A lone Yellow-banded Bumblebee

On July 31st, armed with my camera, I patrolled the front and back yards. As I always say: “You never know what you’ll see in the garden!” In the backyard mini-meadow, I spotted an unusual-looking bumblebee. I took photos of it and headed inside to identify this new bee.

It appeared to be a Yellow-banded Bumblebee — a rare and declining species. Eager for an expert opinion, I fired off a few emails and submitted photos to Bumble Bee Watch and iNaturalist. Others confirmed that it was a Yellow-banded Bumblebee. If it had a yellow patch at the tip of its abdomen, the ID would be conclusive; however, Yellow-banded Bumblebees don’t always have this distinctive patch. I was very excited about our special bumblebee guest.

A celebrity bee

This Yellow-banded Bumblebee has continued to visit our back garden. I feel like a paparazzi because I’ve taken so many photos and videos of it.

Yellow-banded Bumblebees are medium-sized with alternating yellow and black bands. They look particularly round and fuzzy because of their short, even body hair and short heads. In one of my phone videos, I can see the bumblebee’s yellow moustache, indicating that it’s a male. Also, I’ve never seen this bee collecting pollen, as female workers do.

‘Special Concern’

Yellow-banded Bumblebees used to be one of our most common bumblebees, but their numbers have declined drastically since the 1990’s. Here in Southern Ontario, it is still observed, but it has declined to about 10% of its former numbers (York University study). In 2016, Ontario designated the Yellow-banded Bumblebee a species of ‘special concern’ that should be monitored closely. Why has it declined so dramatically? It’s complicated.

Habitat loss

Yellow-banded Bumblebees are habitat generalists. They live wherever the flowers and nest sites are — woodlands, wetlands, meadows, farmlands, and urban areas. Since they aren’t fussy, why is our changing landscape a problem?

Natural habitats have been cut, plowed, bull-dozed, and paved. Unfortunately, the province is now allowing this to continue unfettered by government controls, and without regard for threatened wildlife. The suitable habitat that remains is fragmented.

For bumblebees, that spells trouble because isolated populations become inbred. According to a York University study, Inbreeding and disease are factors in decline of Yellow-banded Bumblebee: “As bees become more inbred, they encounter difficulties maintaining their populations, but as their populations gets smaller, they have difficulties avoiding inbreeding. So that is one risk factor that could accelerate their decline.”

These study findings are supported by research into declining bumblebee species in Britain. Dave Goulson, founder of the British Bumblebee Conservation Trust, shares similar research conclusions in his easy-to-understand books A Sting in the Tale (available at Ottawa Public Library) and A Buzz in the Meadow (at OPL). When I recently re-read these books, I was startled by the similarities.

Parasites and diseases from managed bees

Early in May, on a birding bus trip to Point Pelee Provincial Park, I saw fields full of greenhouses, after greenhouses, after greenhouses… In the town where we stayed, the many surrounding greenhouses cast an eerie, orange glow on the clouds at night that looked like fire.

Many of these greenhouses grow tomatoes so we can have fresh ones in February, and Canadian-made ketchup. Greenhouse-grown tomatoes are pollinated by managed colonies of Common Eastern Bumblebees, and they tend to have more diseases than wild bees. When these managed bees escape and forage outside in the landscape, they spread disease when they visit the same flowers as wild bees. Again according to the York University study, Yellow-banded Bumblebee inbreeding has reduced their genetic diversity and made them particularly susceptible to diseases spread from managed bees.

Canada now has voluntary guidelines for greenhouse operators to reduce the risk of managed bumblebee escape, and thus reduce the spread of disease to wild bee populations (Bumblebee Sector Guide to the National Bee Farm-level Biosecurity Standard). I hope that these recommended procedures are being followed.

Pathogens and parasites also spill over from managed honeybee hives. Ontario has the highest number of registered beekeepers in Canada, and they help farmers pollinate crops. Increasingly, amateurs are taking up backyard beekeeping in a well-intended effort to help bee populations. (Ontario Species at Risk Evaluation Report for Yellow-banded Bumble Bee (Bombus Terricola)) Unfortunately, if honeybee problems aren’t identified and addressed quickly, they will also spread to, and harm, wild bee populations.

