Category: insects

Readers’ wildlife photos

September 1, 2025 • 8:15 am

Today we have an educational text-and-photo post by Athayde Tonhasca Júnior; the subject is fire and bees. Athayde’s text is indented, and you can enlarge the photos by clicking on them.

Bees and the Goldilocks’ principle 

If we were asked about our impression of what Israel looks like, chances are that most people would mention ‘desert’. Indeed, over 60% of the country is covered by inhospitable, barren land. But Israel is quite diverse for its size, accommodating fertile plains, grassland, mountains and woodland. And, perhaps to the surprise of many, the country is a haven to bees, the members of the clade (a group of organisms sharing an ancestor) Anthophila. With 1,500 to 2,000 species—estimates vary because the taxonomy of local bees is poorly known—Israel is the world’s most bee-rich nation per unit of area. That’s unsurprising, as parts of the country have plenty of what most bees need: dry, sunny and open habitats with enough water and an abundance of flowers. These features are well represented in Mount Carmel National Park, a typical Mediterranean ecosystem of pine and oak woodland and maquis – a plant community composed of dense thickets of leathery, thorny shrubs and small trees.

Maquis vegetation at Mount Carmel, Israel’s largest (10,000 ha) conservation unit and a UNESCO biosphere reserve © netanel_h, Wikimedia Commons:

Mount Carmel is particularly dear to Israelis for its biodiversity, archaeological sites, geological formations and cultural heritage. Nonetheless, the park has a history of setbacks in the form of forest fires. Some of them are expected: a habitat with lengthy and intense dry seasons, high temperatures and a build up of plant biomass (fire fuel) is likely to go up in flames now and then after lightning strikes. But many wildfires have resulted from arson, an inevitable upshot of human encroachment and agriculture expansion.

Fire at Mount Carmel © Israel Police Air Unit, Wikimedia Commons:

We may see natural or manmade fires as ecological disasters, but that’s not necessarily the case. Wildfires have been part of the natural cycle of many ecosystems for millennia, and have a rejuvenating effect. Fire promotes plant diversity by clearing thick overgrowth and dead vegetation, opening areas to sunlight so that seedlings can germinate, curbing dominant species that outcompete others, and releasing plant nutrients into the soil. Many fire-adapted plants bloom and grow quickly after a fire, taking advantage of the sudden and welcoming changes.

Ecological succession one year (L) and two years after a wildfire in an Estonian pine forest © Hannu, Wikimedia Commons:

Mediterranean woodland and maquis are well-adapted to the fire regime, and some animals also benefit from periodic conflagrations. Bees are a case in point.

The vegetation in Mount Carmel recovers promptly after a fire by re-sprouting and seed germination, resulting in a profusion of blooming. Bees from surrounding areas quickly move in to exploit the sudden bonanza of pollen and nectar, and also of nesting sites made available by the recently exposed soil. The diversity of flowering plants and bees are the highest during the first two years after a fire, with both declining steadily as plant succession takes place – until another fire strikes (Potts et al., 2003). These periodic, small scale cataclysms suit the bee fauna very well, so much so that some 600 to 700 species have Mount Carmel as their home.

Mount Carmel is not an isolated case of a fire-friendly bee habitat. At McLaughlin Reserve in northern California, grassland recovering from a fire showed increased floral density and a prolonged flowering season. These effects were well-received by the area’s main pollinator, the yellow-faced bumble bee (Bombus vosnesenskii), as burned patches were foraged more intensively than intact patches (Mola & Williams, 2018).

