Bombus occidentalis
In 3 days ~30% in a week ~50%
Bombus occidentalis, the western bumble bee, is one of around 30 bumble bee species present in the western United States and western Canada. A recent review of all of its close relatives worldwide appears to have confirmed its status as a separate species.
Western bumble bee workers have three main color variations. The first color variation is found from northern California, north to British Columbia, and east to southwest Saskatchewan and Montana. B. occidentalis in these areas have yellow hair on front part of thorax. They are also marked by black hair segments on the basal section of the fourth abdominal segments have black hair and whitish lower edge of the fourth and fifth abdominal segments. In addition, they also have sparse whitish hairs that may appear black on the sixth abdominal segment, and an entirely black head.
The second color variation is found along the central coast in California. It has yellow hair on the sides of the second abdominal segment and all of the third abdominal segment and a reddish-brown hair on fifth abdominal segment.
The third color variation is found from the Rocky Mountains to Alaska. It has yellow hair on the thorax behind the... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Grand Teton National Park | 🇺🇸 United States | |
| 2 | Glacier National Park | 🇺🇸 United States | |
| 3 | Great Bear Rainforest | 🇨🇦 Canada | |
| 4 | Yellowstone National Park | 🇺🇸 United States | |
| 5 | Olympic National Park | 🇺🇸 United States | |
| 6 | Rocky Mountain National Park | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Western Bumble Bee sighting in Glacier National Park on a given day, based on 20 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 43rd most-seen of the 147 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.
June to September
In those months about 10% of wildlife watchers report a Western Bumble Bee in Glacier National Park on a given day, against under 5% in October to May, the lowest months.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Western 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 Western Bumble Bee sightings, Glacier 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 Western Bumble Bee that you can see in Glacier National Park (genus Bombus, Bumble Bees) are Vancouver Bumble Bee (about 20%), Black-Tailed Bumble Bee (about 20%) and Yellow-Fronted Bumble Bee (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Western Bumble Bee is recorded against all the insects logged in Glacier National Park (20 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.
