Overcrowding with bees: is Poland already running too many hives?

Let us start with a number that gives pause. There are about 2.4 million bee colonies in Poland. As many as in the United States, a country more than thirty times larger than us. That one sentence says more about Polish beekeeping than many a report: on our modest territory a gigantic number of hives is crammed together. And this text is exactly about that, because since the Polish Beekeeping Association is putting the topic of overcrowding on the table, it is worth looking at it coolly, with hard data and science in hand, not on emotion.

I will say at once, to avoid misunderstanding: this is not a text about the honey bee destroying nature, nor about you having to wind up your apiary. It is a look at a real problem that strikes two sides at once: wild pollinators and, which beekeepers often overlook, the beekeeper's own pocket.

What overcrowding is and how much of it we have

Overcrowding, in technical terms bee density (napszczelenie), is simply the number of bee colonies per square kilometre. The more of them, the more mouths to feed from the same, limited forage base. And here the hard numbers begin.

According to data from the Institute of Horticulture in Puławy, the average bee density in Poland is about 7.7 colonies per square kilometre. But the average lies, because the spread is enormous. In the south of the country, in the Małopolska macroregion, it reaches 12.5, and in Małopolska itself it climbs to almost 14 colonies per kilometre. At the other pole is Mazowsze with about 4.9, that is over two and a half times less. In other words, we have in Poland regions crowded to the limit and ones where there is still plenty of room.

Why does this matter? Because there is such a thing as the forage carrying capacity of an area, that is the number of colonies a given locality can feed without a drop in yield. Polish work, among others by Professor Jerzy Wilde, indicates that good honey yields are possible where accumulation does not exceed roughly seven colonies per square kilometre. Set that against the real density of southern Poland and you will see that in many places we crossed that threshold long ago. This is not an abstraction, but a ceiling that a particular beekeeper hits at a particular harvest.

What overcrowding does to your apiary

Before we get to wild pollinators, which are talked about most, let us start with something that should move a beekeeper more: their own yields and colony health. Because overcrowding is not an ecologists' problem, it is a problem for your wallet.

The first thing is competition for forage among the honey bees themselves. When too many hives stand on the same ground, colonies take nectar and pollen from one another, and the effect is simple: less honey per colony. Henry and Rodet's research even showed that intensified competition within the species is a signal that the local carrying capacity has been exceeded, which hits both yields and colony condition. Your bees fight over the same flower with the neighbour's bees, and both sides lose.

The second thing, more serious, is disease. The denser the hives stand, the more easily pathogens jump from apiary to apiary. Bees drifting between hives, the robbing of weakened colonies, shared flows where bees from different apiaries meet, all of it is a motorway for varroa, foulbrood, nosema and viruses. In crowded terrain one neglected, collapsing colony becomes a varroa and disease bomb for everyone within flight range. I wrote about this under robbing and varroa, and overcrowding is a phenomenon that cranks this whole mechanism up to the maximum. You cannot run a healthy apiary in isolation from what is happening at your neighbours', if the neighbours are many and stand close.

The third thing is pollen and protein scarcity. Too small a base of forage plants for too many colonies means the bees lack not only nectar but pollen, and without pollen there is no good fat body and no good winter bee. Overcrowding can therefore indirectly worsen wintering, because colonies enter winter less well nourished. This ties in with what I wrote about the fat body: a pollen shortage in late summer is the quiet cause of weak winter generations, and in crowded terrain that shortage comes far more easily.

When forage runs short: forced feeding and pseudo-honeys

There is one more, very practical effect of overcrowding, seen in apiaries more clearly year by year: the compulsion to feed not only for winter, but mid-season, so the colonies can function properly at all. The classic moment is the period after the lime flow, when the big flows end and in crowded terrain what remains does not suffice for everyone. Then many apiaries have to give syrup, so the colonies do not weaken, do not cut back brood and go into the next flow in form. The denser the hives, the more often and earlier you have to reach for the feeder, because the natural base simply cannot keep up feeding so many colonies.

And here begins ground on which it is easy to slide. But the line has to be drawn in the right place, because a mental shortcut is tempting. An addition to honey, juice or herb, is not itself a sin. I, for instance, make honey with raspberry juice and honey with nettle juice for my family, and I consider it fine, because the base is real honey, not sugar. I do not sell such a product, because with a honey base the price would be prohibitive, and topping up a decoction with sugar to make it cheaper simply does not sit with my conscience. And that is the crux: the problem is not that something was added to the honey, but what it is replaced with.