The rightly named yellow-faced bumble bee, a wildfire opportunist © Kevin Cole, Wikimedia Commons:


At Great Smoky Mountains National Park, Tennessee, post-fire plots had increased abundance of wingstem (Verbesina alternifolia), a favourite of bees, butterflies and other insects. As a result, insect visitation to wingstem flowers was about 50% greater in burned plots than in intact plots (Van Nuland et al., 2013). Other studies have found similar trends: bees and other pollinators are not only resilient to wildfires, but tend to be more abundant and diverse after a fire (Carbone et al., 2019). Those findings have far-reaching implications because many bee-rich habitats, including the world’s hotspots of bee biodiversity such as the Mediterranean Basin, southwestern USA, eastern South Africa and southeastern Australia (Orr et al., 2021) burn down regularly.

Wingstem, a source of nectar for insects and seeds for birds, is helped by wildfires © Fritzflohrreynolds, Wikimedia Commons.

We may be tempted to conclude that habitats catching fire willy-nilly is a good thing, but that would be a catastrophically wrong conclusion. Just as for many situations in the natural world and even for our choices in life, it’s all a matter of proportion. Fires that are too frequent, too extensive, last for too long or start too early in the season, are not at all beneficial. Intense fire regimes curb the re‐establishment of plant and animal species, promote soil erosion and deplete the soil of nutrients. With time, habitats become drastically altered and impoverished.

The positive side of wildfires is best understood through the Goldilocks principle of ‘just right’ predicted by the Intermediate Disturbance Hypothesis. According to this model, cyclic, moderate fire regimes foster plant diversity, which benefits bees. Out of control fires destroy everything, while the absence of fires reduces plant diversity because of competition.

The Intermediate Disturbance Hypothesis. At low levels of disturbance (I), species richness is low because the strong competitors eliminate weaker ones; at high levels (III), species richness is also low because all species are affected; at moderate levels (II), competition is abated, so diversity is maximized © Wikimedia Commons:

Moderated levels of habitat burning seem to have worked well for bees and other species, but the future is bleak. Extreme heat waves and droughts are becoming more frequent as the planet continues to warm. Higher temperatures and drier landscapes help create ideal conditions for increased fire activity, as demonstrated by recent fierce, destructive wildfires around the world. These changes are bound to impact pollinators, pollination systems and biodiversity in general, but we can only guess to what extent. Goldilocks wouldn’t be happy about that.

Fireweed (Chamaenerion angustifolium) and other flowers growing back after the devastating 1988 Yellowstone fire. Such recoveries may become increasingly rare as wildfires intensify © U.S. National Park Service, Wikimedia Commons.

Spot the grasshopper!

September 1, 2025 • 7:30 am

Reader Mark Richardson sent us a “spot the. . . ” photo.  As he wrote:

Yesterday, I spotted this grasshopper land on a gravel path. I could barely spot it even though I knew where it landed. This might be considered a cruel “spot the…” post, but I couldn’t resist. It is remarkably cryptic against the grey gravel. . . . Not sure of the species, but my best guess is a Pallid-winged grasshopper (Trimerotropis pallidpennis).

Can you spot it (this is pretty hard)?  If you do, don’t say where it is, though you can say “Found it!” in the comments.  There will be a reveal at 11 a.m. Chicago time. Click to enlarge the photo:

Readers’ wildlife photos

August 22, 2025 • 8:15 am

Today I’m assembling photos from readers who sent in a small number.  Their captions are indented, and you can enlarge the photos by clicking on them.  I’m assuming all ducks are mallards (Anas platyrhynchos).

DUCKS from Peter Fisher:

I came across this family of ducks in a rather lovely setting in Rydal Water in the English Lake District. Mum is clearly keeping watch. There were six ducklings, (one must have escaped the frame).

From Christopher Moss:

Some more for your stash. I received the 2x teleconverter today, so these were taken with the full frame equivalent of a 1200mm lens! I need to practice some more with it, as it is prone to camera shake, but there is promise there.

