Piitaistakis and Mount Lorette Raptor Watch Spring 2010

The Piitaistakis (South Livingstone Ridge)and Mt. Lorette Raptor Counts for the spring migration of 2010 are underway. Follow the daily movement of raptors in these field notes by Research Director Peter Sherrington and his citizen scientist colleagues.

Friday, May 21, 2010

May 21 [Day 88] (Valley View site) Strong W winds continued to prevail so I decided to spend the last day of the count at the Valley View site where the temperature briefly reached a high of 9C at 1600 from a low of 1C at 0700. The ground winds were W-SW gusting 40-60 km/h for most of the day moderating slightly after 1500 but still occasionally gusting to 45 km/h in the late afternoon, and ridge winds were strong W all day. Cloud cover was 40-70% cumulus for much of the day giving excellent observing conditions, with cirrus and then altostratus cloud developing to 80% after 1800. Three migrant raptors went north, which is a satisfying number to finish on: a juvenile Sharp-shinned Hawk at 1246, a subadult Bald Eagle at 1540 and a juvenile Golden Eagle at 1637. I was pleased that I ended my counting career with a Golden Eagle just as it started with a single Golden Eagle seen at Mount Lorette at 1130 on March 20, 1992, for I have decided that this spring will be my last count. A female Red-winged Blackbird perched near the site at 0912 was the 86th species for the season and only the second time the species has occurred on a count here. Two more flocks of Canada Geese flew high to the east over the ridge today: 11 at 0944 and 16 at 1241. 12.5 hours (1015) BAEA 1 (396), SSHA 1 (82), GOEA 1 (2185) TOTAL 3 (3039)

May summary We spent 19 days in the field (13 at the Valley View site and 6 on the Piitaistakis Ridge) with 2 full days (May 5 and 6) lost to bad weather and 3 further days (May 3,4 and 8) significantly curtailed for the same reason. The number of days is 11.6% below the 2008-9 average and the number of hours (215.8) is 18.74% below average. The combined species total of 242 is 36% below average and only 6 species had counts that were above average: Osprey 16 (+60% and a new high count for the month), Broad-winged Hawk 13 (+100% and a new high count), Swainson’s Hawk 4 (+14.3%), Rough-legged Hawk 1 (+100% and equaling previous high monthly count), American Kestrel 5 (+11.1%), Merlin 2 (equaling the counts of the previous two years) and Peregrine Falcon 4 (+60%). All other species occurred mainly in significantly lower than average numbers: Turkey Vulture 2 (-55.6%), Bald Eagle 20 (-9.09%), Northern Harrier 8 (-46.7%), Sharp-shinned Hawk 40 (-53.5%), Cooper’s Hawk 5 (-72.2%), Northern Goshawk 3 (-86.7%), Red-tailed Hawk 25 (-47.9%), Ferruginous Hawk 2 (-42.9%), Golden Eagle 88 (-25.74%) and Prairie Falcon 2 (-42.9%).

Final Count (February 15 to May 21)
(Percentage variance from average spring 2008-2009 Piitaistakis-South Livingstone counts in parenthesis)

DAYS 88 (+2.9)
HOURS 1015 (+3.1)

OSPREY (OSPR) 20 (-9.1)
BALD EAGLE (BAEA) 396 (-11)
Unidentified Accipiter (UA) 5 (=)
Unidentified Buteo (UB) 2 (-33)
GOLDEN EAGLE (GOEA) 2185 (-23.57)
Unidentified eagle (UE) 3 (-45)
MERLIN (MERL) 11 (-48)
Unidentified Falco (UF) 0 (-100)
Unidentified raptor (UU) 0 (-100)

TOTAL 3039 (-24.41)

Principal Observers: Peter Sherrington (73 days and 7 partial days), Bill Wilson (6 days), Denise Coccioloni-Amatto (1 day and 4 partial days), Doug and Teresa Dolman (1 day), and Dawn Hall (3 partial days), with assistance from Keith McClary (40 days), Nel Van Kamer (32 days), Denise Coccioloni-Amatto (32 days), David Thomas (24 days), Dawn Hall (8 days), Pat Lucas (3 days), Doug and Teresa Dolmen (2 days), Phil Nicholas (2 days), Jan Aikins (1 day), Karole Michalsky (1 day), Paul Vandervelde (1 day), Wilbert Tripp (1 day), Patricia Wagenaar (1 day), Jocelyn Thomas (1 day), Elizabeth Miles (1 day) and Bob Simons (1 day).

Acknowledgements: To the members and supporters of the Rocky Mountain Eagle Research Foundation for their continuing financial support, and to members of the Crowsnest Conservation Society for their support and many contributions to the success of the project. To Dale and Karen Paton who welcomed us to watch from their property near the base of the ridge (the “Valley View” site) until the snow finally melted sufficiently to allow us to watch from the ridge top, to Denise Coccioloni-Amatto, David and Jocelyn Thomas, Mary-Lou and Jennifer Campbell, and Chris McMurdo for their many dinner invitations and understanding of my indecently early departures in order to write and publish the daily blog, and to Nel Van Kamer who generously provided pre-prepared dinners that allowed me more time to sleep than would have otherwise been the case.