Picky eaters

Still, why are Yellow-banded Bumblebee populations affected more than other types of bumblebees? Some other bumblebee species’ numbers are stable, or even increasing. It turns out that flower preferences, and thus food availability, has also contributed Yellow-banded Bumblebees’ decline. They will visit a wide variety of plants for pollen to feed queen bumblebees and bumblebee larvae. However, they are fussier about the flowers they visit for nectar, their fuel.

A bumblebee’s tongue length determines which flowers it can reach into for nectar. Bumblebee species with long tongues are declining more quickly than others. Wait a minute…Yellow-banded Bumblebees have short tongues. In the podcast A Way to Garden, Beecology: how you can help native bumblebees, Robert Gegear explains that all of the species in decline are in the same functional group — they all visit flowers with longer, tubular flowers for nectar. The short-tongued bees, like Yellow-banded Bumblebees and Rusty-patch Bumblebees, have an innate behaviour called nectar robbing; they bite holes in the base of long flowers to reach the nectar. For more on nectar-robbing, read the Sting in the Tale.

Even though Yellow-banded Bumblebees are habitat generalists, much of Southern Ontario’s landscape is now poor quality habitat, devoid of the flowers these bumblebees need to survive.

Now that we know some reasons why Yellow-banded bumblebees have declined, what can we do to help them?

Plant the right flowers

The easiest thing we can do is plant lots of flowers for them. Since they don’t mind living in urban areas, we can provide new, quality habitat for them in our gardens. We need to include a variety of native plants, eliminate invasive plants and pesticides, and maintain our yards in pollinator-friendly ways.

Beecology is an American citizen science project similar to Bumble Bee Watch. Its website provides specific nectar plant recommendations for declining bumblebee species — the long-tongued bees, and short-tongued nectar robbers that also visit longer flowers. I will be using these recommendations to guide my next plant and seed choices.

Beecology also provides excellent suggestions for pollen-rich flowers used by all kinds of bees. Earlier in the summer, for several weeks, I had no bumblebees in my garden. One reason for their absence was that my garden was missing critical pollen sources. St. John’s wort, meadowsweet, and roses were blooming elsewhere and were covered in bees.

Support conservation organizations

What else can we do? To help maintain and restore habitats on a larger scale, for bumblebees and other wildlife, support conservation organizations. They are at the forefront of research and education, and they are pressuring governments on behalf of wildlife.

You can also help with citizen scientist projects. Bumble Bee Watch, a Wildlife Preservation Canada website, encourages you to submit bumblebee sightings. The data is used to help monitor bumblebee species range and populations, to better understand plant-pollinator interactions, and for other important research. Friends of the Earth also holds the Great Canadian Bumble Bee Count to gather data over a two-month period each summer. Now that I recognize the importance of these projects, I plan to contribute to them.

Hold governments accountable

It will take more than individuals and their urban gardens to restore bumblebee populations, and to protect other wildlife. Everyone needs to do their part, including governments, developers, farmers, and greenhouse operators. Sadly, Ontario’s current government is more interested in financial gain than conservation. Are developers considering wildlife and wilderness during construction? Are greenhouse operators following optional ‘biosecurity’ guidelines? Are farmers reducing harmful pesticides that kill insects and the birds that eat them. We must hold them all accountable. I now sign petitions, buy more organic produce, donate to conservation organizations, and I will vote accordingly.

All alone

It is now August 21st. When I last saw our Yellow-banded Bumblebee, he was tucked under a Joe Pye weed flower — his favourite spot to spend the night. This morning, I’ll check on him to see if he’s still around. I know that adult bumblebees don’t live very long, so I cherish every sighting.

For me, he will live on as a symbol. A symbol of the beauty and fragility of nature, and of what we risk losing if we don’t get our act together and take care of the environment. But he’s also a symbol of hope. There is obviously a thriving Yellow-banded Bumblebee nest somewhere nearby that grew large enough to produce queens and males. That’s a good sign. If I can provide habitat for a lone bumblebee, together we can create habitat for many more.