Blue Jay (Cyanocitta cristata), Muskrat (Ondatra zibethicus) and a damselfly (probably an Eastern Red Damsel, Amphiagrion saucium)

 

From Richard Kleinknecht:

THE HUNGRY AMERICAN BULLFROG (Lithobates catesbeianus)

                               

 The California Department of Fish and Wildlife writes (click here)

“Adult American bullfrogs have voracious appetites and will eat anything they can fit into their mouths, including invertebrates, birds, bats, rodents, frogs, newts, lizards, snakes, and turtles.  Bullfrog tadpoles mainly eat algae, aquatic plant material, and invertebrates, but they will also eat the tadpoles of other frog species.  As a result of these feeding behaviors, all life stages of bullfrogs prey upon and are able to out-compete native frogs and other aquatic species.  Additionally, bullfrogs are a known carrier of chytrid fungus, which causes the potentially fatal skin disease in frogs called chytridiomycosis.  Chytridomycosis is believed to be a leading cause of the decline of native amphibian populations all over the world and responsible for the extinction of over 100 species since the 1970s.”.

Apparently, the American bullfrog will, or will try to, eat anything that won’t eat it first.  My extended family member, Eleanor, knew that bullfrogs had exterminated her singing chorus frogs, (genus Pseudacris, multiple species) and was not terribly surprised when she came upon this bullfrog attempting to swallow a pre-deceased adult bird, one that ultimately proved to be too large for consumption – but the frog came very close to swallowing something nearly as large as itself!

From Sharon Diehl:

Bald Eagle (Haliaeetus leucocephalus) pair atop Transform Tower #199, Wally Toevs Pond, Walden Wildlife Habitat, Boulder, Colorado. I have photographed this mated pair for years at Walden Wildlife Habitat, where they hang out atop the transform towers that overlook Wally Toevs Pond. They aren’t always successful breeders, but they keep at it, together year after year.

Red-tailed Hawk (Buteo jamaicensis) hunting at my backyard bird feeders–where, alas, it caught a bird–at least it was a Starling. I know the raptors have to eat, too:

Downy Woodpecker (Dryobates pubescens), on the Hornbeam tree I believe, waiting for the flicker to leave the suet feeder–my backyard, Boulder, Colorado.

Osprey (Pandion haliaetus) in a tree, overlooking a lake in East Boulder Community Park, Boulder Colorado.

. . . and more DUCKS from reader A. C. Harper:

Two ducks making the most of pondweed on water at Fairhaven near the Norfolk Broads. Pictures taken on holiday at South Walsham July 2025.

Readers’ wildlife photos

August 20, 2025 • 8:15 am

Athayde Tonhasca Júnior has returned with an edifying photo-and-text contribution, centering on his speciality, pollination. And once again, these phenomena show the powers of natural selection to affect both morphology and behavior.

Athayde’s captions are indented, and you can enlarge his photos by clicking on them.

O, what a tangled web we weave when first we practise to deceive

It’s a bright early morning in the American desert of southern Arizona, and a bee prepares to land on the flowers on the top of a fishhook barrel cactus (Ferocactus wislizeni). The approaching bee belongs to a group of solitary, ground-nesting species that specialize on the flowers of several cactus species, so unsurprisingly they are labelled cactus bees. These visitors are most welcome to the fishhook barrel cactus, as it depends entirely on them for pollination.

‘Fishhook’ says it all: the fishhook barrel cactus is well-armed against plant munchers © Bernard Gagnon, Wikimedia Commons:

Alas, the impending pollinating event does not happen because just before alighting, the bee spots danger: southern fire ants (Solenopsis xyloni) are milling about. Ants in general have a mood ranging from annoyed to furious, and fire ants live up to the family reputation: they readily attack perceived intruders, humans included, biting and injecting them with venom. Wisely, the bee flies away.

‘Fire’ says it all: despite its small size, the southern fire ant is aggressive and inflicts painful stings © Jake Nitta, Wikimedia Commons:

Fire ants are ground dwellers, spending their days scouring the soil surface for seeds and dead insects. They are also keen on sweet foodstuffs such as honeydew (the sugar-rich liquid secreted by aphids and some scale insects) and nectar, which explains their presence on the fishhook barrel cactus: they were gathering extrafloral nectar exuded from specialised spines on the top of the plant.