Because the slide begins where, in crowded, forageless terrain, an apiary, instead of waiting for nectar, switches to producing so-called herb-honeys on sugar. The mechanism is the same as with my homemade one, only the carrier is different: the beekeeper prepares a thick sugar syrup with an addition of juice or decoction, say raspberry or nettle, pours it into the feeders and puts it in the hives. The bees, lured by the smell and taste, treat it like a flow, take it, thicken it to honey consistency and cap it, and the beekeeper then extracts the finished product and sells it, often dearer than real honey. The plant on the label, like raspberry or nettle, either does not secrete nectar in nature or the bees ignore it, so a bee would never gather honey from it on its own. All the sweetness here comes from sugar, not from a flow.

And this has to be said plainly: such a sugar product, in the light of the law and the honey norm, is not honey, because honey arises from nectar or honeydew gathered by bees, not from syrup handed to them by a human. Polish law has moreover not regulated herb-honeys separately, so they circulate in a grey zone of naming, and a misleading name with the word honey and a price higher than honey can mislead the consumer. And to be fully honest: my homemade honey with juice, though it stands on a honey base, is also no longer honey in the full sense of the norm, because honey by definition may have no additions. It is a honey-based product, not pure nectar honey, and that is what it would have to be called if it ever went on sale. The difference from the sugar pseudo-honey is nevertheless fundamental: with me the sweetness still comes from real honey, and there from sugar posing as a flow, and it is that product that is sold as honey, which it is not.

What the science says about wild pollinators

Now the other side, the one the media trumpet, that is the honey bee's effect on wild pollinators. And here one has to be honest and precise, because the topic is hot and it is easy to overstate in either direction.

The scientific facts are these. The honey bee is a powerful food competitor, because it is a floral generalist, occurs in huge numbers, has a fine sense of smell and scouting ability, stores food and winters as a whole colony. Cane and Tepedino point out that one colony can gather in a season an enormous mass of nectar and pollen, which are then lacking for wild insects. Torné-Noguera and colleagues showed that competition can be detected already at a density of around three and a half colonies per square kilometre, well below the Polish average. Valido and colleagues showed that at high honey bee density the number of flower visits by wild pollinators falls. Henry and Rodet in turn calculated that competition effects reach from six hundred to eleven hundred metres around an apiary, and proposed that instead of density limits it would be better to regulate minimum distances between apiaries.

But, and this is important, the science is not unanimous here and does not paint a simple picture of doom. The large review by Mallinger and colleagues from 2017, covering dozens of studies, showed that yes, overlap of the food base is common, but real negative effects on wild bees are context-dependent and do not always appear. There are studies, including from semi-natural areas, where the honey bee's presence could not be linked to harm to wild pollinators. The key turns out to be the landscape and the amount of natural habitat: where flowers are plentiful, species can coexist, and where the base is poor, competition sharpens. In other words, the problem is rarely the mere presence of hives, and more often the combination of density with a poor forage base.

An honest view: the beekeeper is both victim and perpetrator

From this emerges a picture less striking than the media headlines, but truer. Overcrowding is not a matter of the bad honey bee versus poor wild insects. It is a matter of balance between the number of hives and what the area can feed. And in that balance the beekeeper stands on both sides at once.

They are a victim, because in crowded terrain they harvest less honey per colony, have a harder fight with disease and weaker colonies. They are a perpetrator, because by forcing hives in where it is already dense, they deepen the problem for themselves, the neighbours and the wild pollinators. It is uncomfortable but important, because it shows the solution lies not in blaming anyone, but in reasonable management of space. And that the beekeeper's interest, that is good yields and healthy colonies, largely overlaps with nature's interest, that is room for wild pollinators. It rarely works out that way, and here it happens to.

It is also worth adding the economic context, because without it the topic hangs in a vacuum. Polish beekeeping faces a flood of cheap imported honey, low purchase prices and rising costs. Bee density and falling yields per colony add to this pressure, because from overcrowded terrain it is harder to squeeze profitability. After years of growth the number of beekeepers and colonies in Poland has fallen slightly for the first time, which some read precisely as a signal that the sector has hit the wall of capacity and profitability at once.

