“People don’t come to Denali and other parks in Alaska to watch bumblebees, but they should,” says Jessica Rykken, entomologist for Denali National Park and Preserve. The “last frontier” state may be known for its oversized wildlife, from bears to moose, but on a smaller scale, the diversity of bumblebees (or bumblebees, depending on who you ask) is exceptionally high and sustains food. entire ecosystems.
“Bringing in this next generation of plants to provide habitat for caribou, moose, or any large herbivore and then the carnivores that depend on them, it’s all tied to pollinators,” says wildlife biologist Casey Burns of the Office. of Land Management in Alaska. . “Without doubt, I think they are the most important group of wild animals for ecological function. “
Bumblebees aren’t the only pollinators native to the northernmost state of the United States. There are dozens of other native bee species, and native flies also play an important role (as do several species of butterflies). But the Alaskan bumblebees are distinguished both by their numbers – “We have a fairly low bee diversity overall, but we have a very high proportion of bumblebees,” says Rykken – and by the reasons for their success. And while many bumblebee species in Lower 48 are in decline, the Alaskan members of the genus Bombus seem to thrive. Now, researchers and environmentalists are embarking on an unprecedented effort to determine how many bees, including bumblebees, are buzzing around their huge and largely unstudied state. Alaska’s very first bee atlas project is underway and bumblebees will play a prominent role.
Of the nearly 50 species of bumblebee documented in the United States, nearly half are found in Alaska, including four species that are not found anywhere else in the country. Big body and covered in thick, insulating hair (during a Zoom call, Rykken holds a board of fat, furry, pinned specimens, some the size of his thumb), bumblebees have other cold weather survival skills , including, well, twerk. While bees in general can quickly vibrate their flight muscles, regardless of flight, to generate heat, bumblebees are particularly good at this.
“They use these flight muscles to raise their body temperature by 30 degrees in five minutes,” says Rykken. This rapid increase in heat allows them to fly in cold, even snowy weather, when other insects are pinned to the ground. And, while other social bees, including honey bees, will band together to keep their queen, brood, and others warm, bumblebees can survive solo. A Bombus the queen can effectively transfer the heat generated by her flight muscles into her abdomen to keep her eggs warm.
“They thermoregulate in a pretty amazing way,” says entomologist Derek Sikes, curator of the insect collection at the University of Alaska Museum. Sikes says bumblebees are “actually warm-blooded: they generate heat, it’s just not constant, like mammals do.” But it’s internal, not just basking in the sun.
The natural life cycle of Bombus the species adapts to the long winters and short summers of Alaska. In August, when the first frosts usually arrive, the queen begins a long hibernation underground, alone. It emerges in the spring, finds a nesting site, and produces female worker bees and eventually potential new queens and males to mate with them. As August approaches, successfully mated, the new queens will find a place to lie down during the winter. “Everyone – the old queen, the workers, the males – is dying,” says Rykken. While many other species of social bees overwinter in clusters of thousands, the bumblebee’s solo strategy requires fewer resources and is more efficient for their environment.