Close to 1.8% of all vascular plants, or ~4,000 species distributed across 108 families (these numbers are ever increasing), bear extrafloral nectaries (EFN): nectar-secreting glands located anywhere in the plant outside the flowers. Darwin believed these glands had the function of discarding waste or toxins. One of his correspondents, the Italian botanist Federico Delpino, rejected the idea: plants wouldn’t squander nectar, an expensive resource, just to flush out unwanted substances. Based on information he gathered from various plant species, Delpino concluded that the main purpose of EFN was to attract ants.

Extrafloral nectaries can be found on stipules (A), leaf bases (B) petioles (C), or more than one structure (D) © Holopainen et al., 2020:

Luring ants with nectar hints of pollinating relationships, but this possibility can be discarded for the majority of EFN-bearing plants. Most ants do not have pollen-collecting structures and are too small for the task. But the main barrier to ants’ contribution to pollination is their chemical defences that prevent the proliferation of pathogens but also inhibit pollen germination and the growth of pollen tubes. As a result, there are only 30 or so known cases of myrmecophily (ant pollination) among the thousands of insect-pollinated species. Plants entice ants with their EFN for an entirely different reason: to recruit a cohort of mean-spirited bodyguards.

Numerous studies have shown that ants attracted to EFN protect plants by attacking plant-munchers or disrupting their egg laying. Some trees, mostly in the tropics, have developed mutualistic associations with ants; they shelter their visitors in domatia (hollow chambers) and feed them with food bodies (nutrient-rich structures) and extrafloral nectar. In return, ants keep the plant’s enemies away: some even snip off epiphytes (plants that grow on the surface of another plant). If you ever leaned against one of these myrmecophytes (‘ant plants’) for a break during a hike, you probably were quickly encouraged to move along by some irate ants.

Ants patrolling the myrmecophyte tree bullhorn acacia (Vachellia cornigera) © Ryan Somma, Wikimedia Commons:

However, just like advertising a party fuelled by free beer on social media, encouraging ant visitors can have disastrous outcomes. In some circumstances, ants extend their foraging bouts from EFN to flowers where they may deplete the nectar – and even pollen – intended for pollinators. Ants may damage reproductive structures, sometimes castrating flowers by nibbling on stamens and pistils. And when ants are about, other flower visitors tend to give them a wide berth. That’s what happens when a fishhook barrel cactus is occupied by EFN-seeking southern fire ants. As a consequence, bees visit flowers less frequently and for less time, resulting in fruits with smaller and lighter seeds when compared to plants with no fire ants (Ness, 2006). This is not an isolated case. The presence of the common red ant (Myrmica rubra) on flowers can cause the common eastern bumble bee (Bombus impatiens), one of the most abundant bumble bees in eastern North America, to collect and deposit less pollen. The scent of ants alone is sufficient to put bumble bees off (Cembrowski et al., 2014).

The common red ant, a Palaearctic native and invasive to North America © Gary Alpert, Wikimedia Commons:

Because ants often decrease the species diversity of flower visitors as well as the frequency and duration of visits, the Austrian botanist Anton Joseph Kerner suggested another purpose of extrafloral nectar: bribery. EFN would turn ants’ attention away from the flowers, thus reducing their conflict with pollinators, while retaining ants’ protection for other parts of the plant (Kerner, 1878). The Distraction Hypothesis, as Kerner’s proposal is known today, may sound farfetched, but has been demonstrated experimentally. In one case, researchers simply blocked EFN on the Mexican ant‐plant Turnera velutina and observed the results. Blocking reduced the number of ants patrolling EFN, increased the proportion of flowers occupied by ants and reduced plant reproductive success (Villamil et al., 2019).

