Dinosaur Ridge - Denver Field Ornithologists (15 Sep 2025) 7 Raptors
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Sep 15, 2025, 6:49:53 PM (3 days ago) Sep 15
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Dinosaur Ridge - Denver Field Ornithologists
Golden, Colorado, USA
Weather:
The surface forecast was for light winds from the SSW gradually changing to ESE, no cloud cover initially, but gradually increasing. Earth.nullschool.net predicted winds aloft at 11 km/hr from the SW. At the watch, the winds were light from the SSW. Radar showed the precipitation within clouds moving from WSW to ENE. In the second and third hours there were cumulogenic thermals to the west with some cirrus clouds mixed in. Cumulus clouds are between 2000 and 20,000 feet, higher in more arid and mountainous areas such as the Front Range. Cirrus clouds are 15,000 to 30,000 feet high. By the 3rd hour, these clouds reached 2 and 3 binocular fields above the ridge to the west, which is itself c. 10 degrees above ground level. Some of these clouds were 10 degrees across, and a few even 20 degrees (10 degrees is the width of a fist held out at arm's length)
Raptor Observations:
Exploratory fall hawk count 2025. See https://groups.google.com/g/cobirds/c/Oznn4uc6MBk The first migrant was a juvenile Northern Harrier at 10:13 AM MDT high over the western ridge, progressively rose in a thermal to very high without even a flap, I needed a scope to identify it. I was lucky finding a CH which I saw in my scope while looking at a distant TV. Non migrant raptors: juvenile GE at 10:06AM hunting on the SE slope of Lookout Mountain, with a white tail base, but no white on its wing. I have seen it before. TV 2. RT 2. When I saw raptors with binoculars while I was seated, and when I got up to find them in my scope, close to a specific cloud, I completely lost sight of them and could not find them even with binoculars again, probably because our eyes "accommodate" by unconsciously changing the shape of our eye lenses, and when we stand up the lens probably reverts to a different shape resulting in difficulty finding the raptor again. Some of the raptors I could see with binoculars and scope to be rising rapidly in thermals, and suddenly they could not be seen at all - presumably they were higher than the resolution of my eyes even with magnification. I checked the blue sky and the clouds up to 3 binocular fields above the western ridge and did not find any many migrants, using Jerry Liguori's suggestion of scanning with binoculars in the shape of a battlement. I stayed an extra 0.5 hour to check this idea, I expected to see no raptors during that half hour, which was true. With an excellent soaring forecast with the rate of lift of 5.5 /sec and predicted maximum height of thermals being 12,185 feet (2.3 miles) above ground level, I was expecting that migrant raptors would be soaring very very high today, beyond the ability of binoculars to even find them, and I hoped that I may be able to see a few of them before they got too high. I actually saw a TV rising in a thermal to the level of the capping cumulus cloud, after which it closed its wings and streamed south (there would not be any lift above the cloud). On days with a perfectly blue sky in the past as well as in spring when the migration seems to stop after an hour or two, I always assumed that they were flying much higher than I could even spot them with binoculars. Today, I could actually see the process where migrants which were moderately to high would be seen with magnification only when they were face-on, and disappear when they were edge-on, and suddenly disappear into the blue sky when they got higher in a thermal. Some of the Raptors were only dots in binoculars, and I could categorize them as to genus with a scope, and sometimes even identify the species, they were so high/far away today. I could have stayed till 4:00 PM when thermals get lower and some migrants could be seen somewhat lower, but I have a subscription to hear the Takacs Quartet and today is their first recital at CU Boulder this evening.
Non-raptor Observations:
Common Raven 3, American Robin 5.
Predictions:
The surface forecast predicts partly sunny with a high near 75 F, cloud cover 31% increasing to 66% at noon with a chance of thunderstorms. Earth.nulllschool.net predicts winds aloft locally at 10 km/hr from the west, while the winds a distance west of the watch from the SE at 26 mph, and further east of the watch at 34 m/hr from the South.
Report submitted by Official Counter of the day shown above (dinor...@gmail.com)
Dinosaur Ridge - Denver Field Ornithologists information may be found at: www.dinosaurridgehawkwatch.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. American 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
Hawk Counter(s) and volunteers from March through early May.
