Climate Change and Beekeeping

The relationship between climate change and beekeeping reaches the beekeeper not as a distant disaster scenario but as a shifting flowering calendar, a longer brood period, drought, heatwaves and weather that is harder to predict. The honey bee is a highly adaptable species, and the main causes of colony losses are still varroa, nutrition and management mistakes; but fixed-date management calendars that used to work are now less reliable. The answer is not to panic but to manage by measuring the colony and the forage rather than following the calendar.

How is climate change affecting beekeeping?

The Mediterranean basin, which includes Türkiye, is one of the regions where warming and summer droughts are felt most clearly. The changes beekeepers see in their apiaries fall under a few headings:

• Calendar shift: Many plants now flower earlier than they used to; late spring frosts, however, still occur.
• Drought: Even when it flowers, a plant under water stress secretes little nectar; the honey flow is shortened or fails altogether.
• Mild winters: The colony rears brood for longer, consumes more stores and varroa produces more generations.
• Extreme weather events: Heatwaves, sudden downpours and floods, storms and forest fires make you rethink the choice of apiary site.
• Spread of pests: The area where some invasive species can survive is expanding; but the main role in moving them is played by human movement of colonies and equipment.

The part that is well supported scientifically is rising temperature and earlier flowering. Their effect on honey yield and colony losses, however, varies from region to region, and research does not yet paint a one-directional picture. That is why the advice on this page is based not on an assumption of "certain disaster" but on flexible management in the face of uncertainty.

Why is the flowering calendar shifting, and can the colony keep up?

The time at which plants flower depends largely on temperature; a mild winter and a spring that warms up early bring almond, plum, willow and fruit trees forward. The colony's spring build-up, however, depends not only on temperature but also on day length, stores, pollen income and the condition of the queen. When the two processes shift at different speeds, a timing mismatch arises: when the main source opens, the colony may not yet have enough foragers.

The point to remember is that about six weeks pass from egg to forager. A beekeeper who wants colonies to go into the main honey flow strong must therefore support their build-up about 6–8 weeks before the source opens. As the opening date of the source shifts, the start of this preparation also has to be read from nature, not from the calendar.

How do drought and heatwaves reduce honey yields?

Nectar is made from the plant's surplus water and sugar. When soil moisture falls, the plant invests first in its own survival; even if it flowers, nectar secretion decreases or stops completely. That is why in dry years the situation of "the field is full of flowers but the hive is empty" is common. In extreme heat the bees also work less in the field at midday and spend part of their energy cooling the hive.

In Türkiye, honeydew honeys are also affected by the climate. Pine honey in the Aegean and Mediterranean depends on the honeydew of the insect Marchalina hellenica, which lives on Turkish red pine; the amount of this honeydew depends on rainfall and humidity and can drop in dry autumns. In summer 2021 the large forest fires in Muğla and Antalya burned a significant part of the pine honey forests; it takes years for burned forest to produce honeydew again.

What to do in periods of drought:

• Monitor weight: Weighing an "indicator hive" every week, or roughly hefting the hive by lifting it from the back, lets you spot starvation early.
• Add boxes according to forage: Putting on unnecessary boxes before the flow arrives increases the volume the colony has to heat and defend.
• Watch out for robbing: When the nectar stops, robbing increases quickly; reduce entrances, keep inspections short and don't spill syrup.
• Feed if necessary: Leaving a colony hungry through a long dearth means going into winter with a weak colony in autumn.

Heat stress: hive temperature and water needs

Bees keep the brood nest at about 34–35 °C whatever the outside weather. In a heatwave they manage this by fanning their wings to create an air current and by evaporating the water they bring in. That is why the number of water-carrying bees increases in hot weather, and the colony struggles if there is no clean water nearby.

• Water source: Keep a permanent waterer near the apiary, with stones or floating material so bees can land without drowning.
• Shade: In hot regions, tree shade that cuts out the afternoon sun, a light-coloured roof on the hive and an air gap between the roof and the hive make a difference.
• Ventilation: Provide an adequate entrance width and, if necessary, a mesh floor or an upper ventilation gap; give crowded colonies room in good time.
• Inspection time: During a heatwave don't open hives in the midday heat; newly drawn comb goes soft and can break off when the frame is lifted.

What do mild winters mean for varroa and winter stores?

In mild autumns and winters the queen stops laying later and starts earlier; in some coastal regions the colony is almost never without brood. This has two important consequences:

1. Varroa produces more generations. The mite reproduces only in capped brood; the longer the brood period, the larger the mite population grows.
2. The broodless period narrows. In winter, treatments such as oxalic acid that affect only the mites on adult bees are most effective during the broodless period. As the broodless window becomes less predictable, the treatment date has to be set not by the calendar but by looking at the brood status in the hive.

The second effect of a mild winter is consumption of stores. A colony that stays more active and starts brood early consumes more honey than in a cold winter. Winter stores that used to be considered sufficient may not last to the end of a mild winter. Hefting the hive in midwinter and early spring prevents starvation that is noticed too late.

New pests and diseases: climate or transport?

Warming expands the area where some invasive species can survive. But the main factor in these species reaching new regions is usually transport by human hands: the trade in colonies, queens, package bees, used comb and equipment. Climate opens the door a crack; transport carries them in.

• Tropilaelaps mite: This mite of Asian origin was confirmed in colonies in southern Russia and Georgia in 2024; in other words, it has reached Türkiye's north-eastern neighbours. It is smaller than varroa, moves fast and does severe damage to brood.
• Small hive beetle (Aethina tumida): Breeds more easily in warm, humid conditions; in Europe it has been found in southern Italy.
• Hornets: The oriental hornet (Vespa orientalis), native to southern Türkiye, can put serious pressure on hive entrances in hot summers and autumns; in Europe, the yellow-legged (Asian) hornet (Vespa velutina) has spread rapidly.

Tropilaelaps and the small hive beetle are notifiable agents. If you suspect them, do not start treatment on your own; without moving the colony or the frames, notify the official veterinary service / local agriculture authority.

Apiary siting against floods, storms and forest fires

As extreme weather events become more frequent, the risk calculation in choosing an apiary site changes too:

• Stay away from stream beds and hollows: Dry stream beds can turn into flood channels within hours in a sudden downpour.
• Secure the hives: In windy spots, strap the hives to their stands or put a weight on the roof.
• Leave a firebreak: In woodland, clear the dry grass around the hives; be extra careful when using the smoker on windy, dry days.
• Insurance: In Türkiye, hives can be insured under the state-subsidised agricultural insurance scheme (TARSİM); read the policy to see which risks are covered.

How can beekeepers adapt to climate change?

The essence of adaptation is moving from the approach of "every year you do this on this date" to "you do what the hive and the forage tell you". The table below summarises the main changes and their practical responses:

Other steps that pay off in the long term:

• Local bee races and ecotypes: Local bees that have adapted to the region's conditions over centuries are often hardier than lines brought in from distant regions.
• Diversity of forage: Places with plants that flower at different times are less vulnerable to drought and frost than places dependent on a single source. If possible, support late-summer and autumn forage.
• Keeping records: A beekeeper who writes down flowering, honey flows, varroa counts and winter losses year by year can see change in their own apiary and make decisions accordingly.
• Spreading apiaries out: Setting up apiaries at several different altitudes and aspects instead of keeping all colonies in one spot prevents a single flood, fire or dearth from hitting the whole operation.