(b): EFN on the underside of a T. velutina leaf; (c): clogged and control leaves © Villamil et al., 2019:

What we know so far: ants can be plant guards, as suggested by Federico Delpino, or plant exploiters, according to Anton Joseph Kerner. As ant protection is mostly associated with EFN-bearing plants, which make up a minority of flowering plants, it’s safe to assume that ants on plants are mostly bad news. But, as it is invariably the case in biology, the plot thickens.

For the EFN-bearing T. velutina, the more aggressive the ants, the  more vigorously flower visitors are deterred; but, surprisingly, deterrence reduces self-pollination and increases cross-pollination (Villamil et al., 2022), probably because pollinators that take their chances hang on to flowers just long enough to collect or deposit pollen, thus increasing the rate of flower visitation. For the South American scrubs Banisteriopsis campestris and B. malifolia, the presence of ants around flowers reduces visitation by smaller bees. But larger bees, which are likely to be better pollinators, are not bothered by ants, a positive outcome for the host plants (Barônio & Del-Claro, 2017).

Ants keep small bees away from these B. campestris flowers, but large bees are not affected © João Medeiros, Wikimedia Commons:

Ants are found everywhere except Antarctica and a few remote islands, and are incredibly important for all sorts of ecological services, from decomposition to recycling of nutrients, control of plant-eating insects, improving soils and dispersing seeds. They achieve all of that thanks to their mindboggling numbers. The renowned myrmecologist E. O. Wilson estimated that 1015 to 1016 ants crawl on Earth’s surface at any given time (that’s quadrillions, figures usually discussed in astronomy). A later appraisal fine-tuned the number to 20 × 1015 individuals, which corresponds to ∼12 megatons of carbon. This is more than the combined biomass of all wild birds and mammals, and is equivalent to ∼20% of human biomass (Schultheiss et al., 2022). Another study following a different methodology suggested a population size of 5 × 1016, excluding arboreal ants (Rosenberg et al., 2023). So Wilson wasn’t far off, as a billion here or a billion there is not that important when we are talking quadrillions. For comparison, there are some 7.9 × 109 human beings on the planet.

Depending on the species involved, ants may have substantial positive or negative effects on the pollination game, even though they play a mediocre role as pollinators. When ants are about, pollination is no longer a quid pro quo between pollinating insects and flowers. The party crasher must be accounted for.

A silky ant (Formica fusca) collecting nectar from a germander speedwell (Veronica chamaedrys) flower © Gilles San Martin, Wikimedia Commons:

Readers’ wildlife photos

August 15, 2025 • 8:15 am

Today we have photos from Montana taken by Gregory Zolnerowich (there are two exceptions; see below). Gregory’s captions are indented, and you can enlarge the photos by clicking on them.

I recently spent 10 days in Livingston, Montana, visiting a friend and meeting some fellow Kansans for a bit of rafting and camping on the Yellowstone River south of Livingston. Attached are some wildlife photos that might be suitable for WEIT. Another person in our group took the photos of the bald eagle and sandhill cranes but I have permission to share them.

The marvelous scenery of the Paradise Valleyl; the Yellowstone River flows north through it. We camped one night alongside this small side branch of the river. There were small American black bear (Ursus americanus) tracks in the mud so we had to store our food away from the tents:

Hello, do you have a minute to hear about the good news from our lord and savior, Bambi?:

This is the same mule deer (Odocoileus hemionus) as in the previous photo. I stepped out on the deck and it was quite unafraid of me. The friend I was visiting has a number of raised garden beds and grows a variety of vegetables. Her active gardens have deer fencing around them to protect the plants. Possibly the same deer would come around in the early evening and eat apples that had fallen from her apple tree:

This is probably a mountain cottontail (Sylvilagus nuttallii): there were many of these around our cabin. They are the real marauders of the garden and will chew through the plastic deer fencing to graze and raze the garden veggies:

Montana has at least four species of chipmunks. I think this is the least chipmunk (Neotamias minimus). It would skitter and scurry about and was entertaining to watch:

