The Buzz About Summer

What’s warm, fuzzy, and announces the arrival of summer by humming? The answer: a queen bumblebee.

These remarkable animals are more common than you might think. Queens appear in Estes Park in mid-May, and are distinguished by their large size (.75 to 1 inch); black, yellow, orange, and white “fur”; and steady flying – even at times through spring snow showers.

But pay attention, queen bumblebees are only active for a few weeks, during the time that late spring becomes summer. At the altitude of Estes Park, queens are generally seen from early May to early June. On the tundra in Rocky Mountain National Park, they may be seen from mid-June to early July. In any given place the period when queens are active is limited to about four weeks.

As the title “queen” implies, these bees are all females. They survive the winter in a bark crevice or other sheltered place. When queen bumblebees emerge on a warm day in May, they immediately begin to forage on the nectar and pollen from early spring flowers such as currants, violets, barberry, bluebells, and willow catkins. And they also begin a “life or death” search for a nesting site to hold a new bumblebee colony.

Startlingly large relative to honeybees, queen bumble bees are most noticeable during their quest for a home. Watch the queen bumblebee as you would watch other wildlife, quietly, and perhaps with binoculars if she is several feet away. What you will see is a seemingly myopic queen stopping to explore any small crevice. She may even disappear momentarily into small cavities. The most desirable real estate for a bumblebee is an abandoned mouse hole – they have the best insulation - but other types of sheltered holes will serve. (Although large, queen bumblebees are not aggressive. They will only sting if directly threatened.)

Once a queen has chosen a nest site, she begins to provision it with the honey and pollen needed to feed her first brood of worker bees. When all is ready, she will lay eight-ten eggs directly on a clump of pollen. A wax cup nearby holds concentrated nectar that the queen feeds from during the night. The queen literally “broods” the eggs by placing her warm abdomen and thorax on the brood clump. She will also shiver her powerful wing muscles to raise the nest temperature. (On a cold spring night, think of these bumblebee queens and their long vigil.)

About three weeks after the queen establishes the nest the first workers emerge from the nest. After single-handedly raising the first brood, the queen remains underground, devoting the rest of the summer to egg laying. All bumblebees seen during the middle and later part of the summer are smaller in size and have no royal title.

The final phase of the queen’s life comes in late summer when she mates with male bees, commonly called drones, from her own hive. The offspring from these matings, the cumulative result of the effort over the summer by all members of the hive, are new queens. (More successful hives produce more queens.) Except for these young queens, all of the bees of the hive die. Already full grown, the queens will overwinter in an underground hole, or other sheltered place. Eight months later, the survivors emerge, warm and fuzzy, to found new colonies.