Yes, many species of bumblebee and some solitary bees will hibernate in the ground over winter. They rely on fat stored over the summer months to ensure their survival through to their emergence in early spring.
Winter is a challenging time for bees and with the changeable temperatures, we seem to be experiencing bees are beginning to change their habits.
Let’s take a closer look at why bees hibernate in the ground and why some bees have begun to overwinter without going to the ground.
So why do bees hibernate in the ground?
In the case of most bumblebees, virgin queens produced in the summer will find a male to mate with and then search for an appropriate location to burrow and hibernate.
New queens will generally opt for loose dirt or soil to allow them to dig easily and take advantage of the natural thermal heat created by the earth to keep them warm as temperatures drop.
Large stones, logs, and tree stumps are all optimal locations for queens looking to hibernate.
The shelter provided by these objects helps to reduce the chance she will be disturbed by predators or humans.
Often opting for north-facing burrows, sheltering in the shade ensures the queen is not awoken too early during particularly warm winter days that are getting more regular as the planet warms.
Check out our fascinating read on where bees go in the winter to find out how honeybees, bumblebees and solitary bees behave during the chillier months.
Why are bees choosing not to hibernate now?
Global temperatures have been rising year on year which is forcing bees to change how they approach the winter months.
The buff-tailed bumblebee was noted as one of the first bumblebee species to change its hibernation habits.
This took the form ofbuff-tailed bumblebee queens opting to create nests to overwinter in as opposed to burrowing in the ground.
This strange new habit seems to be fuelled by a mixture of temperature increases and an abundance of winter flowering plants like Heather, Honeysuckle, and Winter Flowering Cherry.
This new form of overwintering has now been adopted by other bumblebee species including the early bumblebee and tree bumblebee, both observed to forgo hibernating in the ground as they have for so many years before.
This has led to bumblebee sightings on warm winter days as they continue to forage for nectar and pollen despite the season.
Which bees hibernate in the ground?
The predominant bee species that hibernates underground is the bumblebee as detailed above.
Furrow bees are an exception among solitary bees which predominantly expire during the start of winter opting to bury their larvae as a method to ensure the species continued survival.
Furrow bees will mate in late autumn with females going to the ground in holes and burrows, finally emerging as spring arrives ready to nest, lay their eggs and raise the young larvae.
Unlike bumblebees that hibernate in the ground, furrow bees will come out to forage from their nests gathering resources for pollen and nectar-rich plants and flowers.
Which bees leave their young in the ground over winter?
Many solitary bees will opt to create holes in the ground or find cavities in wood or masonry to store their larvae over the winter months.
The adult bee will create a waterproof secretion which they use to line the nest ensuring no moisture reaches the nest’s residents.
What to do if you find a hibernating bee in the ground?
Hibernating bees are often found by keen gardeners preparing their soil for summer.
Flower pots, beds, embankments, and anywhere with loose soil can house a hibernating bee just under the surface of the soil.
If you do happen to disturb a bee during this period try your best not to agitate it in any way and return it to its original location as soon as possible.
Make sure you don’t pack any protective soil too tightly, this can make it hard for the bee to dig its way out when it decides to come out of hibernation.
If the bee is particularly active then you can place it in a sheltered area within easy reach of resource-rich flower species.