We watched this bald eagle (Haliaeetus leucocephalus) glide in and land on the shore acrossfrom our campsite. It then waded into the water, caught a fish, and flew away. I’ve never seen a bald eagle do that:

Sandhill cranes (Antigone canadensis) are large and majestic. We could hear them calling during the early evening. Their call is quite unique:

Along with bald eagles, ospreys (Pandion haliaetus) also were abundant. We floated right under this one, I was surprised it did not fly off. Look at that hooked beak!:

There are a number of ready-made nesting platforms along the river to keep the ospreys and eagles from nesting on the power poles. This one has ospreys but sometimes we would see an eagle using the platforms:

I was suprised to see this caterpillar out and about on a chilly morning. It appears to be Glover’s silkmoth, Hyalophora gloveri (Saturniidae):

The closest ID I’ll give for this caterpillar is perhaps Arctiinae:

Readers’ wildlife posts

July 28, 2025 • 8:15 am

Regular Mark Sturtevant has sent in a passel of photos of insects and other arthropods. His captions are indented and you can enlarge his photos by clicking on them:

Now that our host is back from his travels, I can share another set of pictures of arthropods from near where I live, which is in eastern Michigan. These were done over the previous season.

First up are early immature grasshoppers. The first two are a Coral-winged Grasshopper nymph (Pardalophora apiculata). This grows into what I think is the largest ‘hopper species in our area. Adults have lovely pinkish-orange wings, as the attached picture shows. The second is a Northern Green-striped nymph (Chortophaga viridifasciata) – another early-season species.

Next up is a small Aphid Wasp (Pemphredon sp.) that had emerged from winter hibernation. These solitary wasps provision their nest with aphids, and on one occasion while photographing a colony of aphids, I was approached by one of these that had flown near, snatched up an aphid right in front of me, and flew away. I swear I could hear the little aphid screams receding into the distance.

Here is a portrait of an Eastern Black Carpenter Ant (Campanotus pennsylvanicus). I am exploring more artsy modes of photography, and this black and white is an early attempt.

In the previous season I had the good fortune to find two species of Saturniid (giant silk moth) caterpillars, and one was shown here recently. Their cocoons spent the winter in our refrigerator, of course, and good luck continued since I was able to photograph the emerged adults before they were quite ready to fly. So here are pictures of a Luna Moth (Actias luna), followed by pictures of a Polyphemus Moth (Antheraea polyphemus). The latter pictures were taken with a wide-angle macro lens, which is by far the most challenging lens that I have since you have to basically take pictures without being able to see if it’s in focus. Wide angle macro is a welcome change, however, since with this one can see much more the surrounding environment of the subject rather than the narrow field of view that is normally presented by a regular macro lens.

Finally, one subject I’ve been meaning to get back to are House Centipedes (Scutigera coleoptrata). These fast-moving animals get pretty big, as shown in the attached picture, and they will at times run up and down our walls, usually near the fireplace, which is probably how they get inside. The hostility they inspire from nearly everyone seems unfair since their only reaction to us is to run away. So here is one, photographed while being contained in the bathtub (as one does of course), followed by a portrait. The latter is an attempt to show that they really are sort of cute. The things that look like fangs are called forcipules, and they are actually a modified pair of front legs. They don’t bite. I swear.

Readers’ wildlife photos

July 26, 2025 • 8:15 am

We’re back, and with a text-and-photo contribution on beekeeping by Athayde Tonhasca Júnior. His prose is indented, and you can enlarge his photos by clicking on them.

No vacancies

Born in in the village of Breznica in the Austro-Hungarian empire (in today’s Slovenia), Anton Janša (1734-1773) would never have imagined that 20 May, his day of baptism (a proxy for his unknown birthday), would be celebrated around the world. Trained to be an artist, Anton’s true calling was honey bees. His innovative hive designs and books on beekeeping made him famous among his peers. In 2017, Slovenian beekeepers, backed by the Slovenian government, successfully lobbied the United Nations to designate 20 May as World Bee Day.