Thursday, May 20, 2010

May 20 [Day 87] (Piitaistakis Ridge site) Strong W winds prevailed all day only rarely dropping below 40 km/h and gusting 50-70 km/h to 1800 when they were 60-70 gusting 90 km/h, diminishing to gusts of 80 km/h at 1900. The temperature was 1C to 2C to 1400 when it rose to 3.5C and then reached the day’s high of 5C from 1500 to1700 when a period of snow reduced the temperature back to 1C for the rest of the day. With the high winds it meant that wind-chill temperatures were below freezing for much of the day. Cloud cover was 100% altostratus and cumulus to 1400 after which the cloud broke to 60-70% cumulus, altostratus and altocumulus. Snow flurries that occasionally developed into brief periods of snow swept constantly down from the Continental Divide after 1245. Not surprising considering the weather, raptor migration was limited to subadult Golden Eagles gliding north at 1435 and 1448 and a juvenile doing the same at 1540. At 1136 what at first appeared in the distance to be high flying falcon surprisingly turned out to be the season’s first Mallard (a drake) [species #84] that flew high to the north above the ridge, and 3 minutes previously another “bachelor” flock of 15 Canada Geese had flown high to the east. At 1706, in the middle of one of the more enthusiastic snow flurries I found a Swainson’s Thrush [species #85] looking as if it regretted having left South America: I sympathized! Tomorrow will be the last day of the count, but where I shall be watching from will depend on the weather! 12.75 hours (1002.5) GOEA 3 (2184) TOTAL 3 (3036)

Wednesday, May 19, 2010

May 19 [Day 86] (Piitaistakis Ridge site) The strong winds that started late yesterday continued throughout today with W-WNW winds 35-50 gusting 60 km/h to noon, diminishing to gusts of 35-50 km/h in the afternoon. The winds made the starting temperature of 6C feel rather cool after several days of warm weather and the high was only 12.5C at 1600, but it felt warmer as 100% cumulus, altostratus and cirrus cloud gradually cleared to 5-30% cumulus and cirrus in the afternoon providing plenty of sunshine. Despite the good migrating and observing conditions only 7 migrant raptors occurred between 0907 and 1610: 1 adult Bald Eagle, 2 juvenile Sharp-shinned Hawks, 1 juvenile Cooper’s Hawk, 1 juvenile Red-tailed Hawk, 1 subadult Golden Eagle and 1 probable juvenile female Prairie Falcon. Because of the high winds other bird species were hard to find, but for the second day in a row a flock of Canada Geese flew high to the east above the ridge: 12 at 1259 yesterday and 35 at 1325 today. These flocks almost certainly comprise unmated male birds. 12.58 hours (989.8) BAEA 1 (395), SSHA 2 (81), COHA 1 (17), RTHA 1 (121), GOEA 1 (2181), PRFA 1 (14) TOTAL 7 (3033)

Tuesday, May 18, 2010

May 18 [Day 85] (Piitaistakis Ridge site) The temperature was 14.5C at 0800 and rose to the day’s high of 18C at 1300, winds to 1300 were often calm or variable and light, and cloud cover was 70-80% cumulus, altostratus and cirrus. At 1245 a dark cumulonimbus cloud rapidly developed to the SW and at 1312 a thunderstorm broke bringing steady rain that lasted until 1540. The storm appeared to be stationary overhead with continuous thunder and lightening for over 2 hours and although spectacular it was not exactly enjoyable! By 1520 the temperature had fallen to 8C but recovered to12-13C after 1700. At 1700 another thunderstorm developed to the SSE and for the next 1.5 hours it moved slowly north just E of the ridge saving me from a second soaking. To finish the day WNW winds developed gusting to 50 km/h at 1900 and the day ended in sunshine as the cloud cover rapidly cleared. Before the storm only 5 migrant raptors moved: a juvenile Northern Harrier, 2 juvenile Sharp-shinned Hawks, 1 juvenile Red-tailed Hawk and a juvenile Golden Eagle. After the storm ended a second juvenile Northern Harrier with a full crop glided low along the ridge to the north at 1640, and just as I was beginning to give up on the day a juvenile Peregrine Falcon flew low overhead to the north at 1837. A Warbling Vireo singing near the parking area in the evening was the 83rd bird species of the year. The bad weather gave me time to look at the flowering plants on the ridge. Just a few days after the snow had finally melted there were extensive carpets of Western Spring Beauty, Glacier Lilies and Prairie Anemone, common Wyoming Kittentails, Yellowstone Draba, Pretty Shootingstars and early Yellow Buttercups, one patch of Yellowbells and single flowering Moss Phlox and Nine-leaved Desert-Parsley. With a dwindling number of raptor migrants and with deteriorating weather conditions forecast for the weekend I am now planning to end the count on Friday May 21.12.75 hours NOHA 2 (20), SSHA 2 (79), RTHA 1 (120), GOEA 1 (2180), PEFA 1 (4) TOTAL 7 (3026)