Migratory apiaries: a cuckoo's egg for the stationary ones

A separate, touchy thread is migratory apiaries. Moving bees to flows, to oilseed rape, buckwheat, lime or heather, is a normal and often necessary tool of professional beekeeping, because with rising costs varietal honey from migration is sometimes the only route to profitability. There is no point demonising it. The problem begins when a migratory apiary lands in terrain that is already crowded, or on a flow where local bees are already working.

Because a flow is like a cake: only a set number of slices can be cut from it. Bringing dozens or hundreds of hives to flowering rape, next to which local apiaries already stand, does not make more nectar. It only makes more mouths to divide it among. For a stationary apiary such a sudden visit can be a cuckoo's egg: overnight its bees have to share the flow with thousands of strangers, and yields can then slump for everyone at once.

On top of this comes a second, more serious matter: disease. A migratory apiary is bees from a completely different region, with their own baggage of varroa, foulbrood, nosema and viruses, set suddenly in the middle of a local population. Shared flows, drifting and robbing do the rest. One irresponsible migratory beekeeper who brings sick, varroa-ridden colonies to a flow can gift the whole neighbourhood a problem that stays long after he packs up his hives and drives off.

The point is not to ban migration, because it is an important part of the trade. The point is ethics and coordination: not forcing your way in where the flow is already taken, coming to an understanding with the locals, keeping the moved colonies healthy and not turning someone else's pasture into a buffet for your own neglected hives. In crowded Poland, where migratory apiaries are multiplying, this is an increasingly common source of real conflict between beekeepers.

How to assess whether your terrain is overcrowded

Instead of guessing, you can count it, and with simple tools. Start by drawing a circle of a one-and-a-half to two kilometre radius around the apiary, even on a free online map. This is your real bee pasture, an area of the order of seven to twelve square kilometres, from which the colonies gather profitably. A bee will fly further, since the flight range reaches even five kilometres, but it will then spend on the journey almost as much as it brings, so for the forage account it does not count.

Then look at what grows and flowers in that circle through the whole season, and how many hives already stand in it, counting the neighbours too. A simple reference point: it is taken that the terrain feeds, without a drop in yield, roughly six to seven colonies per square kilometre. Multiply the pasture area by this figure, subtract a reserve for leaner years and for competition with wild pollinators, estimated at up to thirty percent of the available forage, and you have a rough number of colonies the terrain will bear. You will count it more precisely by summing the honey yield of the plants in range, given in kilograms per hectare, but even a rough sum with the radius and the figure of seven colonies per kilometre will tell you a lot.

It is worth keeping in mind one more principle that orders the thinking: a colony first eats a good part of the gathered forage for its own needs, for rearing brood, wax and survival, and only the surplus above that goes to your honey house. As an orientation point it is taken that a colony uses on itself of the order of eighty to a hundred kilograms of forage a year, but I stress this hard, because it is only an average. In reality it depends on race, climate, season length and colony strength and can vary a good deal, so treat this number as indicative, not holy. More important than the figure itself is the mechanism: every added hive must first feed itself from the same, limited pool before it gives anything to you. That is why adding colonies to crowded terrain so quickly stops paying off.

What to do about it in practice

Since the problem is real, what can a single beekeeper do, without waiting for top-down regulation?

First and foremost: do not force hives into crowded terrain. Before you set up an apiary or expand it, look around at how many hives already stand within flight range. If the area is crowded, adding more colonies will not give you more honey, only dilute the yields for everyone, yourself included.

Second: space your apiaries with sense. A bee flies far for forage, even some five kilometres, but a truly profitable flight, on which it brings more than it uses, is only about one and a half to two kilometres from the hive. That means two apiaries a kilometre, even two, apart in practice gather from the same flow, because their flight fields largely overlap. To really limit competition, the distance between apiaries should run into several kilometres. A few smaller apiaries properly scattered across the terrain will gather better than everything brought into one place or set too close together.

Third: care for the forage base. It is the only way to really raise the capacity of the terrain, rather than just dividing the same pool among more hives. Sowing field margins and wasteland with pollen and nectar plants, planting willows, limes, fruit trees and honey shrubs, catch-crop sowings, all of it raises the ceiling you are hitting. I wrote about specific plants under the fat body, and it is no accident that the same actions help both against overcrowding and towards a good winter bee.

Fourth: read your own yields as a signal. If year on year you gather less per colony despite good management and weather, that may be precisely a signal of exceeding the terrain's capacity. A drop in yield per colony is the thermometer of overcrowding, and it is worth watching.

