How Drought, Warm Winters, and Extreme Changes Are Threatening Bees and Beekeeping in Bulgaria
Key Points:
- Winter losses of bee colonies in some regions reach up to 70% — in Pleven and even 100% in Ruse, mainly due to “starvation death” and a confused winter cycle.
- The drought in 2025 — one of the most severe — reduces the food base for bees and leads to weaker honey yields.
- Between 600 and 800 species of wild bees in Bulgaria are losing their habitats and food sources.
- The mismatch between plant flowering and pollinator activity threatens entire species.
- Beekeepers face lower yields, diseases, and uncertainty in the craft, though some manage to adapt with traditional methods against heatwaves.
The climate has always influenced bees and plants, but in recent years the changes have become increasingly palpable and unpredictable. Unusually warm winters, followed by drought and hot summers, are testing both wild and honey bees — of which there are between 600 and 800 species in our territory. Increasingly frequent extreme events, combined with diseases, pesticides, lack of food, and improper care lead to alarmingly high mortality. As a result, entire bee colonies are threatened, and with them — a large part of the plants dependent on bee pollination. Losses just last winter in some areas are approximately 70%. What do beekeepers and agronomists share from their personal experience about these changes and alarming trends? Is there anything we can do?
Severe Drought and Heatwaves: The Summer That Deprived Bees of Food
In 2025, the sharp drought became one of the main reasons for the reduction of food for bees. According to data from the National Institute of Meteorology and Hydrology, this summer was one of the driest since the mid-20th century. This placed Bulgaria in the ranking among the 10 countries in Europe most affected by forest fires (according to the European Forest Fire Information System).
In addition to the reduction of food resources, high temperatures caused concerns in the beekeeping sector. During the summer months, with rising temperatures, beekeepers raised alarms about weaker honey yields. The reason is the reduced nectar secretion from plants, which also weakens the bee colonies. This reduces their chances of survival through the winter.
Although this year no mass damage to hives from fires was observed, in some areas there are cases of burnt or damaged apiaries.
With rising temperatures, wild bees suffer great habitat losses. While honey bees are cared for by beekeepers, wild bees must adapt to the changing environment on their own. As a result of increased temperatures, the places suitable for their habitation and reproduction are decreasing.
Warm Winters and Starvation Death: When Nature Confuses the Bees
Proper overwintering of bees is extremely important for their survival through the winter. This year, however — as a result of the constant temperature fluctuations during the winter season — most beekeepers failed to prevent the high mortality of honey bees. In the Pleven region, losses reach 70%, and in the Ruse region — even up to 100%. Among the main reasons are the so-called starvation death due to insufficient food reserves in the hives, as well as the warm winter, which tricks pollinators into searching for flowering plants when in practice such are lacking. Unlike honey bees/species, the generation of ground-nesting bees this winter suffered significantly less than usual.
Climate Stress and Diseases in the Hive
According to agronomist Roman Rachkov, the thermal stress in honey bees, caused by rising temperatures, leads to a weakening of their immune defense. This facilitates the development of infections in the hive, which, if not controlled in time, can threaten a large part of the bee colonies. A similar effect is observed in some species of wild bees. The main difference is that honey bees are partially heterothermic: through the collective activity of the colony, they can control the temperature in the hive, while wild bees are ectothermic and depend to a greater extent on external heat sources to regulate their body temperature. Bumblebees are among the wild bee species where this phenomenon has been proven — exposing them to thermal stress reduces their ability to pollinate and reproduce.
The Fragile Balance That is Crumbling
Rising temperatures cause earlier or later flowering of some plant species, just when bees are in winter dormancy or have not yet reached their peak activity. The phenological mismatch affects both honey bees and wild bees, but the effect is significantly greater in wild bees, as they are not assisted by beekeepers. This mismatch can lead to the endangerment or even extinction of some species.
A Beautiful Spring Flower and Its Sole Bee
The Pasqueflower (Pulsatilla vulgaris) is a beautiful, early spring wildflower from the Buttercup family. It is pollinated only by one species of wild bee (Osmia bicolor). When — due to climate changes, there is a mismatch in the period of the bee’s emergence and the flowering, the pollination of the pasqueflower cannot occur. Thus, the plant’s population is already threatened with extinction. In some countries, the flower is included in the red lists of endangered species because its habitats are disappearing and its pollinators are decreasing.
The Voice of the Beekeepers: A Profession on the Brink of Survival
Climate changes, among other factors, present Bulgarian beekeepers with a dilemma: whether to continue with their craft or seek another alternative for livelihood. Although this year the State Fund “Agriculture” supports beekeepers by paying out nearly 6 million leva to applicants, interest in beekeeping still remains low. Forecasts for this year are that the utilized funds will be about 5%.
