After a long, busy summer who doesn’t want to cozy up and relax for the winter?
Just like many humans, pollinators use the winter to hibernate and recharge for the upcoming spring and summer. This period of their lifecycle is called dormancy. During dormancy, many pollinator species become inactive and conserve their energy until warmer weather arrives. Pollinators are animals that keep ecosystems in balance by pollinating pants and preying on pests.
Each species has a different survival strategy for the cold, dark winter months.
European honeybees (Apis mellifera) huddle together in a hive to retain warmth. Throughout the year, worker bees collect nectar and pollen to store as honey. Once winter sets in, honeybees actively cluster inside their hives and survive on their honey stores until spring.
Butterflies, like the Western tiger swallowtail (Papilio rutulus), have a very different strategy. In the fall, swallowtail caterpillars find an appealing bit of leaf litter or a brush pile to build a chrysalisA case that a full-grown caterpillar makes around itself to change into a butterfly.; around their body. They remain in this state until the spring when they emerge from their chrysalis as fully formed butterflies. Adult butterflies don’t live more than a year, but they lay eggs during this stage of their lifecycle, helping continue the species.
Other pollinators, like the Rufus hummingbird (Selasphorus rufus), migrate to warmer locations during the cold winter months. These hummingbirds are common summer residents of Pacific Northwest forests and meadows but fly nearly 3,000 miles to their wintering grounds in Mexico!
Bumblebees, like the native, yellow-faced bumblebee (Bombus vosnesenskii), have an annual lifecycle. This means, the entire colony does not survive the winter. In the fall, newly mated queen bees hibernate in ground nests under logs, rocks, or other natural debris. When spring arrives, the queens leave their nests and start new colonies.
Like bumblebees, solitary tunnel-nesting bees, including the blue orchard mason bee (Osmia lignaria) or the leaf-cutting bee (Megachile rotundata), build nests to survive the winter. Solitary bees build their nests in above ground holes or tunnels. The females will lay their eggs within these cavities and seal them with some sort of nesting material until the next season. After laying their eggs the bees will die, but the juvenile bees will emerge in the spring and summer to continue the species.
While each pollinator species has a different winter survival strategy, they can all use some help to make survival just a bit easier.
How to Help:
- Provide winter plant cover! Winter cover offers food and shelter for pollinators, like the Western tiger swallowtail, to stay warm during the winter. Learn more about leaving the leaves.
- Plan your pollinator landscape! Winter is a great time to start planning your garden for next year!
- Put out bird feeders in the late fall, winter, and early spring to provide resident and migrating hummingbirds with food during a time when resources are scarce.
- Build and maintain solitary bee houses. If you’ve provided habitat for tunnel-nesting bees, winter is the time to harvest cocoons and nesting tubes. Winter is also time to clean and store these nesting houses and any unused nesting material.
- Minimize ground disturbance. Whenever possible, limit ground disturbance during the cold months by not walking on or digging in your garden. The bumblebees and butterflies will thank you!