Bombus appositus
In 3 days ~30% in a week ~50%
Bombus appositus is a species of bumblebee known commonly as the white-shouldered bumblebee. It is native to western North America, including western Canada and the western United States. This species lives in open habitat, such as meadows and slopes. It nests underground or on the surface. Males congregate to seek mates. It feeds on a variety of plant taxa, including giant hyssops, thistles, gentians, owl's clovers, locoweeds, penstemons, and clovers. It especially favors subalpine larkspur (Delphinium barbeyi) and it serves as one of the plant's main pollinators.
This species has a range from southwestern Canada south to the Cascade Mountains and the Sierra Nevada, and west to central California. This species is a host to Bombus insularis, a species of cuckoo bumblebee. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Grand Teton National Park | 🇺🇸 United States | |
| 2 | Rocky Mountain National Park | 🇺🇸 United States | |
| 3 | Glacier National Park | 🇺🇸 United States | |
| 4 | Olympic National Park | 🇺🇸 United States | |
| 5 | Banff National Park | 🇨🇦 Canada | |
| 6 | Yellowstone National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Denver | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a White-Shouldered Bumble Bee sighting in Rocky Mountain National Park on a given day, based on 35 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 41st most-seen of the 191 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
May to August
In those months about 10% of wildlife watchers report a White-Shouldered Bumble Bee in Rocky Mountain National Park on a given day, against under 5% in September to April, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most White-Shouldered Bumble Bee sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 6 parks where we can rate White-Shouldered Bumble Bee sightings, Rocky Mountain National Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Grand Teton National Park (United States, about 10%).
Same genus: Bombus
The closest relatives of the White-Shouldered Bumble Bee that you can see in Rocky Mountain National Park (genus Bombus, Bumble Bees) are Hunt's Bumble Bee (about 10%), Nevada Bumble Bee (about 10%) and Colorado Black-Notched Bumble Bee (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the White-Shouldered Bumble Bee is recorded against all the insects logged in Rocky Mountain National Park (35 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.