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)
Golden, Colorado, USA
| Daily Raptor Counts: Sep 15, 2025 | |||
| Species | Day's Count | Month Total | Season Total |
| Black Vulture | 0 | 0 | 0 |
| Turkey Vulture | 1 | 5 | 9 |
| Osprey | 0 | 1 | 1 |
| Bald Eagle | 0 | 1 | 1 |
| Northern Harrier | 1 | 3 | 3 |
| Sharp-shinned Hawk | 1 | 8 | 13 |
| Cooper's Hawk | 2 | 10 | 12 |
| American Goshawk | 0 | 0 | 0 |
| Red-shouldered Hawk | 0 | 0 | 0 |
| Broad-winged Hawk | 0 | 0 | 0 |
| Red-tailed Hawk | 0 | 5 | 18 |
| Rough-legged Hawk | 0 | 0 | 0 |
| Swainson's Hawk | 1 | 17 | 67 |
| Ferruginous Hawk | 0 | 0 | 0 |
| Golden Eagle | 0 | 2 | 4 |
| American Kestrel | 1 | 21 | 27 |
| Merlin | 0 | 0 | 0 |
| Peregrine Falcon | 0 | 1 | 2 |
| Prairie Falcon | 0 | 1 | 3 |
| Mississippi Kite | 0 | 0 | 0 |
| Unknown Accipitrine | 0 | 0 | 0 |
| Unknown Buteo | 0 | 6 | 8 |
| Unknown Falcon | 0 | 0 | 0 |
| Unknown Eagle | 0 | 0 | 0 |
| Unknown Raptor | 0 | 2 | 3 |
| Short-eared Owl | 0 | 0 | 0 |
| Total: | 7 | 83 | 171 |
| Observation start time: | 08:30:00 |
| Observation end time: | 11:30:00 |
| Total observation time: | 3 hours |
| Official Counter | Ajit Antony |
| Observers: |
Weather:
The surface forecast was for light winds from the SSW gradually changing to ESE, no cloud cover initially, but gradually increasing. Earth.nullschool.net predicted winds aloft at 11 km/hr from the SW. At the watch, the winds were light from the SSW. Radar showed the precipitation within clouds moving from WSW to ENE. In the second and third hours there were cumulogenic thermals to the west with some cirrus clouds mixed in. Cumulus clouds are between 2000 and 20,000 feet, higher in more arid and mountainous areas such as the Front Range. Cirrus clouds are 15,000 to 30,000 feet high. By the 3rd hour, these clouds reached 2 and 3 binocular fields above the ridge to the west, which is itself c. 10 degrees above ground level. Some of these clouds were 10 degrees across, and a few even 20 degrees (10 degrees is the width of a fist held out at arm's length)
Raptor Observations:
Exploratory fall hawk count 2025. See https://groups.google.com/g/cobirds/c/Oznn4uc6MBk The first migrant was a juvenile Northern Harrier at 10:13 AM MDT high over the western ridge, progressively rose in a thermal to very high without even a flap, I needed a scope to identify it. I was lucky finding a CH which I saw in my scope while looking at a distant TV. Non migrant raptors: juvenile GE at 10:06AM hunting on the SE slope of Lookout Mountain, with a white tail base, but no white on its wing. I have seen it before. TV 2. RT 2. When I saw raptors with binoculars while I was seated, and when I got up to find them in my scope, close to a specific cloud, I completely lost sight of them and could not find them even with binoculars again, probably because our eyes "accommodate" by unconsciously changing the shape of our eye lenses, and when we stand up the lens probably reverts to a different shape resulting in difficulty finding the raptor again. Some of the raptors I could see with binoculars and scope to be rising rapidly in thermals, and suddenly they could not be seen at all - presumably they were higher than the resolution of my eyes even with magnification. I checked the blue sky and the clouds up to 3 binocular fields above the western ridge and did not find any many migrants, using Jerry Liguori's suggestion of scanning with binoculars in the shape of a battlement. I stayed an extra 0.5 hour to check this idea, I expected to see no raptors during that half hour, which was true. With an excellent soaring forecast with the rate of lift of 5.5 /sec and predicted maximum height of thermals being 12,185 feet (2.3 miles) above ground level, I was expecting that migrant raptors would be soaring very very high today, beyond the ability of binoculars to even find them, and I hoped that I may be able to see a few of them before they got too high. I actually saw a TV rising in a thermal to the level of the capping cumulus cloud, after which it closed its wings and streamed south (there would not be any lift above the cloud). On days with a perfectly blue sky in the past as well as in spring when the migration seems to stop after an hour or two, I always assumed that they were flying much higher than I could even spot them with binoculars. Today, I could actually see the process where migrants which were moderately to high would be seen with magnification only when they were face-on, and disappear when they were edge-on, and suddenly disappear into the blue sky when they got higher in a thermal. Some of the Raptors were only dots in binoculars, and I could categorize them as to genus with a scope, and sometimes even identify the species, they were so high/far away today. I could have stayed till 4:00 PM when thermals get lower and some migrants could be seen somewhat lower, but I have a subscription to hear the Takacs Quartet and today is their first recital at CU Boulder this evening.
Non-raptor Observations:
Common Raven 3, American Robin 5.
Predictions:
The surface forecast predicts partly sunny with a high near 75 F, cloud cover 31% increasing to 66% at noon with a chance of thunderstorms. Earth.nulllschool.net predicts winds aloft locally at 10 km/hr from the west, while the winds a distance west of the watch from the SE at 26 mph, and further east of the watch at 34 m/hr from the South.
Report submitted by Official Counter of the day shown above (dinor...@gmail.com)
Dinosaur Ridge - Denver Field Ornithologists information may be found at: www.dinosaurridgehawkwatch.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. American 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
Hawk Counter(s) and volunteers from March through early May.
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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