A 1973 postage stamp depicting Anton Janša © GetArchive:

Since then, more and more countries and people have joined World Bee Day celebrations. Inevitably, the event’s increasing visibility is a tempting opportunity for cashing in. As the day approaches, the more intense the peddling of bee-themed gin, beer, chocolate bars, fudge, skin creams, lip balms, clothing (“perfect for raising awareness”) and other items of marginal or imaginary connection to bees. The UN’s laudable initiative has another peculiarity: both the preservationist and commercialistic takes on World Bee Day focus largely on the European honey bee (Apis mellifera), giving limited coverage or ignoring altogether the ~20,000 other known species of bees, the members of the clade (a group of organisms sharing an ancestor) Anthophila. That’s unfortunate, as in many situations wild bees equal or surpass A. mellifera as providers of pollination services to wild plants and crops. Even more unfortunately, some initiatives towards the European honey bee are directed at self-promotion and public visibility, but are not guided by sound ecological principles.

The clade Anthophila: essentially a group of vegetarian wasps (Engel et al., 2020) © USGS Native Bee Inventory and Monitoring Program:

Before we proceed, here’s a quiz: what do London’s Ritz Hotel, Buckingham Palace, Lambeth Palace and New York’s Empire State Building, Madison Square Garden and the Chrysler Building have in common, besides being famed? Answer: they all house apiaries on their roofs or adjacent structures. Rooftop beekeeping is not restricted to glamorous landmarks; roofs all over the world are being occupied by hives. The practice has been adopted by companies and organisations and enthusiastically publicised on World Bee Day. One commercial real estate business boasts having installed bee hives on some 2,500 buildings across North America and Europe for honey production and to serve as “biodiversity indicators”. Another property company gives away free hives to its clients “to help bees and boost office morale”.

A Rockefeller Center rooftop, home for thousands of honey bees © Jwilly77, Wikimedia Commons:

High-rise apiculture is perhaps the most stylish form of urban beekeeping, which is growing rapidly around the world. The activity accelerated in the mid-2000s, when we were bombarded daily with news about the imminent demise of honey bees, dragging mankind with them. Well-intentioned urbanites, concerned about the environment, honey bees and the future of humanity, saw beekeeping as an ideal way to help nature – a pleasant, virtuous hobby with a sweet reward with which to impress friends and neighbours.

Alas, the road towards these noble objectives has many potholes. The first is the misconception that the European honey bee is a species at risk. Despite the problems it faces in North America and Europe, beehives and beekeeping are thriving globally. Moreover, honey bees have been managed, moved around and selectively bred for thousands of years. For practical purposes, they are more appropriately treated as livestock than wildlife, an interpretation adopted by legal statutes around the world. The upshot is that a farm animal like the honey bee is not a suitable proxy for biodiversity.

Numbers of managed honey bee colonies, in millions, worldwide (A) and by geographical regions (B) © Osterman et al., 2021:

Honey bees are not endangered and are poor biodiversity indicators, but these are not good reasons to object to urban beekeeping. Trouble arises when there are too many honey bees.

Greater London is a good example of the problem. The city is packed with about 10 hives/km2 – for comparison, farmers keep 2.5 to 5 hives/km2 in crops highly dependent on pollinators such as almonds and apples. Each London hive needs the equivalent of 1 ha of borage (Borago officinalis) or 8.3 ha of lavender (Lavandula spp.) for their supplies of pollen and nectar (Alton & Ratnieks, 2016a): these figures are not sustainable for a significant portion of the city’s area. High hive densities and the proliferation of inexperienced beekeepers bring up another predicament: greater risk of diseases and parasites, which are the bane of honey bees around the world.

Estimated effect of beekeeping on a London’s 1-km grid based on available foraging plants (greenspaces) and number of honey bee colonies © Stevenson et al., 2020:

Honey bees taking food from each other is just the start of the problems caused by high numbers of hives.

