Bombus sitkensis
In 3 days ~20% in a week ~40%
Bombus sitkensis, the Sitka bumblebee, is a species of bumblebee common in western North America from Alaska to California. The Sitka bumblebee has an oblong head with a medium-length proboscis. The females (queens and workers) have black and yellow hairs intermixed on the face and forward part of the thorax and a black patch in the middle of the thorax, while their sides are yellowish. Terga (abdominal segments) 1 and 2 are yellow, and 3 and 4 black, the latter with a yellow posterior rim. The two last terga are brownish-red. The male has the face and forward parts of the thorax yellow, and only the posterior parts are darker (black and yellow intermixed). On the abdomen terga 1 and 2 are yellow, and terga 3 to 5 yellow on the anterior part, black on the posterior. The tail (terga 6 to 7) is brownish-red.
The species is a common bumblebee found in the western North America from Alaska and British Columbia, and Washington, to northern Idaho, western Montana, and the coastal parts of California. The Sitka bumblebee has experienced mild population declines in parks in California due to competition with the yellow-faced bumblebee (B. vosnesenskii) for... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Great Bear Rainforest | 🇨🇦 Canada | |
| 2 | Pacific Rim National Park Reserve | 🇨🇦 Canada | |
| 3 | Redwood National Park | 🇺🇸 United States | |
| 4 | Olympic National Park | 🇺🇸 United States | |
| 5 | Glacier National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Vancouver | 🇨🇦 Canada | |
| 2 | Seattle | 🇺🇸 United States | |
| 3 | San Francisco | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Sitka Bumble Bee sighting in Redwood National Park on a given day, based on 7 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 62nd most-seen of the 101 insects 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.
June
In that month about 20% of wildlife watchers report a Sitka Bumble Bee in Redwood National Park on a given day, against under 5% in April and August–February, the lowest months. That is one of Redwood National Park's driest months, with about 50 mm of rain against 360 mm in January.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Sitka 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.
3rd of 5
Of the 5 parks where we can rate Sitka Bumble Bee sightings, Redwood National Park ranks 3rd at about 10%. The best odds are in Great Bear Rainforest (Canada, about 20%) and Pacific Rim National Park Reserve (Canada, about 20%).
GBIF citizen-science records
It is estimated from how often the Sitka Bumble Bee is recorded against all the insects logged in Redwood National Park (7 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.