Monday, May 17, 2010

May 17 [Day 84] (Piitaistakis Ridge site) The ridge was almost snow-free and the remaining drifts at the site disappeared as the temperature reached 20.5C at 1700 from a low of 13C and was 16.5C at 1900. Winds were generally calm or light SW-WSW except for 1645-1730 when the wind was WSW 20-25 gusting 30 km/h, and cloud cover was 70-100% cirrus, cirrostratus and cumulus all day giving hazy sunshine and excellent viewing conditions. Between 0800 and 1400 each hour yielded one migrant raptor, the first 3 being an immature male richardsonii Merlin and 2 female American Kestrels. No migrants were seen between 1321 and 1645 at which time an adult light morph Swainson’s Hawk moved north with a Sharp-shinned Hawk followed 3 minutes later by 2 juvenile light morph Ferruginous Hawks, which is the first record of the species since April 1st. The commonest migrant, however, remained Golden Eagle with 3 subadults and 2 juvenile birds moving between 1227 and the last migrant of the day at 1833. The total bird count was 26 species, which is a marked improvement over the 11 recorded 4 days ago, and included 2 Violet-green Swallows which is only the second record for the ridge. Three Western White butterflies were new for the season. 12.5 hours (964.4) SSHA 2 (77), SWHA 1 (4), FEHA 2 (5), GOEA 5 (2179), AMKE 2 (5), MERL 1 (11) TOTAL 13 (3019)

Sunday, May 16, 2010

May 16 [Day 83] (Valley View site) It was another beautiful day with the temperature reaching a season high 22C at 1600 from a low of 5.5C: in fact the temperature remained above 20C from 1200 to 1730 and was still 18.5C at 1900. Ground winds were calm to 1030 and then mainly light W-WSW except between 1200 and 1430 when they occasionally gusted to 15-23 km/h, and ridge winds were WNW-W light to moderate. Cloud cover was a 60-100% mixture of cirrus, cirrostratus, cumulus and altocumulus giving hazy sunshine all day and yet again provided an excellent observation backdrop. There was a slow but steady migration of raptors with 12 birds of 8 species moving between 1151 and 1749 including the season’s 7th Turkey Vulture (an adult) and 3rd Swainson’s Hawk (a light morph adult). Other migrants were 1 subadult Bald Eagle, 1 juvenile Northern Harrier, 2 juvenile Sharp-shinned Hawks, 1 juvenile Cooper’s Hawk, 2 juvenile light morph Red-tailed Hawks and 3 Golden Eagles (1sa and 2j). Hunting and displaying resident Red-tailed Hawks were conspicuous through most of the day representing 3 or 4 pairs. The day’s second Golden Eagle at 1359 was the season’s 3000th migrant raptor, but we are heading for the lowest ever spring count at the site as the 2008 and 2009 totals were 4204 and 3837 respectively. A Calliope Hummingbird flying over at 1231 was the 82nd species of the season and a first spring record and a second unidentified hummingbird flew high overhead at 1805. Most remarkable was a small flock of 3 Common Redpolls at 0710 which is only the second record for the season (the other was 3 birds on March 8) and represents by far the latest ever record at the site. The exceptionally warm weather of the last three days appears to have significantly reduced the snow cover on the Piitaistakis Ridge, so I plan to return there to conduct the count tomorrow. 12.5 hours (951.9) TUVU 1 (7), BAEA 1 (394), NOHA 1 (18), SSHA 2 (75), COHA 1 (16), SWHA 1 (3), RTHA 2 (119), GOEA 3 (2174) TOTAL 12 (3006)

Saturday, May 15, 2010

May 15 [Day 82] (Valley View site) The temperature reached a season high 21C at 1400 from a low of 3C and was still 18C at 1900, ground winds were calm to SW gusting 30-40 km/h between 1100 and 1430 but less than 20 km/h for the rest of the day and ridge winds were WNW moderate to strong to 1500 and moderate W thereafter. The sky was initially cloudless with cumulus and cirrus developing after 0900 thickening to 80% cumulus between 1500 and 1600 that produced very light scattered showers before reducing to 30-60% for the rest of the day once again providing excellent observing conditions. It was the best raptor movement for 4 days with a total of 22 birds moving steadily between 0930 and 1904, the flight comprising 3 Bald Eagles (1a,2sa), 1 adult female Northern Harrier, 3 Sharp-shinned Hawks (2j,1u), 1 juvenile Northern Goshawk, 3 light morph Broad-winged Hawks (1a,1j,1u), 6 juvenile light morph calurus Red-tailed Hawks, 1 unidentified Buteo and 4 Golden Eagles (1a,1sa,2j). The total bird count was a season high 42 species which included first records [species #78-81] for Western Tanager, Cassin’s Vireo, Western Wood-Pewee (1st spring record for the site) and 2 Violet-Green Swallows (second spring record for the site). 12.33 hours (939.4) BAEA 3 (393), NOHA 1 (17), SSHA 3 (73), NOGO 1 (84), BWHA 3 (13), RTHA 6 (117), UB 1 (2), GOEA 4 (2171) TOTAL 22 (2994)