Bombus sylvestris
In 3 days ~20% in a week ~40%
Bombus sylvestris, known as the forest cuckoo bumblebee or four-coloured cuckoo bee, is a species of cuckoo bumblebee, found in most of Europe and Russia. Its main hosts are Bombus pratorum, Bombus jonellus, and Bombus monticola. As a cuckoo bumblebee, Bombus sylvestris lays its eggs in another bumblebee's nest. This type of bee leaves their young to the workers of another nest for rearing, allowing cuckoo bumblebees to invest minimal energy and resources in their young while still keeping the survival of their young intact.
Bombus sylvestris belongs to the order Hymenoptera. Specifically, the species falls under the family Apidae, which further subdivides into the subfamily Apinae, and then the tribe Bombini. This is a small bumblebee; the queen has a body length of 15 mm (0.59 in) and the male one of 14 mm (0.55 in). The head is round, and the proboscis is short. Its fur is black with a yellow collar and a white tail. Sometimes the bumblebee can have a few pale hairs on top of its head, its scutellum, and/or on its tergite (abdominal segment). The male is variably melanistic. Those rarely found in northern Scotland... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cairngorms National Park | 🇬🇧 United Kingdom |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Manchester | 🇬🇧 United Kingdom |
With luck
About 10% of wildlife watchers report a Forest Cuckoo Bumble Bee sighting in Cairngorms National Park on a given day, based on 11 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 165th most-seen of the 300 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.
May to August
In those months about 10% of wildlife watchers report a Forest Cuckoo Bumble Bee in Cairngorms National Park on a given day, against under 5% in September to April, the lowest months.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Forest Cuckoo Bumble Bee sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Only Cairngorms National Park, in our data
Cairngorms National Park is the only park on Wallace's Line with enough records to rate Forest Cuckoo Bumble Bee sightings: about 10% of wildlife watchers there report one on a given day.
Same genus: Bombus
The closest relatives of the Forest Cuckoo Bumble Bee that you can see in Cairngorms National Park (genus Bombus, Bumble Bees) are Mountain Bumble Bee (about 30%), Common Carder Bumble Bee (about 20%) and Early Bumble Bee (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Forest Cuckoo Bumble Bee is recorded against all the insects logged in Cairngorms National Park (11 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.
