The year 2024 has officially been declared “the worst year for bumblebees since records began” by the Bumblebee Conservation Trust. While out in the field surveying pollinators across southern England, GWCT researchers also noticed a shocking decline in bee numbers compared to previous years. And they were not alone — 100% of respondents in an Instagram poll (@farmlandecologygwct) reported seeing fewer bees than usual.
What’s behind these declines? The dramatic drop of these crucial pollinators in 2024 could be driven by climate change.
The climate crisis and our insects
Extreme weather is increasingly disrupting ecosystems, and insects are no exception. Research from GWCT (Ewald et al. 2015) found that many invertebrate groups decline in cold, wet years and struggle to recover when weather patterns shift unpredictably. Winters in the UK have become milder, but that doesn’t necessarily mean good news for bees either.
Red-tailed bumblebees particularly suffered from the conditions of 2024. In 2024 GWCT researchers recorded only 30% of the red-tail workers seen across the same sampling areas in 2019. These observations reflect national trends reported across England. In early spring, queen bumblebees are on their own, working tirelessly to forage, build a nest and establish a new colony of workers. Fewer worker bumblebees are indicative of wet springs and unreliable summer weather impacting the queen bumblebees’ survival and her ability to forage while she establishes a colony.
As one of the ‘Big 8’ common UK bumblebees, this charismatic and distinctive species should be among the most common bumblebees we see during summer. Fewer red-tailed bumblebees are a symptom of much larger issue for pollinators. Unreliable, cooler and wetter summers reduce bees’ ability to gather nectar, limiting food for both adult bees and their developing colonies. In 2024, the UK experienced its warmest spring on record by a whole 1°C. This period was also wettest since 1986 and the sixth wettest on record, with 32% more than the seasonal norm.
Mild winters also confuse seasonal cues for bees and other wildlife, causing hibernating species to emerge too early. When warm spells in January or February trigger early activity, sudden frosts can be fatal. Hardy species such as buff-tails (Bombus terrestris) are even attempting second broods during winter. However, bee activity is meant to align with peak flowering times, providing reliable food supplies. Not so easy to find in January.
The period from October 2023 to March 2024 was also the wettest on record for England and Wales, with flooding that was devastating for many farmers. This exceptionally wet winter likely had severe consequences for ground-nesting bees, particularly red-tail bumblebee queens, which overwinter underground. Prolonged flooding can be fatal for these queens, drowning them before they can emerge in spring to establish new colonies. Male and female mining bees also face similar risks as heavy rain saturates the soil. Even species that can withstand short periods of waterlogging struggle when extreme rainfall continues into spring. Additionally, widespread flooding may degrade pollinators’ foraging habitats, disrupting the establishment of flowering plants in natural and semi-natural areas.
Other pressures on pollinators
These trends aren’t just affecting bees. The Sussex Study (Ewald et al. 2024) found a 37% decline in invertebrate abundance in cereal crops since 1970, with some key beneficial groups like ground beetles and ladybirds dropping by over 75%. Similar declines have been seen in butterflies, moths and other pollinators.
Climate change is definitely a factor, but it’s only part of the problem. Habitat loss, pesticide use, and even increased predators all contribute to the growing crisis facing our pollinators. To fully understand invertebrate declines, we must also consider the other pressures driving these trends.
Diverse landscapes are critical for pollinators’ food and nesting sites, but habitat loss and fragmentation is driving wildlife decline and limiting species’ ability to recover from population crashes. Sprawling human infrastructure, land-use change, and historical agricultural intensification has reduced insects’ habitats with only 3% of the UK’s wildflower-rich meadows remaining compared to the 1930s. Infrastructure, poor hedge quality and ecological deserts of single crop, plant or tree species further isolate populations. This makes it difficult for species to move between suitable habitat, reducing genetic diversity and hindering long-term survival.
Research has consistently shown that pesticides harm bee health, reducing foraging and navigation ability as well as weakening colony health. Even herbicides, which aren’t designed to be directly toxic to insects, remove vital wildflowers from the landscape and accumulate in the bodies of the plant-feeding insects, which still lead to reduced insect health. This issue extends beyond farmland to domestic gardens. Gardens can provide a huge resource of flowering plants for pollinators and other beneficial insects, but even chemicals used in gardens will have negative impacts on the very insects we need to help and protect.
