1500 and becoming light at the end of the day, while ridge winds appeared to be moderate W all day. Cloud cover was 40-50% cumulus and altostratus until 1700 after which it was 20%. Despite excellent observing and migration conditions the only migrant raptors seen were two adult Golden Eagles gliding high above the Fisher Range at 1022. Other bird species recorded included 1 male Belted Kingfisher, 1 Northern Shrike, 1 Golden-crowned Kinglet, 3 Rusty Blackbirds and 2 Dark-eyed Juncos of the race cismontanus.

9 hours (521.09) GOEA 2 (3633) TOTAL 2 (2981)

November 13 [Day 50] (George Halmazna) It was the warmest day for about a week, with a starting temperature of -4C rising to a high of 5C at 1500 and remaining at 4C at 1600. Ground winds were SSW 2-5 occasionally gusting to 10 km/h to 1400 after which they were SW gusting 40 km/h before moderating again to 5-10 km/h at the end of the day, while ridge winds were moderate to strong SW day producing snow plumes. The east ridges were clear all day, but the west was 10-30% obscured until 1600 when it was 60% obscured by snow squalls. The only migrant raptors seen were 2 juvenile Golden Eagles seen at 0829 and 0929, although a non-migrant adult Bald Eagle and an non-migrant unaged Northern Goshawk were also noted. Other birds seen included 1 Belted Kingfisher, 1 Golden-crowned Kinglet, 15 Bohemian waxwings, 2 Pine Grosbeaks, 7 Red Crossbills, 22 Common Redpolls and 1 Pine Siskin.

9 hours (512.09 hours) GOEA 2 (2631) TOTAL 2 (2979)

November 12 [Day 49] (George Halmazna) The low temperature for the day was -9C at 1900, but it climbed to a high of 0C at 1700. Ground winds were SSW for most of the day, gusting to 30 km/h between 1100 and 1300, then 5-15 km/h to 1500 and gusting 30-40 km/h to 1600 before becoming SW 5-10 km/h for the rest of the day. Ridge winds were strong SW all day producing snow plumes. Despite ideal observing conditions, once again raptor movement was thin with only 4 birds recorded between 1038 and 1627. The flight comprised 1 adult Bald Eagle, 1 adult dark morph calurus Red-tailed Hawk and 2 adult Golden Eagles. A slow day was enlivened by a few songbirds that included 9 Golden-crowned Kinglets, 1 American Robin, 3 Dark-eyed Juncos, 1 female Rusty Blackbird, 3 Pine Grosbeaks, 7 Red Crossbills and 5 Common Redpolls.

10 hours (503.09) BAEA 1 (124), RTHA 1 (26), GOEA 2 (2629) TOTAL 4 (2977)  

November 11 [Day 48] (Bill Wilson) Clear skies allowed the temperature to fall to -23C at 0800, which is the lowest so far this season, but it rose to a high of -4C at 1400 and was -5C at the end of the day (1700). Ground winds were calm to very light SW to 1000 and thereafter calm to 10 km/h with occasional moderate gusts, while ridge winds were mainly moderate SW all day that produced snow pluming. The initial clear skies gave way to 10% cirrus at 0900 that increased to 70% by 1100, 90% altostratus and cirrus to 1300, and 100% altostratus to the end of the day. It was another disappointing day for raptors with only 7 birds (4 Bald Eagles (3a,1sa), 1 light morph Rough-legged Hawk and 2 adult Golden Eagles moving along the eastern route between 1120 and 1453. The main drama of the day came at 0855, when a Northern Shrike was seen closely pursuing a redpoll-sized songbird behind a spruce tree, so the outcome of the chase is unknown. Other birds observed included 6 Mallard, 2 Dark-eyed Juncos, 3 Pine Grosbeaks and 30 White-winged Crossbills.

9.67 hours (493.09) BAEA 4 (123), RLHA 1 (61), GOEA 2 (2627) TOTAL 7 (2973)

November 10 [Day 47] (Joel Duncan, assisted by Cliff Hansen) Despite the previous two days' weather there was only about 6 cm of fresh snow on the ground, but it remained cold. The temperature at 0900 was -14C, rose to a high of only -9C between 1400 and 1700 and was -11C at the end of the day. Ground winds were light NE or variable, to calm all day and ridge winds appeared to be light SW all day. An initial cloud cover of 90% altostratus quickly reduced to 10% cirrus and cumulus at 1100 and after 1400 cloud was present only in trace amounts. The calm conditions did not appear to favour raptor movement and only three migrants were seen: an adult Golden Eagle at 1318, an adult Bald Eagle at 1418 and an adult Golden Eagle at 1552. All birds were flapping along the Fisher Range at ridge level. A poor raptor flight was compensated by a flock of 16 Greater White-fronted Geese flying south at 1015 and an odd-looking junco in a flock of “Oregon” morphs that appeared to show the character of a “Grey-headed” Junco (J.h.caniceps), a subspecies that rarely occurs north of Colorado. Other species seen included 13 Canada Geese, 2 non-migratory Northern Goshawks (1a,1j),1 juvenile Northern Shrike, 7 Golden-crowned Kinglets, 5 Pine Grosbeaks and 6 Common Redpolls.

8.5 hours (483.42) BAEA 1 (119), GOEA 2 (2625) TOTAL 3 (2966)