Curiosities and controversies

We have as many colonies as the USA, being thirty times smaller. This one number conveys the scale of the phenomenon better than any chart. About 2.4 million colonies in Poland is a level comparable with the United States, despite the gulf in area. It does not automatically mean catastrophe, because distribution and forage base matter, but it shows how tight it can get on the Polish flow.

First the colony feeds itself, only the rest is your honey. A good part of the gathered forage, orientationally of the order of eighty to a hundred kilograms a year, though this is only an average dependent on race, climate and season, the colony uses for its own needs, for brood, wax and survival. Only the surplus above that goes to the honey house. The principle itself sets the thinking about overcrowding: every added hive first feeds itself from the same, limited pool before anything is left for you.

Regulate distance, not density. The classic idea is a limit of colonies per square kilometre, but Henry and Rodet argue that setting minimum distances between apiaries is more practical. It is easier to enforce and better reflects reality, because competition radiates around each apiary, not evenly over a square of the map.

It is not a simple story of the honey bee's guilt. Contrary to some headlines, the science does not confirm that the honey bee always and everywhere harms the wild ones. Mallinger's review showed the effects are context-dependent, and mainly the landscape and forage base decide. Where flowers are plentiful, species coexist. It is an important safeguard against tipping into extremes in either direction.

Two myths

Myth one: the more hives, the more honey. Below the terrain's capacity yes, but above it the opposite is true. Adding colonies to crowded terrain lowers the yield from each colony, so more hives then give less honey per colony, not more. What counts is not the number of hives, but how much forage falls to each colony.

Myth two: the honey bee destroys wild pollinators, full stop. It is a mental shortcut the science does not confirm in such a simple form. Competition can be real, especially at high density and a poor base, but in a landscape rich in flowers species can coexist. The enemy is not called the honey bee, but overcrowding combined with a forage desert.

Most common mistakes

Adding hives to dense terrain. Expanding the apiary where it is already crowded dilutes the yields for everyone, yourself included. First check how many hives stand within flight range.

Bringing everything into one place. A large apiary in one spot competes with itself. A few smaller ones, spaced several hundred metres to a kilometre apart, gather better.

Treating a yield drop as bad luck. A falling yield per colony despite good management is often a signal of exceeding the terrain's capacity, not a whim of the weather.

Ignoring the forage base. Without sowing and planting honey plants you only divide the same pool of forage among ever more hives. Raising the terrain's capacity is the only real way out of overcrowding.

Running the apiary in isolation from the neighbours. In crowded terrain the health of your colonies depends on how the neighbours treat. It is worth reaching an understanding, because diseases do not know plot boundaries.

Sources and further reading

• Semkiw P., Institute of Horticulture in Puławy. Reports on the state of beekeeping in Poland (2023, 2024 editions). Source of data on colony numbers, bee density and its regional variation.

• Wilde J. Work on the forage carrying capacity of terrain and the effect of bee density on apiary yields. Basis of the threshold of about seven colonies per square kilometre.

• Kobylińska M. (2021). Regional differentiation of beekeeping in Poland. Wiadomości Statystyczne 66(2): 25-38. On the rise in bee density and the fall in average apiary size.

• Mallinger R. E., Gaines-Day H. R., Gratton C. (2017). Do managed bees have negative effects on wild bees? A systematic review of the literature. PLoS ONE 12: e0189268. A balanced review of the effects of managed bees on wild ones.

• Henry M., Rodet G. (2018). Controlling the impact of the managed honeybee on wild bees in protected areas. Scientific Reports 8: 9308. On the range of competition around an apiary and regulation by distance rather than density.

• Torné-Noguera A. et al. (2016) and Valido A. et al. (2019). On competition detectable already at low density and on the drop in flower visits by wild pollinators at high bee density.

• Cane J. H., Tepedino V. J. (2017). Gauging the effect of honey bee pollen collection on native bee communities. On the enormous quantity of pollen gathered by bee colonies.

• Guides on calculating the honey yield of the forage base and on effective flight range (Pasieka24, Współczesna gospodarka pasieczna), and on migratory apiaries and overcrowding. Background to the parts on flight range and migration.

• Materials on herb-honeys and honey-like products (Stara Miodziarnia, PszczelaMatka.pl, Łysoń) and on adulterating honey with syrup (Pasieka24). Basis of the part on mid-season feeding and pseudo-honeys.