Bombus flavifrons
In 3 days ~20% in a week ~40%
Bombus flavifrons, the yellow-fronted bumble bee or yellowhead bumblebee, is a species of bumblebee. It is native to North America, where it is distributed across much of Canada, Alaska, and the western contiguous United States.
This is a robust bumblebee; the queen has a body length between 13 and 16 mm (0.51 and 0.63 in) and a wingspan of 27 to 34 mm (1.1 to 1.3 in), the male is 11 to 12 mm (0.43 to 0.47 in) in length with a wingspan of 25 to 26 mm (0.98 to 1.02 in), and the workers are 9 to 12 mm (0.35 to 0.47 in) in length and 19 to 27 mm (0.75 to 1.06 in) in wingspan.
The yellow-fronted bumble bee has a dense, untidy fur. The head is yellow with black hairs intermixed on the posterior part, the thorax has a mixed black and yellow colouration, often (always with the queen) with a black, central field. The first two terga (abdominal segments) are yellow, on the females often with a black, central field on terga 1 to 2. Terga 3 and 4 are red, and the tail black, sometimes with yellow fields.
Subspecies Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Wrangell-St. Elias National Park | 🇺🇸 United States | |
| 2 | Kluane National Park | 🇨🇦 Canada | |
| 3 | Great Bear Rainforest | 🇨🇦 Canada | |
| 4 | Pacific Rim National Park Reserve | 🇨🇦 Canada | |
| 5 | Glacier National Park | 🇺🇸 United States | |
| 6 | Denali National Park | 🇺🇸 United States | |
| 7 | Olympic National Park | 🇺🇸 United States | |
| 8 | Grand Teton National Park | 🇺🇸 United States | |
| 9 | Rocky Mountain National Park | 🇺🇸 United States | |
| 10 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 11 | Banff National Park | 🇨🇦 Canada | |
| 12 | Yellowstone National Park | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Yellow-Fronted Bumble Bee sighting in Portland on a given day, based on 61 verified sightings from GBIF citizen-science data. It is the 106th most-seen of the 507 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.
March and May–July
In those months about 10% of wildlife watchers report a Yellow-Fronted Bumble Bee in Portland on a given day, against under 5% in April and August–February, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Yellow-Fronted 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.
4th of 6
Of the 6 cities where we can rate Yellow-Fronted Bumble Bee sightings, Portland ranks 4th at about 10%. The best odds are in Anchorage (United States, about 20%), Vancouver (Canada, about 20%) and Seattle (United States, about 10%).
Same genus: Bombus
The closest relatives of the Yellow-Fronted Bumble Bee that you can see in Portland (genus Bombus, Bumble Bees) are Black-Tailed Bumble Bee (about 20%), Yellow-Faced Bumble Bee (about 20%) and Fuzzy-Horned Bumble Bee (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Yellow-Fronted Bumble Bee is recorded against all the insects logged in Portland (61 verified sightings), 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.
