Busy as a bee, literally counting bees

Along with other bee species, bumblebees are facing major population declines. WDFW is helping to monitor and address the situation through bee surveys.

A bumblebee warms up to fly away after being studied by biologists.
A bumblebee warms up to fly away after being studied by biologists.

Bumble bees; not only are they the darlings of the bee world, but also very important to agriculture.

“The majority of wild flowering plants that feed wildlife, and two-thirds of the crop plants that feed us, depend on insect pollinators,” said WDFW wildlife biologist Carrie Lowe. “In our part of the world, bees do most of the work.”

Bumble bees, along with their relative the honeybee, are experiencing a population decline due to a variety of factors, including disease, parasites, habitat loss, and pesticides. Their decline, and the decline of all native pollinators, is a big threat to agriculture.

The Washington Department of Fish and Wildlife (WDFW), with support from a federal State Wildlife Grant, is part of the effort to document and fight that decline. This summer, WDFW biologists partnered with the Xerces Society, a conservation organization specializing in invertebrate species, and others on the Pacific Northwest Bumble Bee Atlas. The Atlas is a series of bumble bee surveys to help determine which types of bumble bees are in the area and what plants they frequent.

In eastern Washington, Lowe and other staff members conducted surveys recently at two WDFW wildlife areas. While there are dozens of bumble bee species in the Pacific Northwest, the surveying trips turned up five species, including the common Nevada bumble bee (Bombus nevadensis) and the Central bumble bee (Bombus centralis).

The Nevada bumble bee is native to North America, from Alaska to California in the west and east to Wisconsin, as well as Arizona and New Mexico. It has a long tongue and short, dense fur. The thorax is yellow, sometimes with a hairless black spot in the middle.

The Central bumble bee is found in Canada and the western United States. It is orangish-red near the end of its abdomen with a yellow thorax.

Probably the most difficult part of surveying bees is catching them. It can make people who have spent a lot of time pursuing higher education look like children again. While some jump into the air to net bees as they fly overhead, examining flowering plants for bumble bees collecting pollen generally proves more effective.

The preferred method has biologists spotting a bee on a plant, and then gently placing a net overtop. The bee is directed into the end (pointed part) of the net, then carefully and patiently worked into a vial. The vial has air for the bees to breathe so there is no harm to them from being in it for a little while.

The vials are placed in a cooler where cold temperatures slow their movements. Several minutes in the cold puts bees into a sleep-like state.

“Cooling the bee slows them down enough for us to get a good look at the bees’ head, thorax, and abdomen. Color patterns on these parts allow us to identify them by species.” said Lowe.

Using a makeshift “lab” on the side of the road - a seat in the dirt and the lid of the cooler for a table - Lowe identifies each bee, photographs it extensively, and records information such as what type of plant each was found on.

At the same time, another staff member fills out paperwork identifying all the plant types observed in the area. Photographs and a special smart phone app are used for this when needed. Plant information is important to the future of bumble bee because, once they learn how to get pollen out of a particular flower, they tend to return to that kind of plant, going from plant to plant pollinating each. Pollen from the flowers is stored in a ball on the bee’s legs.

After each bumble bee is processed, it is gently placed in the sun, or on the hand of a volunteer if available, to warm up.

“Bumble bees have the ability to generate their own heat,” said Lowe. “So they can warm themselves up with movements that look like flexing their legs and shivering. This is fairly unique among insects.”

After a few minutes of this, the bee lifts off much like a helicopter, then zips away.

The short period of contact with cooler temperatures has no long-term effect on the bees.

Data gathered from these surveys is submitted to the Xerces Society to be compiled, analyzed, and used in efforts to sustain and conserve bumble bee populations.

For those looking for their own way to help in the effort to preserve the species, consider something as simple as planting flowers, particularly native species, in your yard for bumble bees to collect pollen from, or minimize the use of pesticides (especially when flowers are blooming). Or, sign up to participate in the Pacific Northwest Bumble Bee Atlas and conduct your own surveys as a trained citizen scientist.

The Washington Department of Fish and Wildlife

Written by

The Washington Department of Fish and Wildlife is dedicated to preserving, protecting and perpetuating the state’s fish and wildlife resources.

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