In the sector, there remain beekeepers who continue to enjoy the profession, facing a number of challenges. One of them is Krasimir Kostov from the village of Ezerets, Shabla region, who for over 25 years has been caring for 150 hives in his main apiary and another 11 — in a smaller one. His trademark expression is, “When you love bees — you become a beekeeper not once, but several times.”
The change in climate that Krasimir Kostov notices is expressed in the unseasonably cold spring. Last April, it snowed twice, accompanied by so-called frost, which led to the freezing of fruit trees and vegetation. This also affected the bees. Strong bee colonies react more favorably to climate changes, while weaker ones are significantly more vulnerable. The constant alternation of warm and cold periods during the winter also had a negative impact.
“During the cold spring, there was a large number of lost colonies, and during the winter — also high mortality. For some colonies, it proved problematic, but there were beekeepers who did not have these difficulties.” Krasimir Kostov.
The beekeeper explains that the hot summer is the reason for less nectar secretion from plants. Flowering vegetation is not lacking, but high temperatures limit the time during which plants give nectar, and this inevitably affects the honey yield. With a shorter period for nectar collection, the strong bee colonies react first, managing to gather part of the necessary reserves, Kostov adds.
On the Natural Defenses and Adaptation of Bees
Bees exhibit natural protection against thermal stress. They stay in the hive or remain sheltered and do not collect honey and pollen when it is too hot or there is no nectar. If there is flowering vegetation during hot periods, they go out only for one to two hours. When there is no nectar or pollen, they fly out only with a specific purpose, such as orientation flights for young bees or to cleanse their bodies.
Bees are created to adapt to temperature changes. Even with sudden cold snaps or warm spells, the structure of the hive, with one queen bee and tens of thousands of workers, allows for quick and effective response to natural amplitudes, Kostov adds.
This type of organization in their colonies gives bees the opportunity, for a short period of about ten days or two weeks, to accumulate food reserves that ensure their survival for a longer period. Bees nest and collect pollen in order to compensate for fluctuations in the environment.
For beekeepers, this adaptation mechanism also creates problems. The natural amplitudes and short periods for nectar collection can lead to lower honey yields. This affects both the beekeepers and the bees.
Last year, the Shabla beekeeper lost about 50% of his bee colonies. This year, however, his bees are in good condition. He believes the climate also affects the two main bee diseases — varroosis and nosemosis. And yet, the main factor for the survival and good condition of bee colonies remains proper selection and care for their health.
The beekeeper confirms: climate changes have an impact on the craft. In Northern Dobrudzha, honey yields have decreased, and the lower production makes it difficult for beekeepers to plan their budget, making the profession more uncertain. He also notes a trend towards the enlargement of apiaries and the decline of smaller ones. Large producers, who are professionally engaged in beekeeping, manage to achieve good yields. Some compensate for the short nectar secretion period through migratory beekeeping, moving part of the hives to another location to extend the season. However, this requires good organization.
“In all cases, the honey yield in Northern Dobrudzha has decreased. Naturally, this calls into question the profitability of the profession,” believes Kostov.
Small Steps with Great Significance for Pollinators
Climate changes have a great influence on the pollination, reproduction, and survival of these pollinators so important to us. But the question is what we, humans, can do to deal with this serious problem for biodiversity.
The Old Tricks with Which Bees Survive Heatwaves
Krasimir Kostov uses several old-fashioned but effective approaches to protect his bees from the heat. One of them is painting the hives white against the bright sun, thus reducing their overheating. Another method is widening the hive floors and enlarging the entrances to allow more air to enter. In extreme cases, the beekeeper places a mesh instead of boards to provide additional ventilation.
Beekeeper Kostov never forgets to provide his bees with access to fresh water. Some of his tricks include placing hives near trees providing light shade, as well as in places with airflow. He recommends green, well-mowed ground around the hives, which helps cool the bee colonies.
Seed bombs – small balls with great power
A fun, easy and effective way to help nature are the so-called. Seed bombs – small balls of soil and native seeds that can be thrown in the garden, in meadows or in urban spaces. They contain a mixture of wildflowers suitable for both honey and wild bees. Some non-governmental organizations in our country are already offering similar bombs and actions that allow each of us to support pollinators with small but real actions – see, for example, the “Grow the rainbow” campaign.
Conclusion: Bees are among the most sensitive indicators of climate change — their loss is a warning of deep processes in nature. Bulgarian beekeepers are already feeling the consequences. With care, adaptation, and support, we can preserve not only beekeeping but also the balance in ecosystems. Protecting pollinators is not just a professional cause but a matter of shared responsibility for the future.
Header photo Ecovarna.info, free use
The authors of the publication are Yoanna Ivanova and Roman Rachkov. The article was created within the framework of the Climatic Laboratory, initiated by the Association of European Journalists and Klimateka.