Why has Britain’s wet summer been bad for bees?

This year will be remembered for extremely heavy rainfall in Britain. The intense summer storms resulted in more than double their average rainfall in some places. These wet summers make life even more difficult for bees, which are already battling land-use intensification, chemical exposure, alien species, climate change and habitat destruction.

Wild bees (e.g. bumblebees and solitary bees) have their own annual schedules for keeping, tied tightly to the trees, hedges and flowers on which they feed. Every year in the Northern Hemisphere, around February to March, winter-surviving bees begin to emerge with the warm mornings of early spring, looking for their first food after a long hibernation.

In a typical year, as summer approaches, worker bees will collect nectar and pollen from flowers to feed their queen, who in turn lays eggs that produce more worker bees. Also, the flowers these bees feed on will become more diverse and more abundant. Native bees have evolved to adjust to this natural system. As more flowers become available, more bees form within the hive.

However, the continued growth and expansion of floral resources has suddenly come to a halt due to periods of extended summer rains. This is what scientists are calling “summer collapse.” Simply put, the increasingly wet summer either destroys the flowers on which native bees depend for food or that some bees (such as bees) spend time searching for food that is left in the environment.

Another problem caused by very wet summers is that smaller bees such as bees struggle with flying in the rain but are better able to find small patches of food due to the large number of forest dwellers (about 10,000 per colony). In contrast, bumblebees are better at flying in poor conditions, but struggle to find food when very few due to their comparatively small population (about 25 per colony). Either way, pollinators are lost in a bad summer.

This forage collapse occurs exactly at the point where their colonies are largest. This means there are more bees than ever before, but there is no food for them to eat. And when bees struggle to find food, they are more likely to get sick.

Some plants will try to flower again later in the season (called a “phenological shift”), but by this time, the damage to the bees has already been done. On farm land, bees are maintained by patches of wild flowers and ecological protection areas planted around crops such as woodland and hedgerows. Wet summers are as damaging to wild plants as taking away their flowers.

The pollinators on the farm will not have enough food to sustain themselves before a single mass-flowering event. This occurs when one acre of crops sown at the same time blooms together and requires pollination to produce food. The bees are unable to survive until this happens, which means the farmer’s crop may not be pollinated enough when the time comes.

Read more: Climate change is slowing Atlantic currents that help keep Europe warm

In the coming days, the rainy season is likely to increase. The wet British summer is closely linked to the El Nio/La Nia cycle and the flow of the Gulf Stream. As global ocean and air temperatures rise, the stability of these weather systems has steadily declined. This means that these wet summers are likely to increase in regularity, which has long-term effects on bees.

Making native pollinators more resilient is a major priority, and there are a few things people can do on a smaller scale that add up to make a big difference. Planting more native flowers in the garden will always provide more food, but as mentioned above, bees require frequent feeding.

Plants that are resilient to cold wet periods and can thrive under such adverse conditions are especially important. Ivy, rose bay willow herbs, dandelion, heather and lavender are great in the garden for this reason. Thinking about resilient plants that overlap when they flower throughout the year can help bees cope with humid weather.

Having a constant supply of food is also a major priority for bees, so plants that flower at various points in the summer are helpful: The Royal Horticultural Society has excellent resources for planning a garden according to overlapping flowering times.

Pollination is an important part of the global ecosystem. Food production is dependent on pollination, and pollination is required throughout the life cycle of all flowering plants. Nevertheless, bees are not the only pollinators. Large numbers of hoverflies, small black flies and even bluebottles contribute to plant pollination. These flies (especially hoverflies like the drone fly) require wet areas and stagnant water to reproduce. Wet summers obviously add a lot of puddles and rain, which these animals need to thrive.

The long-term impact of these changing weather systems raises questions that remain unanswered today. Curiously though, more wetter summers can lead to changes in pollinator communities, with greater ecological dependence on hoverflies and other fly species for pollination. This may mean that food production does not suffer, but each time the world loses a species on which it depends for an ecosystem service (such as pollination), these systems become more become fragile and more susceptible to further environmental change.