When more than one species needs the same resource and there isn’t enough of it to go around, the species will compete for it. A growing body of evidence has shown that a range of wild bees get the raw end of the deal if they are forced to go up against honey bees for pollen and nectar. Honey bees forage up to 6 km from their nests, and they are very good at it. An average colony may collect up to 55 kg of pollen and hundreds of kilos of nectar every year, depending on floral abundance and climatic conditions (Seeley, 1985). These figures add up: a 40-hive apiary collects the pollen equivalent of four million wild bees at high season (June -August); that means that one hive gathers pollen sufficient to produce 100,000 progeny of an average solitary bee species (Cane &  Tepedino, 2017).

The outcompeted wild bees are displaced or forced to shift to less rewarding plant species. Lower reproductive success, smaller body sizes and poor food gathering, all factors that reduce bees’ survival, are frequent outcomes of such interactions. These effects on wild pollinators have been recorded in London and other conurbations overcrowded with honey bees such as Berlin, Montreal, Paris and Zurich. Even more damming, more and more studies demonstrate that honey bees are vectors of parasites and diseases to wild bees, problems aggravated where honey bees are overabundant.

Effect of increasing honey bee abundance on species richness of all wild bees (A) and small wild bees (B) in Montreal, Canada. The coloured figures represent 95% confidence intervals © MacInnis et al., 2023:

Beekeeping promotes well-being, boosts confidence, enhances the feeling of accomplishment, creates opportunities for learning about the natural world and shared experiences with fellow beekeepers – besides the obvious asset of honey for pleasure or profit. But like many of life’s endeavours, there could be too much of a good thing. Densities of 3 to 3.5 hives/km2 have been suggested as precautionary levels to reduce honey bee impact on other species (MacInnis et al., 2023), but these figures are way lower than those found in cities around the world.

Beekeeping on U.S. Department of Agriculture headquarters rooftop in Washington, D.C. A healthy hive will house 50,000 bees by midsummer © USDA, Wikimedia Commons.

U.S. Department of Agriculture (USDA) Agricultural Research Service Biological Science Technician Nathan Rice (in full bee protective suit and hat) and assisted by Biological Science Lab Technician Andy Ulsamer, they are the official beekeepers of the People’s Garden Apiary on the USDA Headquarters’ Whitten Building roof, in Washington, D.C., and are harvesting honey from two colonies on Friday, Sept. 5, 2014. The apiary serves to educate people about this type of pollinator.
These bees can be seen with the USDA Bee Watch camera stream video, of one of these colonies. The link to the camera and to learn more about this apiary and bees, please go to http://www.usda.gov/wps/portal/usda/usdahome?navid=usdabees.
USDA Photo by Lance Cheung.

Responsible beekeepers themselves have been warning about the harmful effects of unrestrained beekeeping on honey bees and wild bees, and have pointed out that creating/restoring/protecting flower patches are much more effective measures to help all pollinators. The rub is that planting flowers does not create the same opportunities for business and politicians to flaunt their green credentials.

In 2014, the Scottish Parliament announced to the world, with much fanfare, the installation of beehives on the building’s rooftop. Honey bee experts Karin Alton and Francis Ratnieks failed to be impressed: One cannot help but be cynical that the real motivation for the hive on the Scottish Parliament building was simply to give politicians a better image. As a way of helping honey bees it is of no value, and may well have had the unintended consequence of reinforcing the now widely held impression that politicians seem more concerned with spin over substance (Alton & Ratnieks, 2016b). Not to be outdone, the UK government quickly followed suit by placing a rooftop hive on, of all places, the headquarters of the department in charge of biodiversity and conservation (Defra). The purpose: “making its own contribution to combat bee declines”. You couldn’t make it up.

A genuine, disinterested bee guardian © Remember, Wikimedia Commons: