McKay's Bumble Bee | NWT Species at Risk

McKay's Bumble Bee

formerly Western Bumble Bee, mckayi subspecies

Bombus mckayi

NWT List of Species at Risk:

No status

NWT SARC Assessment:

Data Deficient

Federal Species at Risk Act list:

Under Consideration

COSEWIC Assessment:

Special Concern

NWT General Status Rank:

Sensitive

Description:

McKay's Bumble Bee is a medium-sized bumble bee. It has a short head and a band of yellow hair across the thorax in front of the base of the wings. Between the wings there is a black band or a large black central spot. The tip of the abdomen is almost always white. This northern species has longer hair overall and yellow hair behind the wings and on the third segment of the abdomen, which help to tell it apart from the Western Bumble Bee.

Length: Female queens, 1.6 to 1.9 cm (0.63 to 0.75 in); Female workers, 1.1 to 1.3 cm (0.43 to 0.51 in); Males, 1.0 to 2.0 cm (0.39 to 0.79 in)

Report McKay's Bumble Bee sightings to WILDLIFEOBS@gov.nt.ca

Check out the Field Guide to Bumble Bees of the Northwest Territories

Distribution

McKay's Bumble Bee is found the western mountains of the NWT as well as northern British Columbia, Alaska and Yukon.

Range map information

Habitat and biology

McKay’s Bumble Bee used to be a subspecies of Western Bumble Bee but is now considered a distinct species.

McKay's Bumble Bees use a wide range of habitats, as long as flowers and nest sites are available. The colony usually nests underground in abandoned rodent burrows or within hollows in decaying wood. The queens overwinter in loose soil or rotting trees.

All members of the McKay's Bumble Bee colony die in the winter except for the new queens. They leave the colony, mate, hibernate and emerge the following spring to establish new colonies.

Bumble bees play a crucial role in transferring pollen between plants, allowing fertilization which is essential for fruit and seed production.

Population size and trends

Recent surveys suggest this northern species is still common. However, the closely related southern species Western Bumble Bee is experiencing a serious population decline. Because the reasons for the southern decline are unknown, there is cause for concern for McKay's Bumble Bee as well.

Threats

Potential threats in the Northwest Territories include: a high parasite load compared to other bumble bee species; introduction of exotic bumble bee species for pollination, which can spread diseases to native bees; and the use of pesticides and herbicides. At high densities, imported honey bees can outcompete native bumble bees for pollen.

Protection and recovery

In 2019, the NWT Species at Risk Committee assessed this species as Data Deficient. This means there was not enough information to determine the status in the NWT.

COSEWIC assessed this species as Special Concern in Canada in 2014.

Area:

Dehcho, Sahtú

Status Report and Assessment of Western Bumble Bee, Yellow-banded Bumble Bee, and Gypsy Cuckoo Bumble Bee in the NWT (2019)

Links:

Field Guide to Bumble Bees of the Northwest Territories