ANIMAL ESTATE client 5.6: EDWARD'S BUMBLEBEE
FOR ANIMAL ESTATE 5.0: PORTLAND, OREGON
SCIENTIFIC NAME: Bombus edwardsii
ANIMAL PROFILE: Bumble bees are incredibly important pollinators of wild flowering plants, as well as of agricultural crops. As generalist foragers, they do not depend on any one flower type. However, in turn, some plants do rely on bumble bees to achieve pollination. (link): http://xerces.org/bumblebees/index.html
As stated in Welcoming Wildlife To the Garden, providing homes for bumble bee species is a particularly worthwhile gesture, especially in light of declining populations with the ever expanding presence of human development. Though they only produce enough honey for their own purposes, they are an indispensable element to a garden.
RANGE: Western Nearctic regions. Northern and Northwestern North America.
HABITAT: Cascade mixed forest, coniferous forest, alpine meadow. Abandoned nests of hole-nesting birds are used by bumble bees that dwell above ground. They may also take up residence in empty rodent holes underground.
COMMUNITY: Bumble bees are native to the US, the only native species of bees that are social. They live in seasonal colonies, where fertilized queen bees are the only ones who survive and hibernate through winter. In these colonies, every member contributes to the well being of the group.
HOME CONSTRUCTION: Bumblebees will colonize in wooden nest-boxes, similar to the ones used by cavity-nesting birds.
BUILDING MATERIALS: The Xerces society suggests making a simple wooden box with internal dimensions of about 7" x 7" x 7" using preservative free lumber. There should be ventilation holes near the top, covered with door screen to deter ants. Drainage holes should be drilled at the bottom. The box should have an entrance tunnel that can be made from 3/4" pipe. The inside should have a layer of cotton batting for bees to cling to. The box should be weather tight to prevent larvae from becoming cold and to prevent the growth of mold and fungus.
A more full description of building nests for native bees put out by The Xerces Society can be found here.
THREATS: The bumble bee in general faces numerous threats. While some species have seen a dramatic decline in population, others may have recently become extinct. According to The Xerxes Society, "The major threats to bumble bees include: spread of pests and diseases by the commercial bumble bee industry, other pests and diseases, habitat destruction or alteration, pesticides, invasive species, natural pest or predator population cycles, and climate change." (link): http://xerces.org/bumblebees/index.html
INTERESTING FACTS: They perform a behavior called "buzz pollination," in which the bee grabs the pollen producing structure of the flower in her jaws and vibrates her wing musculature causing vibrations that dislodge pollen that would have otherwise remained trapped in the flower's anthers. Some plants, including tomatoes, peppers, and cranberries, require buzz pollination.
REFERENCE:
Another site with nest box construction details