by Watershed Stewardship Assistant, Rachel Morris.
Alberta has more native pollinators than you might think! A whole host of solitary bees, social bees, wasps, and many more animals all pollinate our native and cultivated flowers. Many of them overwinter underground or in hollow stems, so a few small landscaping decisions can provide crucial habitat.
The Birds and the Bees
Pollination is the process of moving pollen from the male part of a flower (called the ‘anther’) to the female part (called the ‘stigma’), allowing the plant to make seeds. Pollen can be moved by wind or by animals. Any animal that carries this out can be called a ‘pollinator’. Many flowering plants produce nectar and brightly-coloured petals to attract pollinators.
While the first thing that comes to mind when we think of pollinators is often a bee, this is also carried out by wasps, flies, butterflies, moths, certain beetles, and even hummingbirds. The animals seek out flowers to eat the pollen and tasty nectar, and in return spread some of the pollen to the female part of the flower, as well as to other nearby flowers. This allows the flowers to make seeds so they can reproduce. Pollination is a classic win-win, also known as ‘mutualism’, a type of symbiotic relationship.
In addition to food in the summer, pollinators need overwintering habitat so they can return each spring. We will explore some of Alberta’s pollinators, how they spend their winters, and what you can do this fall to help them out.
The Home Team
Alberta’s native pollinators are a hugely diverse group of animals. Below is an outline of different groups that forage on nectar or pollen.
Bees
A leafcutter bee (left), and bumblebee (right). Leafcutter bees are solitary and bumblebees are social, but both feed on nectar and pollen. Photos via OWC.
Alberta is home to 375 native species of bees. All of these feed on pollen and nectar, and all play a vital role in pollination. While this includes thirty species of bumblebees, which are social, we have many smaller solitary bees. Adult solitary bees do not cohabitate in the same nest, instead foraging for themselves and their own eggs. These include miner bees, plasterer bees, sweat bees, mason bees, and one species of oil bee.
Wasps
Wasps are a diverse group, many of which are pollinators. Some wasps, such as the potter wasp pictured here, will eat other insects and carrion as well as nectar. Many wasps have fascinating life cycles, such as parasitoid wasps, which lay their eggs into another insect’s larva.
Flower Flies
A flowerfly. Photo via OWC, 2016
Flower flies, also called hover flies, are also important pollinators in Alberta. Many of them look a little like bees, although they only have two wings compared to a bee’s four, and their eyes are very large and fly-like. Many other types of flies also feed on flowers, including mosquitos, although they contribute less to overall pollination than bees.
A blister beetle feeding on curlycap gumweed. Photo by Maria Albuquerque, 2024.
Beetles
Several families of beetles are pollinators, including blister beetles, leaf beetles, and checkered beetles.
A gossamer-winged butterfly resting on white asters. Photo by Rachel Morris, 2024.
Butterflies
Alberta is home to home to 175 species of butterflies, of which 107 are local to the grassland region. While caterpillars may eat a range of plant materials, including stems and leaves, adult butterflies feed on nectar from flowers.
A hummingbird clearwing moth. Photo by pfaucher on iNaturalist.
Moths
Although some moths do not feed as adults, some are dedicated pollinators. For example, the hummingbird clearwing moth (Hemaris thysbe), an avid pollinator, is sometimes mistaken for a bumblebee due to its size and daytime foraging habits. It sips nectar from vetches and other deep flowers with its long proboscis (mouth part).
A rufous hummingbird. Photo by Ken Orich, 2017.
Hummingbirds
We of course can’t forget hummingbirds. There are three species of hummingbird commonly found in Alberta: calliope, rufous, and ruby-throated. They all feed on nectar from various flowers, pollinating in the process, and migrate south for the winter.
Introduced: Honeybees
A honeybee foraging on a wild rose. Photo by RJ Pisko, 2016.
You may be noticing one pollinator missing from the above list. The most commonly thought-of pollinator, the honeybee, is not actually on Alberta’s ‘home team’ of native pollinators. They are ‘introduced’, kept as livestock to pollinate crops and to make honey, but they are native to Europe and Asia. Honeybees did not co-evolve with Alberta native plants.
Guests for the Winter
While our largest pollinators (hummingbirds) escape the cold and travel south, most of Alberta’s pollinators hunker down and wait out the winter until flowers are blooming again. Many insects, including most solitary bees, overwinter as larvae. They’ll be inside a custom-built nest that may be found underground, in the stem of a pithy shrub, or in the hollow of a dead tree. Moth caterpillars will spin a cocoon for themselves before winter, then emerge as adults in the spring. Other insects, such as mason bees and bumblebee queens, will spend the winter in their adult stage, burrowed underground or in deep leaf litter.
Overwintering insects depend on protective habitat. If you’re hoping that, come springtime, pollinators will emerge close at hand and pollinate your flowers, you can encourage them to overwinter nearby. Provide multiple options of natural habitat so pollinators have lots to choose from:
Leaf litter: In the fall, leave leaf litter in place so bumblebees and mason bees can burrow underneath. If you can’t or don’t want to leave leaves on your lawn, spread them at the base of trees, shrubs, or flowerbeds. Be sure to leave them undisturbed well into the warmer days of spring, to give the bees time to safely emerge, before raking or mowing.
Stems and stalks: Many solitary bees will use flower or shrub stems as nests, so leave dead flowers and stalks in place, in case baby bees are hibernating in them. In the springtime, if you prune your shrubs or deadhead your flowers, leave the stalks. New growth will hide the stems, but adult bees will find them and make nests, leaving their larvae to stay there over the following winter and emerge the next spring.
Woody debris: Many insects nest and shelter in dead wood. Old logs or stumps, especially with burrowing holes from beetles, are prime habitat for cavity-nesting bees. Another way to provide woody habitat is to build dead branches and twigs into a brush pile, providing lots of sheltered spaces for nesting. You can tuck your pile at the base of a hedge or shrub, or into a corner. To make it prettier, you could also build a brush fence by weaving discarded sticks between stakes.
Alberta’s native pollinators are a fascinating and diverse group of animals, and are important for many of the plants we eat and enjoy. In our backyards, parks, and public spaces, we can all find ways to root for our pollinator home team. Wish our native pollinators luck as they find somewhere cozy to spend the winter, and keep an eye out for them next spring as they emerge!
Funding for OWC’s native range/grasslands projects has been provided in part by:
Habitat Stewardship Program for Species at Risk (Government of Canada)
Rangeland Sustainability Program (Government of Alberta)
Banner image: A bumblebee, tongue out, sipping nectar from a bee balm (Monarda fistulosa) flower. Photo by Annika Wilcox.
