Strix nebulosa
Silhouette: Sharon Wegner-Larsen · PhyloPic
In 3 days ~20% in a week ~40%
The great grey owl (Strix nebulosa) (also great gray owl in American English) is a true owl, and is the world's largest species of owl by length. It is distributed across the Northern Hemisphere and is the only species in the genus Strix found in both Eastern and Western Hemispheres.
Adults have large, rounded heads with grey faces and yellow eyes with darker circles around them. The underparts are light with dark streaks; the upper parts are grey with pale bars. This owl does not have ear tufts and has the largest facial disc of any raptor. A white collar or "bow-tie" is just below the beak. The long tail tapers to a rounded end.
In length, the great grey owl is believed to exceed the Eurasian eagle-owl and Blakiston's fish owl as the world's largest owl. The great grey is outweighed by those two species and several others, including most of the genus Bubo. Much of its size is deceptive, since this species' fluffy feathers, large head, and the longest tail of any extant owl obscure a body lighter than that of most other large owls. The length ranges from 61 to 84 cm (24 to 33 in), averaging 72 cm (28 in) for females and 67 cm (26 in) for males. The wingspan can... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Elk Island National Park | 🇨🇦 Canada | |
| 2 | Riding Mountain National Park | 🇨🇦 Canada | |
| 3 | Yellowstone National Park | 🇺🇸 United States | |
| 4 | Yosemite National Park | 🇺🇸 United States | |
| 5 | Grand Teton National Park | 🇺🇸 United States | |
| 6 | Banff National Park | 🇨🇦 Canada |
With luck
About 10% of wildlife watchers report a Great Gray Owl sighting in Grand Teton National Park on a given day, based on 12 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 80th most-seen of the 185 birds we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
December
In that month about 40% of wildlife watchers report a Great Gray Owl in Grand Teton National Park on a given day, against under 5% in January–April, July, September and November, the lowest months. That is one of Grand Teton National Park's wettest months, with about 85 mm of rain against 20 mm in July.
Between 6 and 9 pm
Across all the parks we cover, that three-hour window holds the most Great Gray Owl sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
5th of 6
Of the 6 parks where we can rate Great Gray Owl sightings, Grand Teton National Park ranks 5th at about 10%. The best odds are in Elk Island National Park (Canada, about 30%), Riding Mountain National Park (Canada, about 20%) and Yellowstone National Park (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Great Gray Owl is recorded against all the birds logged in Grand Teton National Park (12 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