Disturbance by predators, parasites and human activity also contributes to pollinator mortality, though its impact on overall population levels remains uncertain. A 2017 study by Goulson et al. found that badgers were responsible for 50% of observed bumblebee nest failures, while human disturbance accounted for 26%. Wax moth infestations and even ants also diminish the health of bee colonies. However, more research is needed to fully understand if increases in human and other wildlife disturbance is directly limiting bee populations or if they are compensated for by other ecological processes. Understanding these dynamics is crucial for assessing pollinators’ ability to recover from multiple threats throughout their life cycle.
Challenges for farmers
It’s not just insects struggling with the changing climate; farmers are also facing new challenges. Prolonged wet weather in 2024 flooded fields, delayed planting schedules, and damaged crops. While pollinators are vital for many agricultural systems, the pressure to maintain productivity sometimes leads to intensive management strategies that can harm biodiversity.
By making small changes, however, farmers can help bees while also improving soil health, reducing runoff, and supporting overall ecosystem stability.
What can be done?
For farmers:
- Flower margins and habitat management: Leaving cultivated margins undisturbed increases flower abundance and benefits pollinators. Sowing floristically enhanced margins also boosts flowerhead availability.
- Reduce pesticide use: GWCT research has also found that using half the usual dose of insecticides can still effectively control pests while reducing harm to beneficial insects.
- Encourage natural vegetation: Minimising herbicide use and removing cuttings to lower soil fertility allows native species to establish naturally, fostering a more resilient pollinator population. Sowing native flower seeds is also a great way to also boost the success of floristically enhanced margins.
- Hedgerow and field boundaries: Hedgerows provide essential shelter and floral food resources for a range of wildlife. Maintaining hedgerows and cutting them on rotation every three years is recommended to balance necessary management while still ensuring flowers have to opportunity to grow.
- Soil health and flood mitigation: Cover cropping, reduced tillage, and uncut margins can all help manage water flow, improving both farm productivity and habitat for insects.
For more management advice visit the GWCT Guide to Insect Rich Farmland Habitats and for more information on native seed mixes visit GWCT Partridge Project Mixes from Oakbank Game & Conservation.
For everyone:
- Plant bee-friendly flowers like clover, thistles, ivy and bird’s foot trefoil. Native plants provide the best food sources. Focus on providing a range of different floral structures – big open ones, bell-shaped ones, tiny ones.
- Leave bare patches of earth for ground-nesting bees. Avoid artificial ground sheeting that prevents burrowing.
- Reduce pesticide use, especially insecticides and herbicides that harm pollinators.
- Install and maintain bee hotels to provide nesting sites for solitary bees. Bring them into a shed over winter to protect emerging bees.
- Leave areas of uncut grass and plants for bees to nest in.
For more information on bee hotels for adults click here, and you can make your own for kids.
Looking forward
The decline in pollinators is a worrying trend, but it’s not too late to take action. By making informed choices, whether in our back gardens or across agricultural landscapes, we can create a future where bees and other beneficial insects continue to thrive.
With climate change bringing more uncertainty each year, supporting pollinators is more important than ever. Small changes add up, and by working together, we can help safeguard the biodiversity that sustains our ecosystems, food production, and natural landscapes.
Reading list
- More advice on flower seed mixes for pollinators:
Research papers
- McHugh, N., Bown, B., McVeigh, A., Powell, R., Swan, E., Szczur, J., Wilson, P., & Holland, J. (2022) The value of two agri-environement scheme habitats for pollinators: Annual cultivated margins for arable plants and floristically enhanced grass margins. Agriculture, Ecosystems & Environement, 326: 107773.
- Ewald, J. A., Potts, G.R., Aebischer, N.J., Moreby, S.J., Wheatley, C.J., Burrel, R.A., (2024) Fifty years of monitoring changes in the abundance of invertebrates in the cereal ecosystem of the Sussex Downs, England. Insect Conservation and Diversity, 17: 758-787.
- Stoate, C., Leake, A.R., Jarvis, P.E., Szczur, J., & Moreby, S.J. (2015) The Allerton Project: twenty-three years of agricultural and environmental data collection on a commercial farm. Aspects of Applied Biology, 128: 27-33.
- Ewald, J.A., Wheatley, C.J., Aebischer, N.J., Moreby, S.J., Duffeild, S.J., Crick, H.Q.P., Morecroft, M.B. (2015) Influences of extreme weather, climate and pest on invertebrates in cereal fields over 42 years. Global Change Biology, 21: 3931–3950.
- D. Goulson, S. O'Connor, K. J. Park, (2017) Causes of colony mortality in bumblebees. Animal Conservation, 21: 45-32.