Saturday, 24 December 2022

[cobirds] Dinosaur Ridge - Denver Field Ornithologists (24 Dec 2022) Raptors

Dinosaur Ridge - Denver Field Ornithologists
Colorado, USA

Daily Raptor Counts: Dec 24, 2022
SpeciesDay's CountMonth TotalSeason Total
Black Vulture000
Turkey Vulture000
Osprey001
Bald Eagle001
Northern Harrier001
Sharp-shinned Hawk002
Cooper's Hawk0013
Northern Goshawk000
Red-shouldered Hawk000
Broad-winged Hawk001
Red-tailed Hawk0022
Rough-legged Hawk000
Swainson's Hawk007
Ferruginous Hawk002
Golden Eagle0011
American Kestrel0010
Merlin000
Peregrine Falcon001
Prairie Falcon003
Mississippi Kite000
Unknown Accipiter000
Unknown Buteo001
Unknown Falcon001
Unknown Eagle000
Unknown Raptor001
Total:0078


Observation start time: 11:30:00
Observation end time: 13:30:00
Total observation time: 2 hours
Official CounterAjit Antony
Observers:



Visitors:
7 hardy hikers walking the Hogback Trail.

Weather:
Last Saturday I was doing a Christmas count in the Red Rocks area and our leader Greg Goodrich mentioned my having found two Golden Eagle on my last visit to Dinosaur Ridge, and hoping we would be able to add one of them to pick up. I facetiously commented on the plenty of free time he seemed to have in order to read my report which found no migrants. He said that negative reports are important information. That is the reason I keep going to the watch.. earth.nullschool.net showed the usual band of West winds in Southern Wyoming and northern Colorado at 30 to 52 km/h, which should again unfortunately push any migrants to the east of the watch. https://drive.google.com/file/d/1WhrKiVQbuY7yyckh7hPJQCNQkAK5q8Te/view?usp=drivesdk The green circle in the image denotes roughly the location of the hawk watch. You can see the Great Salt Lake to the WNW, and a line drawn a little above the south end of it and extended to the East roughly would be the Wyoming Colorado border where you can see the strong winds . There were Northwest winds predicted at the watch on weather.gov for Morrison CO, and while I know that this is not a guarantee of any migrants whatsoever, as a sentimental nod to Northwest winds in the East which bring in good migrants even in late December, I decided to go up to the watch wearing crampons. Also the temperature was predicted to be 47°F with a windchill of 43°F which could be bearable with 15 mph winds and even with 20 mph gusts.

Raptor Observations:
In the 1st hour I saw 4 raptors far to the NE, 2 of them were much larger than one which rose up and which I followed was an RT which kited a few times over Green Mountain and which I then lost â€" seemingly a non-migrant. When I went back to look at the larger presumed Eagles I could not find them â€" probably dropped. Much later I saw an RT kiting repeatedly over time into the wind to the NW and I watched it to make sure that it was indeed hunting. Last year counting at the I-84 Overlook Hawk Watch in New York we would see RT kiting into strong NW winds and a hawk watcher would say "They're local" to which I would say "Keep watching them" and invariably they would fly South. What was happening was that while the the North component of the wind would push them in the right direction, the West component would slow them down and push them back, and these RT would be "resting" by kiting into the wind, and then make another foray South, repeatedly kiting presumably to conserve energy. At 1:01 PM to the NNW I saw an adult Golden Eagle being harassed by a Common Raven with 2 RT beside them. Of course I followed the GE which rose up in the air at which point the RTs began escorting it out of their territory by soaring ahead and behind it until it decided to fly West (when they left it) and disappeared below the ridge against the pines beyond I-70.

Non-raptor Observations:
Townsend's Solitaire 1, Northern Flicker 1, House Finch 2.

Predictions:
This is my last count at this site for fall 2022. My hypothesis as to why this site has a good spring watch but not one in fall is not because of any geographic factors e.g. the Cape May Peninsula "facing the wrong way" in spring, but likely because of meteorological factors such as a band of very strong winds in fall either from the West or NW at a little North of the Colorado Wyoming border which likely push potential migrants to the East where they, early in the season perhaps meet the Denver Convergence Vorticity Zone and later in the season meet the presumed (with my limited meteorological knowledge) the high-pressure zone around Denver further pushing these Migrants east of Denver, bypassing the Dinosaur Ridge hawk watch completely. The hawk watch north of Denver which is further west is Commissary Ridge Hawk Watch and one south of Denver is the Manzano Mountains HawkWatch (where Emma Riley counted this fall) which is also West of Denver â€" both of which have good fall raptor migrations. Presumably do they don't have the aberrant and inhibitory winds that face this watch. If Bryan Guarente the meteorologist at UCAR/The COMET Program reads this, he may have an opinion to share.


Report submitted by DAVID HILL ()
Dinosaur Ridge - Denver Field Ornithologists information may be found at: http://www.dfobirds.org
More information at hawkcount.org: [Site Profile] [Day Summary] [Month Summary]




Site Description
Dinosaur Ridge is the only regularly staffed hawk watch in Colorado and is the
best place in the world to see migrating Ferruginous Hawks. Hawk watchers may
see 17 species of migrating raptors; and it is an excellent site to see rare
dark morph buteos including Broad-winged hawk, Swainson’s hawk, Ferruginous
hawk, Rough-legged hawk and Red-tailed Hawk. Other raptors we see include Golden
and Bald Eagles, Northern harrier, Osprey, Peregrine Falcons, Prairie Falcons,
Cooper's and Sharp-shinned Hawks, American Kestrels, Merlin, and Turkey
Vultures. Northern Goshawk is uncommon but also counted each season. Non-raptor
species include Rock Wren, Bushtit, Western Bluebird, Sandhill Crane,
White-throated Swift, American White Pelican, and Dusky Grouse. Birders of any
skill level are always welcome. The hawk watch at Dinosaur Ridge is staffed by a
Hawk Counter and volunteers from 9:30 AM to 5:30 PM from March 1st to May 14th,
weather permitting.

Directions to site:
From exit 259 on I-70 towards Morrison, drive south under freeway and take left
into first parking lot, the Stegosaurus lot. Follow hawk watch signs from the
southwest end of the parking lot to the hawk watch site. The hike starts heading
east on an old two-track and quickly turns south onto a trail on the west side
of the ridge. When the trail nears the top of the ridge, turn left, and walk to
the flat area at the crest of the ridge. (Distance: 0.56 miles, Elevation gain:
259 feet)

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